All free online tools
Find a useful utility by name, or explore a category.
A Record Lookup
Find IPv4 address records for a hostname.
DNS & NetworkAAAA Record Lookup
Find IPv6 address records for a hostname.
DNS & NetworkAdd Days to Date
Add calendar days with month and leap-year rollover.
Date & TimeAdd Prefix and Suffix
Add a prefix and suffix to each line, including blank lines.
Text & WritingAdSense Revenue Estimator
Estimate revenue from page views and your entered page RPM. This is a scenario, not an earnings prediction.
Calculators & MathAES256 Text Encryption
Encrypt or decrypt text using AES-256-GCM and a password-derived key (PBKDF2-SHA256, 100,000 iterations). The envelope includes random salt, nonce and authentication tag. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperAge Calculator
Calculate completed years, months and days between two dates.
Date & TimeAngle Converter
Convert degrees, radians and turns.
Unit ConvertersAPI Response Formatter
Format an entered JSON API response without fetching a URL.
JSON & DeveloperArea Converter
Convert square metres, hectares, acres and square feet.
Unit ConvertersArgon2 Password Hash Generator
Hash a password with Argon2id, 16 MiB memory, two passes and one thread. Salts are generated securely. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperAspect Ratio Calculator
Reduce positive integer width and height to their simplest ratio.
Calculators & MathAverage Calculator
Calculate the arithmetic mean of a list.
Calculators & MathAVIF Converter
Encode an uploaded raster image as AVIF.
Image & GraphicsBase32 Encoder and Decoder
Encode UTF-8 using RFC 4648 Base32 or decode canonical padded Base32.
JSON & DeveloperBase64 Decoder
Decode Base64 bytes into UTF-8 text.
JSON & DeveloperBase64 Encoder
Encode UTF-8 text as Base64 bytes.
JSON & DeveloperBase64 to Image
Decode and verify an image data URL.
Image & GraphicsBase64 to JSON Converter
Decode Base64 UTF-8 and validate JSON syntax locally.
JSON & DeveloperBBCode to HTML Converter
Convert a bounded subset of BBCode: b, i, u, s, quote and code. Other tags remain literal; all entered HTML is escaped.
Text & WritingBcrypt Password Hash Generator
Hash a password using bcrypt cost 10 and a random salt. Passwords exceeding the bcrypt 72-byte limit are rejected. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperBcrypt Password Verifier
Verify a password against a valid bcrypt hash. Only a boolean result is returned. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperBinary to Text Converter
Decode eight-bit binary bytes into UTF-8 text.
Text & WritingBreak Even Calculator
Calculate units required to cover fixed costs when unit price exceeds variable unit cost.
Calculators & MathBroken Link Checker
Check up to ten same-origin links on a public HTTPS page.
Web & SEOBrowser Storage Inspector
Inspect this origin localStorage and script-readable cookies. HttpOnly cookies and other origins are inaccessible; nothing is sent to the server. This interface works locally in your browser.
JSON & DeveloperBusiness Days Calculator
Count Monday–Friday days, optionally excluding listed holidays.
Date & TimeBusiness Name Idea Generator
Combine your keyword with a small curated word set using random selection. Availability and trademarks are not checked.
Text & WritingCaesar Cipher
Shift Latin letters by an integer offset. This historical cipher provides no modern confidentiality.
JSON & DeveloperCanonical Tag Generator
Generate an escaped canonical link for an absolute HTTP or HTTPS URL.
Web & SEOCanonical URL Checker
Inspect canonical link tags on a public HTTPS page.
Web & SEOCapacitor Code Calculator
Decode a three-digit capacitor code in picofarads; the last digit is the decimal multiplier.
Calculators & MathCase Converter
Switch between sentence, title, upper and lower case.
Text & WritingCharacter Counter
Measure characters, code points and spaces.
Text & WritingChmod Permissions Calculator
Convert three octal permission digits to symbolic rwx permissions and back. Special bits are outside this tool.
JSON & DeveloperChown Command Generator
Generate a shell-quoted chown command for an owner, group and path. The command is never executed.
Web & SEOCIDR Calculator
Calculate an IPv4 CIDR network, mask and range.
DNS & NetworkCNAME Lookup
Read canonical-name aliases.
DNS & NetworkCoin Flipper
Flip 1–1,000 virtual coins with cryptographic randomness and report individual flips and totals.
Text & WritingColor Code Converter
Convert a six-digit hex color to RGB and HSL without uploading an image.
Web & SEOColor Contrast Checker
Calculate WCAG sRGB relative-luminance contrast and AA/AAA text thresholds for two opaque colors.
Web & SEOColor Mixer
Blend two opaque colors by a percentage weight in sRGB component space.
Web & SEOColor Palette Generator
Generate five evenly spaced hue colors from an input color, retaining HSL saturation and lightness.
Web & SEOColor Tint and Shade Generator
Mix a color with white or black by an entered percentage in sRGB component space.
Web & SEOCompound Interest Calculator
Model periodic compounding with fixed principal and rate.
Calculators & MathCountdown Calculator
Measure seconds remaining until a specified instant.
