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Free Online Readability Score Calculator

Estimate Flesch reading ease, Flesch-Kincaid grade and Gunning Fog using an English vowel-group syllable heuristic.

Your input stays on this device. Processing is bounded; regex runs in a worker with a two-second timeout.

Result



How to use Readability Score Calculator
Estimate Flesch reading ease, Flesch-Kincaid grade and Gunning Fog using an English vowel-group syllable heuristic.
  1. Set Text.
  2. Run the tool, review the result and its stated limitations, then copy or download if needed.
Example & practical use
Estimate Flesch reading ease, Flesch-Kincaid grade and Gunning Fog using an English vowel-group syllable heuristic. The example below demonstrates Text.
Example input:
{
  "text": "The cat sat."
}
Expected result (relevant fields):
{
  "words": 3,
  "sentences": 1,
  "syllables": 3
}
Features & result limitations
Estimate Flesch reading ease, Flesch-Kincaid grade and Gunning Fog using an English vowel-group syllable heuristic.
Frequently asked questions
What inputs does Readability Score Calculator accept?
Text
How should I interpret the Readability Score Calculator result?
Estimate Flesch reading ease, Flesch-Kincaid grade and Gunning Fog using an English vowel-group syllable heuristic.
Where does Readability Score Calculator process my data?
Inputs are processed locally in your browser. Submitted text is not sent to external services. A successful-run event increments an aggregate tool counter without your input.