Shannon Entropy Calculator
Calculate Shannon entropy of text to estimate how random or predictable it is. Useful for security and data analysis. Runs locally in your browser.
Input
Output
Tip: You can verify in DevTools → Network that nothing is uploaded.
About this Shannon Entropy Calculator
Shannon Entropy measures the uncertainty of a string based on character frequency. Lower entropy indicates more repetition; higher entropy indicates more randomness.
This is useful for spotting compressed/encoded data, evaluating token randomness, and quick security analysis. It is a statistical measure, not a guarantee of security.
- Process text data quickly without external tools
- Transform content for development workflows
- Clean and format text for analysis
- Enable Auto to transform as you type
- Upload text files directly from your device
- Download the result when done
FAQ
No. Everything runs locally in your browser. Nothing you paste is sent to a server.
After the page loads once, it will typically keep working offline (unless you hard refresh with no cache).
No. Your input stays in your browser. Only optional preferences like theme or language may be stored.
Any plain text. You can paste text directly into the input box.
Higher entropy generally means the text is more random and less predictable.
It can be a signal, but entropy alone is not a full strength assessment. Use it as one metric only.
If characters repeat heavily, the distribution is predictable, lowering entropy.