Date & TimeCountdown Timer
Start a countdown from an entered number of seconds. Browser tab throttling can delay visual updates; deadlines use elapsed time. This interface works locally in your browser.
Date & TimeCPM Calculator
Calculate cost per thousand impressions from an entered campaign cost and impression count.
Calculators & MathCRC32 Checksum Calculator
Generate the CRC-32/ISO-HDLC checksum. CRC detects accidental corruption and is not cryptographic authentication. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperCron Schedule Inspector
Validate five-field cron syntax and find the next five execution times in an explicit IANA timezone. The system cron is never modified. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperCSP Header Generator
Generate a restrictive baseline policy and optionally add explicitly entered HTTPS origins for scripts. Review requirements before deploying.
Web & SEOCSR Decoder
Decode a PEM certificate signing request and report its subject and public key details. No certificate is issued. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperCSS Border Radius Generator
Generate border-radius shorthand for four corners in CSS pixels.
Web & SEOCSS Box Shadow Generator
Generate a CSS box shadow using pixel offsets, blur, spread and a hex color.
Web & SEOCSS Button Generator
Generate escaped button HTML and CSS using a label, background color and border radius.
Web & SEOCSS Clamp Calculator
Calculate a fluid font-size clamp from minimum and maximum widths and pixel sizes, using a supplied rem reference.
Web & SEOCSS Filter Generator
Generate brightness, contrast, blur and grayscale CSS filter declarations.
Web & SEOCSS Flexbox Generator
Generate flex layout declarations from supported alignment and direction keywords.
Web & SEOCSS Glassmorphism Generator
Generate translucent background, backdrop blur and a fine border. Browser support for backdrop-filter varies.
Web & SEOCSS Gradient Generator
Generate a linear gradient between two hex colors at a specified angle.
Web & SEOCSS Grid Generator
Generate an equal-column CSS grid with a fixed pixel gap.
Web & SEOCSS Keyframe Generator
Generate a fade-and-translate animation with a bounded duration and vertical offset.
Web & SEOCSS Minifier
Remove CSS comments and optional whitespace conservatively.
Web & SEOCSS Neumorphism Generator
Generate paired light and dark shadows around a selected background color.
Web & SEOCSS Table Styling Generator
Generate table styles using a hex header color, padding and striped rows.
Web & SEOCSS Triangle Generator
Generate an upward-pointing CSS triangle using transparent borders.
Web & SEOCSV Formatter
Parse CSV with quoted fields and re-emit consistent quoted cells. Malformed CSV is rejected rather than guessed.
JSON & DeveloperCSV to Delimited Text
Parse quoted CSV and join each row using a literal delimiter. Output delimiters are not escaped.
Text & WritingCSV to HTML Table
Generate escaped HTML table markup from well-formed CSV. No entered markup is executed.
JSON & DeveloperCSV to JSON
Parse quoted CSV fields into an array of objects.
JSON & DeveloperCSV to SQL Insert Converter
Generate quoted SQL INSERT statements for a simple table identifier. All values are SQL strings; review dialect escaping.
JSON & DeveloperCTR Calculator
Calculate click-through rate from clicks and impressions. Counts must be nonnegative integers.
Calculators & MathData Storage Converter
Compare decimal bytes and binary kibibytes.
Unit ConvertersData Transfer Time Calculator
Estimate seconds from bytes and bits per second. Uses decimal rates and excludes protocol overhead.
Calculators & MathDate Difference Calculator
Compare calendar dates in days and weeks.
Date & TimeDate Format Converter
Format a Gregorian calendar date in a chosen pattern.
Date & TimeDay of the Week Calculator
Find the English weekday of a validated Gregorian calendar date, using UTC to avoid local shifts.
Date & TimeDays Between Dates
Count elapsed calendar days, excluding the end date.
Date & TimeDead Pixel Checker
Cycle full-screen solid colors to inspect your display visually. This cannot repair pixels or measure hardware faults automatically. This interface works locally in your browser.
Image & GraphicsDecimal to Fraction Converter
Convert a finite decimal string to an exact reduced fraction, up to 15 decimal places.
Calculators & MathDelimiter Converter
Join nonempty input lines with a chosen delimiter.
Text & WritingDensity Converter
Convert kilograms per cubic metre, g/cm³ and lb/ft³.
Unit ConvertersDice Roller
Roll 1–100 dice with 2–1,000 sides using uniform random sampling.
Text & WritingDigital Transfer Speed Converter
Convert bit rates and byte rates with decimal prefixes.
Unit ConvertersDiscord Timestamp Generator
Generate Discord timestamp markup from an ISO instant with explicit offset and a supported display style.
Date & TimeDiscount Calculator
Calculate savings and price after a percentage discount.
Calculators & MathDNS Lookup
Query A, AAAA, MX, TXT and NS records from a live resolver.
DNS & NetworkDNS Propagation Checker
Compare answers from Cloudflare and Google DNS over HTTPS.
DNS & NetworkDomain WHOIS/RDAP Lookup
Retrieve domain registration information through RDAP.
DNS & NetworkDPI and PPI Calculator
Calculate diagonal pixels per inch from physical diagonal size. Display scaling is not included.
