Skip to content
Runs privately in your browser

Free Online Password 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.

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

Result



How to use Password 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.
  1. Set Text.
  2. Run the tool, review the result and its stated limitations, then copy or download if needed.
Example & practical use
Estimate a character-pool upper bound assuming independent uniform character selection. Human-chosen passwords can have much less entropy; no crack time is claimed. The example below demonstrates Text.
Example input:
{
  "text": "abCD12!"
}
Expected result (relevant fields):
{
  "length": 7,
  "pool": 94
}
Features & result limitations
Estimate a character-pool upper bound assuming independent uniform character selection. Human-chosen passwords can have much less entropy; no crack time is claimed.
Frequently asked questions
What inputs does Password Entropy Estimator accept?
Text
How should I interpret the Password Entropy Estimator result?
Estimate a character-pool upper bound assuming independent uniform character selection. Human-chosen passwords can have much less entropy; no crack time is claimed.
Where does Password Entropy Estimator 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.