Calculators & MathDummy Data Generator
Generate clearly synthetic test records with names, example.com email addresses and random integer identifiers.
Text & WritingEmail Authentication DNS Checker
Query real TXT records for SPF, DMARC and an entered DKIM selector using the configured Cloudflare resolver. Policy presence is not a deliverability or cryptographic verification result.
DNS & NetworkEnergy Converter
Convert joules, kilojoules, watt-hours and kilocalories.
Unit ConvertersExponent Calculator
Raise a number to a chosen power.
Calculators & MathExtract Emails
Extract and deduplicate email-shaped addresses. This does not verify mailboxes.
Text & WritingExtract Numbers
Extract signed integers, decimals and scientific notation from text.
Text & WritingExtract URLs
Extract HTTP and HTTPS URLs from text and remove common trailing punctuation.
Text & WritingExtractive Text Summarizer
Select sentences by repeated-word frequency and preserve original order. This is an extractive heuristic, not an AI rewrite.
Text & WritingFactorial Calculator
Calculate exact factorials using arbitrary-sized integers.
Calculators & MathFavicon Generator
Create a 32×32 PNG icon from an uploaded image.
Web & SEOFile Checksum Calculator
Compute actual MD5, SHA-256 and SHA-512 checksums of uploaded bytes. MD5 is included for legacy checksums only. Files are processed temporarily on this server, with an 8 MiB combined upload limit.
JSON & DeveloperFile to Base64 Converter
Encode uploaded binary bytes as Base64 without interpreting or executing them. Files are processed temporarily on this server, with an 8 MiB combined upload limit.
JSON & DeveloperFind and Replace Text
Replace literal text with a new phrase.
Text & WritingFont Preview
Preview entered text with a chosen installed or system font name. No font files or external fonts are loaded. This interface works locally in your browser.
Web & SEOForce Converter
Convert newtons, kilonewtons and pound-force.
Unit ConvertersFraction Calculator
Add, subtract, multiply or divide two rational numbers.
Calculators & MathFraction to Decimal Converter
Divide an integer numerator by a nonzero denominator. Floating point precision applies.
Calculators & MathFrequency Converter
Convert hertz, kilohertz, megahertz and gigahertz.
Unit ConvertersFuel Consumption Converter
Convert L/100 km, km/L and US miles per gallon.
Unit ConvertersGCD Calculator
Find the greatest common divisor of integers.
Calculators & MathGeohash Encoder and Decoder
Encode latitude and longitude into a geohash or decode a geohash to its bounding box and center.
JSON & DeveloperGit Command Reference
Return a command and explanation for a selected common Git action. Destructive actions are labeled; commands are never executed.
Web & SEOGitignore Generator
Generate a small curated gitignore for Node, PHP, Python or generic projects. Review project-specific needs.
Web & SEOGolden Ratio Calculator
Calculate the longer and shorter golden-section parts of a total length.
Calculators & MathGPS Coordinate Converter
Convert signed degrees, minutes and seconds to decimal degrees, or decimal degrees to DMS.
Calculators & MathHaversine Distance Calculator
Estimate great-circle surface distance using a spherical Earth radius of 6,371 km. This is not a road route.
Calculators & MathHeading Structure Checker
Inspect H1–H6 order in pasted HTML.
Web & SEOHex to Text Converter
Decode hexadecimal UTF-8 bytes and reject malformed sequences.
Text & WritingHMAC Generator
Generate HMAC-SHA256 or HMAC-SHA512 using the entered secret and exact message bytes. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperHourly Rate to Salary Converter
Estimate gross salary from hourly rate, hours per week and paid weeks per year.
Calculators & MathHours to Minutes Converter
Multiply decimal hours by 60.
Date & TimeHreflang Tag Generator
Generate hreflang links from language code and URL pairs on separate lines; supports x-default.
Web & SEOHtaccess HTTPS Redirect Generator
Generate an Apache rewrite rule redirecting HTTP to HTTPS for a validated hostname. Review reverse-proxy behavior before use.
Web & SEOHTML Decoder
Decode HTML entities into plain text.
JSON & DeveloperHTML Encoder
Escape markup delimiters as HTML entities.
JSON & DeveloperHTML Entity Obfuscator
Encode Unicode code points as numeric HTML entities. This is reversible and does not prevent scraping.
Text & WritingHTML Minifier
Remove HTML comments and inter-tag whitespace conservatively.
Web & SEOHTML Table Generator
Generate an escaped HTML table from CSV input. The first row becomes the table header.
Web & SEOHTML Tag Stripper
Parse supplied HTML and extract text, excluding script and style contents. Markup is not executed. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperHTML to Markdown Converter
Convert headings, paragraphs, emphasis, links, lists and code from supplied HTML to Markdown. Complex layout and tables are outside this converter. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperHtpasswd Generator
Generate a username and bcrypt hash line for Apache basic authentication. The generated file entry is never installed. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperHTTP Header Checker
Inspect response headers from a public HTTPS URL.
DNS & NetworkHTTP Status Code Checker
Fetch a public HTTPS URL and report its HTTP status.
Web & SEOHTTP Status Code Reference
Look up the standard reason phrase for a supported HTTP status code using Symfony response definitions. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperICO Favicon Generator
Resize an image to 32 by 32 pixels and wrap its PNG payload in a valid single-entry ICO container. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsImage Blur Tool
Apply one to five Gaussian blur passes and return a PNG. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsImage Brightness Adjuster
Add or subtract brightness from each pixel.
Image & GraphicsImage Color Palette Extractor
Sample a bounded grid of image pixels and return the most common quantized RGB colors. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsImage Color Picker
Read RGB and hexadecimal color at a pixel.
Image & GraphicsImage Compressor
Re-encode an image at your chosen JPEG quality.
Image & GraphicsImage Contrast Adjuster
Adjust tonal contrast within a bounded range.
Image & GraphicsImage Cropper
Crop a rectangular region using pixel coordinates.
Image & GraphicsImage Dimensions Checker
Read width, height and pixel count.
Image & GraphicsImage Flipper
Mirror image pixels horizontally or vertically.
Image & GraphicsImage Format Detector
Detect the format from file bytes rather than its extension.
Image & GraphicsImage Grayscale Converter
Remove color while retaining luminance.
Image & GraphicsImage Metadata Remover
Re-encode pixels without the original metadata.
Image & GraphicsImage Metadata Viewer
Inspect EXIF fields when present.
Image & GraphicsImage Pixelate Tool
Apply a square block pixelation filter and return a PNG. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsImage Prompt Builder
Assemble subject, style, lighting and composition into an image prompt. No image generation service is called.
Web & SEOImage Resizer
Resize to exact pixel dimensions with a pixel limit.
Image & GraphicsImage Rotator
Rotate an image clockwise by a chosen angle.
Image & GraphicsImage to ASCII Converter
Sample image brightness into text using a fixed character ramp, with adjustable output columns. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsImage to Base64
Create a data URL from verified image bytes.
Image & GraphicsImage to GIF Converter
Convert a still image into a single-frame GIF. Animated GIF input is unsupported; transparency can be quantized. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsImage Watermark Tool
Draw a short text watermark on an image.
Image & GraphicsInflation Calculator
Estimate inflation-adjusted cost using an entered annual rate. No live price index is queried.
Calculators & MathIP Address Lookup
Retrieve public IP registration data from RDAP.
DNS & NetworkIPv4 to IPv6 Converter
Convert a dotted-decimal IPv4 address to its IPv4-mapped IPv6 representation.
JSON & DeveloperIPv4 Validator
Validate four-octet IPv4 syntax without a network request.
DNS & NetworkIPv6 Subnet Calculator
Calculate IPv6 network and last address from a validated address and prefix using exact BigInt arithmetic. Output is uncompressed hexadecimal.
JSON & DeveloperIPv6 Validator
Validate compressed and expanded IPv6 syntax locally.
DNS & NetworkISO 8601 Converter
Normalize an offset-qualified instant to ISO 8601 UTC.
Date & TimeJPG to PNG Converter
Convert JPEG pixels into lossless PNG.
Image & GraphicsJSON Beautifier
Pretty-print nested JSON with two-space indentation.
JSON & DeveloperJSON Difference Checker
Compare parsed JSON values recursively and report added, removed and changed paths. Object key order is ignored.
JSON & DeveloperJSON Escape Tool
Encode text as a JSON string literal.
JSON & DeveloperJSON Formatter
Parse JSON and indent it for readability.
JSON & DeveloperJSON Minifier
Remove unnecessary whitespace from valid JSON.
JSON & DeveloperJSON to CSV
Export an array of flat objects as RFC-style CSV.
JSON & DeveloperJSON to Go Struct Generator
Infer a Go struct with JSON tags from an object sample. Mixed arrays use interface{}; keys that collide after identifier normalization are rejected.
JSON & DeveloperJSON to PHP Array Converter
Generate a PHP array literal from JSON values. Nested arrays and objects are preserved.
JSON & DeveloperJSON to Python Dict Converter
Generate Python dictionary and list literals, mapping booleans and null to Python keywords.
JSON & DeveloperJSON to TypeScript Type Generator
Infer a TypeScript type from a sample JSON object, including nested objects, arrays and nullable values. Sample inference does not define all valid API inputs.
JSON & DeveloperJSON to XML
Convert JSON values into typed XML nodes.
JSON & DeveloperJSON to YAML Converter
Convert JSON to YAML using the installed Symfony parser. Numeric precision follows PHP JSON parsing. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperJSON Unescape Tool
Decode a JSON string literal into original text.
JSON & DeveloperJSON Validator
Check JSON syntax and report parsing errors.
JSON & DeveloperJSONL Formatter
Validate newline-delimited JSON and emit one compact JSON value per nonblank line.
JSON & DeveloperJulian Date Converter
Convert an ISO instant with explicit offset to astronomical Julian Date. This is a continuous day count, not the Julian calendar.
Date & TimeJWT Decoder
Inspect JWT header and payload locally without verifying its signature.
JSON & DeveloperJWT HS256 Signature Verifier
Verify an HS256 JWT signature with a supplied shared secret. Report time claims separately; issuer and audience trust must be assessed independently. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperKeyboard Key Tester
Focus this tool and press keys to inspect key, code, modifier flags and repeat state. No key events outside this interface are recorded. This interface works locally in your browser.
JSON & DeveloperKeyword Density Analyzer
Measure exact word occurrences relative to total words.
Web & SEOLCM Calculator
Find the least common multiple of integers.
Calculators & MathLeap Year Checker
Apply Gregorian century and 400-year leap rules.
Date & TimeLED Series Resistor Calculator
Estimate series resistance and resistor dissipation from supply, forward voltage and current in milliamps.
Calculators & MathLength Converter
Convert metres, kilometres, centimetres, inches and feet.
Unit ConvertersLine Break Remover
Replace line breaks with single spaces without changing other characters.
Text & WritingLine Counter
Count newline-delimited lines, including blank lines.
Text & WritingLoan EMI Calculator
Estimate fixed monthly payments on an amortizing loan.
Calculators & MathLocal Notepad
Edit text with automatic localStorage saving on this browser. Shared-device users should clear their note when finished. This interface works locally in your browser.
Text & WritingLocal Time to UTC
Resolve a local time to UTC with an explicit DST ambiguity choice.
Date & TimeLocal Todo List
Add newline-separated tasks, mark them done and delete them. State is saved in this browser localStorage. This interface works locally in your browser.
Text & WritingLorem Ipsum Generator
Generate readable filler paragraphs for layout testing.
Text & WritingLowercase Converter
Convert every letter to lowercase.
Text & WritingMAC Address Generator
Generate a random locally administered unicast MAC address. It does not identify a hardware manufacturer.
Text & WritingMarkdown Table Generator
Generate a Markdown table from CSV, escaping pipes and replacing cell newlines with HTML breaks.
Web & SEOMarkdown to HTML Converter
Render CommonMark with raw HTML stripped and unsafe links disabled. Output is displayed as source, not injected into this page. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperMatrix Calculator
Add, multiply or transpose rectangular JSON numeric matrices up to 20 by 20.
Calculators & MathMD5 Hash Generator
Generate an MD5 hexadecimal checksum. MD5 is unsuitable for password storage or collision-resistant signatures. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperMedian Calculator
Find the middle value of an ordered list.
Calculators & MathMeme Caption Generator
Place printable ASCII top and bottom captions on an image using a fixed built-in font. Long captions can be clipped on small images. Uploads are limited to 8 MiB and 16 megapixels; processing is temporary on this server.
Image & GraphicsMeta Description Length Checker
Count description characters without promising search snippet length.
Web & SEOMeta Tag Generator
Generate escaped HTML title, description and canonical tags from supplied values.
Web & SEOMeta Title Length Checker
Count title characters against an editorial guideline.
Web & SEOMIME Type Lookup
Look up registered MIME types for a filename extension using the installed Symfony MIME database. This is an extension mapping, not content verification. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperMinutes to Seconds Converter
Multiply decimal minutes by 60.
Date & TimeMorse Code Translator
Translate Latin letters and digits to international Morse code or decode space-separated symbols; slash separates words.
Text & WritingMouse Click and Scroll Tester
Use the test area to inspect pointer buttons, double clicks and wheel deltas. Events are observed only within that area. This interface works locally in your browser.
JSON & DeveloperMouse DPI Converter
Preserve effective DPI by converting sensitivity between mouse DPI settings. Game yaw differences are not inferred.
Calculators & MathMX Record Lookup
Inspect mail exchanger priorities and destinations.
DNS & NetworkNATO Phonetic Alphabet Converter
Spell Latin letters with the NATO alphabet. Digits and punctuation remain unchanged.
Text & WritingNginx Server Config Generator
Generate a static-site Nginx server block for a hostname and absolute document root. HTTPS and PHP handling require deployment-specific configuration.
Web & SEONS Record Lookup
Find authoritative nameserver records.
DNS & NetworkNumber Base Converter
Convert signed integers between bases 2 through 36.
Unit ConvertersNumber to Words Converter
Spell signed integers in English up to 999,999,999,999,999. Decimals are rejected.
Text & WritingOhms Law Calculator
Calculate current and power from positive resistance and voltage. Units are volts, ohms, amperes and watts.
Calculators & MathOnline Stopwatch
Start, pause and reset a monotonic elapsed-time display; lap times are recorded locally. This interface works locally in your browser.
Date & TimeOpen Graph Preview
Extract Open Graph metadata from pasted HTML.
Web & SEOOpen Graph Tag Generator
Generate escaped Open Graph title, description, URL and image tags.
Web & SEOPacket Payload Calculator
Subtract entered header overhead from an MTU to estimate payload capacity. This does not discover a network path MTU.
Calculators & MathParagraph Counter
Count paragraphs separated by blank lines.
Text & WritingPassword Entropy Estimator
Estimate a character-pool upper bound assuming independent uniform character selection. Human-chosen passwords can have much less entropy; no crack time is claimed.
Calculators & MathPayment Processing Fee Calculator
Estimate net proceeds using your own percentage and fixed fee. No current processor pricing is assumed.
Calculators & MathPercentage Calculator
Calculate a chosen percentage of a value.
Calculators & MathPercentage Change Calculator
Measure relative change from an original value.
Calculators & MathPNG to JPG Converter
Flatten transparency onto white and export JPEG.
Image & GraphicsPomodoro Timer
Alternate entered work and break intervals with start, pause and reset controls. No notification or external service is required. This interface works locally in your browser.
Date & TimePower Converter
Convert watts, kilowatts and mechanical horsepower.
Unit ConvertersPressure Converter
Convert pascals, kilopascals, bar, atmosphere and psi.
Unit ConvertersPrime Factorization Calculator
Factor an integer from 2 to 10^12 by bounded trial division.
Calculators & MathPrime Number Checker
Test integer primality using bounded trial division.
Calculators & MathProfit Margin Calculator
Calculate gross profit, margin and markup from selling price and cost.
Calculators & MathPrompt Structure Builder
Organize supplied task, context, constraints and output format into a reusable prompt. No AI model is called.
Web & SEOPTR Record Lookup
Resolve a public IP address to its reverse DNS name.
DNS & NetworkPunycode Encoder and Decoder
Convert domain names between Unicode and ASCII IDNA using the installed IDN implementation. This does not register or resolve a domain. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperRandom Choice Picker
Choose one nonblank input line using cryptographically random rejection sampling.
Text & WritingRandom Number Generator
Generate an unbiased integer in an inclusive range.
Calculators & MathRandom Password Generator
Generate a password with rejection-sampled browser cryptographic randomness from letters, digits and optional symbols.
Text & WritingRandom Secret Token Generator
Generate 16–64 random bytes using browser crypto and encode them as hexadecimal.
Text & WritingRandom Text Generator
Generate randomly selected words with cryptographic randomness.
Text & WritingRatio Calculator
Reduce a pair of positive integers to simplest terms.
Calculators & MathReadability Score Calculator
Estimate Flesch reading ease, Flesch-Kincaid grade and Gunning Fog using an English vowel-group syllable heuristic.
Text & WritingREADME Markdown Generator
Generate a project README from a title, description, installation steps and usage text.
Web & SEORedirect Checker
Inspect a bounded public HTTPS redirect chain.
Web & SEORegex Pattern Reference
Return a curated JavaScript regex for email-shaped text, integers, hex colors or UUID v4. Matching alone does not establish validity of an external resource.
Web & SEORegex Tester
Test a JavaScript regular expression in a time-limited worker.
JSON & DeveloperRemove Duplicate Lines
Keep the first occurrence of each exact line.
Text & WritingRemove Extra Spaces
Collapse repeated whitespace into single spaces.
Text & WritingRepeat Text Generator
Repeat text with a separator, capped at 100,000 output characters.
Text & WritingResistor Color Code Calculator
Decode a four-band resistor into resistance and tolerance using standard color digits and multipliers.
Calculators & MathReverse DNS Lookup
Query live PTR records for a public IP address.
DNS & NetworkRobots.txt Generator
Generate crawler rules and an optional sitemap directive.
Web & SEORobots.txt Tester
Test path rules for a chosen user-agent using longest-match precedence.
Web & SEOROI Calculator
Calculate return on investment from initial cost and final proceeds, excluding tax and time value.
Calculators & MathROT13 Encoder and Decoder
Apply the reversible ROT13 substitution to Latin letters.
JSON & DeveloperRPG Character Name Generator
Generate names from a curated fantasy syllable set. These are fictional combinations, not a comprehensive cultural naming model.
Text & WritingRSA Key Pair Generator
Generate a 2048-bit RSA key pair using OpenSSL. The private key is returned only in the response; save it securely. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperSales Tax Calculator
Calculate tax and total from a pretax price.
Calculators & MathSchema Markup Generator
Generate WebApplication or Organization JSON-LD from supplied values.
Web & SEOSchema Markup Validator
Check local JSON-LD structure without implying search-engine approval.
Web & SEOScientific Calculator
Evaluate arithmetic, powers and common mathematical functions.
Calculators & MathScientific Notation Converter
Convert a finite real number to scientific notation with chosen significant digits.
Calculators & MathSecurity Headers Checker
Inspect security headers returned by one public HTTPS request from this server. Header presence alone does not establish security.
DNS & NetworkSemantic Version Calculator
Validate stable major.minor.patch versions and increment major, minor or patch. Prereleases are outside this tool.
JSON & DeveloperSentence Counter
Count sentences separated by terminal punctuation.
Text & WritingSERP Snippet Preview
Preview a title, URL and description as an illustrative search snippet.
Web & SEOSHA1 Hash Generator
Generate a SHA-1 hexadecimal checksum. SHA-1 is unsuitable for collision-resistant security designs. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperSHA256 Hash Generator
Generate a SHA-256 hexadecimal digest of the exact UTF-8 input bytes. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperSHA512 Hash Generator
Generate a SHA-512 hexadecimal digest of the exact UTF-8 input bytes. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperSimple Interest Calculator
Calculate interest without compounding.
Calculators & MathSimple JSONPath Selector
Select JSON data using $ root, dot identifiers, numeric array indices, quoted bracket keys and wildcard segments. Filters, scripts and recursive descent are unsupported.
JSON & DeveloperSitemap Validator
Validate local sitemap XML structure and URL count.
Web & SEOSlug Generator
Turn a title into a readable URL slug.
Text & WritingSOA Record Lookup
Inspect zone authority, serial and timing values.
DNS & NetworkSocial Media Character Counter
Count Unicode code points and compare against your entered character budget. Platform rules can differ, especially for links.
Web & SEOSpeed Converter
Convert metres per second, kilometres per hour, mph and knots.
Unit ConvertersSquare Root Calculator
Find a real square root of a nonnegative number.
Calculators & MathSRT Time Shift Tool
Shift SRT cue timestamps by signed milliseconds. Reject shifts that move a cue before time zero.
JSON & DeveloperSSL Certificate Checker
Inspect the verified TLS certificate and validity dates.
DNS & NetworkSSL Certificate Key Matcher
Compare the public key in a PEM certificate with a supplied PEM private key. No network connection is made. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperStandard Deviation Calculator
Calculate population or sample standard deviation.
Calculators & MathSteam ID Converter
Convert account IDs between SteamID64, SteamID3 and SteamID2 for individual public-universe accounts.
JSON & DeveloperStrikethrough and Underline Text
Add combining strikethrough or underline marks to Unicode code points.
Text & WritingString Escaper for Code
Produce a quoted JSON-compatible string literal suitable for JavaScript and common C-family escapes.
Text & WritingString Length Calculator
Measure Unicode code points, UTF-16 units and UTF-8 bytes.
Text & WritingSubnet Calculator
Calculate IPv4 network and broadcast addresses.
DNS & NetworkSubscript and Superscript Generator
Convert supported digits and signs to Unicode superscript or subscript; unsupported characters remain unchanged.
Text & WritingSubtract Days from Date
Subtract calendar days from a date.
Date & TimeSudoku Solver
Solve a 9×9 Sudoku from nine rows of digits, with zero or dot for empty cells. Duplicate clues and unsolvable boards are rejected; search is bounded.
JSON & DeveloperSynthetic User Agent Generator
Generate a Chrome-on-Linux User-Agent template from an entered major version. It is synthetic test data, not a current browser database.
Web & SEOSystemd Service Generator
Generate a service unit for a supplied absolute executable, user and working directory. It does not install or execute the unit.
Web & SEOTemperature Converter
Convert Celsius, Fahrenheit and Kelvin with absolute-zero checks.
Unit ConvertersText Difference Checker
Compare lines and identify additions and removals.
Text & WritingText Joiner
Join newline-separated text chunks using a chosen separator.
Text & WritingText Reverser
Reverse text by Unicode characters.
Text & WritingText Sorter
Sort lines in ascending or descending order.
Text & WritingText Splitter
Split text at a literal delimiter and return an ordered list, retaining empty segments.
Text & WritingText to Binary Converter
Encode UTF-8 bytes as eight-bit binary groups.
Text & WritingText to Hex Converter
Encode text as hexadecimal UTF-8 bytes.
Text & WritingText Wrap and Unwrap
Wrap whitespace-separated words to a chosen width or join wrapped lines. Long words remain intact.
Text & WritingTime Calculator
Add or subtract signed HH:MM:SS durations. Hours may exceed 24; minutes and seconds must be below 60.
Date & TimeTime Converter
Convert seconds, minutes, hours and fixed 24-hour days.
Unit ConvertersTime Duration Calculator
Calculate elapsed seconds between two offset-qualified instants.
Date & TimeTime Format Converter
Convert 24-hour clock input to a 12-hour display.
Date & TimeTimezone Converter
Convert a wall-clock time between IANA zones and flag DST ambiguities.
Date & TimeTip Calculator
Calculate a tip and split a bill evenly among a positive number of people.
Calculators & MathTitle Case Converter
Capitalize words for headings and labels.
Text & WritingTorque Converter
Convert newton-metres, pound-feet and pound-inches.
Unit ConvertersTOTP Code Generator
Generate a six-digit RFC 6238 SHA-1 TOTP using a Base32 secret and entered Unix seconds with a 30-second step. Handle secrets privately. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperTwitter Card Tag Generator
Generate summary_large_image card metadata. Preview and eligibility depend on the social platform.
Web & SEOTwitter/X Card Preview
Extract Twitter card metadata from pasted HTML.
Web & SEOTXT Record Lookup
Read published text records such as SPF policies.
DNS & NetworkTyping Speed Test
Type a supplied passage and measure words per minute at five characters per word and positional accuracy. This interface works locally in your browser.
Text & WritingTypography Unit Converter
Convert CSS pixels, points and inches at 96 pixels per inch.
Unit ConvertersUFW Rule Generator
Generate an allow or deny rule for a TCP or UDP port. It is text output only and never changes this server firewall.
Web & SEOUI Color Palette Builder
Generate primary, light and dark variants and select the higher-contrast black or white text color.
Web & SEOULID Generator
Generate a timestamp-prefixed ULID with 80 cryptographically random bits. IDs generated within one millisecond are not monotonic.
Text & WritingUnix Timestamp Converter
Convert Unix seconds to an ISO UTC instant.
Date & TimeUnix Timestamp Generator
Convert an ISO instant with explicit offset to Unix seconds.
Date & TimeUppercase Converter
Capitalize every letter while preserving punctuation.
Text & WritingUpside Down Text
Flip supported Latin letters with Unicode counterparts and reverse their order.
Text & WritingURL Decoder
Decode a percent-encoded URL component.
JSON & DeveloperURL Encoder
Percent-encode a URL component.
JSON & DeveloperURL Parser
Parse an absolute HTTP or HTTPS URL into its components and query parameter pairs.
JSON & DeveloperURL Slug Validator
Check whether a supplied slug uses lowercase ASCII letters and digits separated by single hyphens.
Web & SEOUser Agent Parser
Extract common browser, operating system and device hints from a supplied User-Agent string. This is a heuristic; strings can be spoofed or reduced.
Web & SEOUTC to Local Time
Display a UTC instant in a specified IANA zone.
Date & TimeUTM Campaign URL Builder
Add campaign source, medium and name parameters to an absolute URL while preserving other parameters.
Web & SEOUTM Parameter Parser
Extract UTM parameters from an absolute URL, preserving duplicate values as lists.
Web & SEOUUID Generator
Generate a cryptographically random version 4 UUID.
JSON & DevelopervCard Generator
Generate a vCard 3.0 contact record with escaped name, organization, email and telephone fields.
Web & SEOVector Distance Calculator
Calculate Euclidean distance and cosine similarity for equal-length finite numeric JSON vectors.
Calculators & MathViewport Checker
Show actual viewport dimensions, display dimensions and device pixel ratio; update after resize. This interface works locally in your browser.
JSON & DeveloperVolume Converter
Convert litres, millilitres, cubic metres and US gallons.
Unit ConvertersVTT to SRT Subtitle Converter
Convert basic WebVTT cues to numbered SRT cues. NOTE, STYLE and REGION blocks are removed; timestamps are validated.
JSON & DeveloperWebP Converter
Encode an uploaded raster image as WebP.
Image & GraphicsWebsite Availability Checker
Check the HTTP response from this server only. Timeouts and blocked targets are reported as errors; this does not establish a global outage.
DNS & NetworkWebsite Response Time Checker
Measure one server-side request, including connection time.
DNS & NetworkWebsite Technology Hints
Inspect HTML and response headers for explicit CMS, library and analytics signatures. Results are hints and can be absent or misleading.
DNS & NetworkWeek Number Calculator
Find the ISO week number and ISO week-year.
Date & TimeWeight Converter
Convert kilograms, grams, pounds and ounces.
Unit ConvertersWhite Screen
Display a full-screen white panel. Exit with Escape or click the panel. This interface works locally in your browser.
Image & GraphicsWord Counter
Count Unicode words and check reading length.
Text & WritingWord Frequency Counter
Count case-insensitive Unicode words and report frequencies in descending order.
Text & WritingWords to Number Converter
Parse English integer words through trillions, including hundred and optional and.
Text & WritingXLSX Sheet to CSV Converter
Convert xl/worksheets/sheet1.xml from an XLSX archive into CSV. Shared strings and sparse cells are supported; formulas are not evaluated and cached values may be stale. Formatting and other sheets are not included. Files are processed temporarily on this server, with an 8 MiB combined upload limit.
JSON & DeveloperXML Comment Remover
Remove XML comments while preserving existing text whitespace. This conservative operation does not collapse mixed-content spaces. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperXML Formatter
Indent valid XML. External entities and document type declarations are rejected; mixed-content whitespace can be normalized. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperXML Plist to JSON Converter
Convert XML-format Apple property lists to JSON. Binary plist files are not supported; DTD declarations are rejected. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperXML Sitemap Generator
Generate a URL sitemap from absolute HTTP(S) URLs.
Web & SEOXML to JSON
Convert XML nodes, attributes and text into JSON.
JSON & DeveloperXML Validator
Validate XML syntax and optionally a self-contained XSD. External entities, XSD includes and imports are blocked. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperYAML to JSON Converter
Parse YAML with object creation disabled and emit JSON. Custom tags and invalid mappings are rejected. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperYAML Validator and Formatter
Validate YAML using Symfony and emit normalized YAML. Object deserialization and custom tags are disabled. This tool processes bounded inputs on this server without retaining submitted content.
JSON & DeveloperYouTube Timestamp Link Generator
Generate a YouTube URL with an entered start time in whole seconds.
Web & SEOYouTube Video ID Extractor
Extract an eleven-character video ID from supported youtube.com and youtu.be URL formats.
Web & SEOZalgo Text Generator
Add a bounded number of Unicode combining marks to each character.
Text & WritingZIP File Creator
Create a ZIP archive from selected files, using safe basenames and rejecting duplicate names. Files are processed temporarily on this server, with an 8 MiB combined upload limit.
JSON & DeveloperZIP File Extractor
Read ZIP entries and provide individual downloads. Reject encrypted entries, unsafe names, excessive expansion, more than 100 files or more than 10 MiB extracted data. Files are processed temporarily on this server, with an 8 MiB combined upload limit.
JSON & Developer