Find Entropy of a Number

Find Entropy of a Number lets you analyze the randomness in a number by computing its Shannon entropy. It breaks down digit frequency, handles optional cleanup, and gives you the result instantly. You can toggle display options, include frequencies, and control formatting all in your browser, no uploads required.

Paste your input above or import a file below.
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Supported file types: .txt, .csv, .tsv, .log, .json, .xml, .md, .ini, .yaml, .yml, .html, .htm, .css
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Options
Ignore non-digits
Show digit frequencies
Round to 4 decimals

How to Use:

Paste or type your numeric data into the input box on the left. Each digit will be counted and used to calculate the entropy. You can also import a text file using the Choose File button, supporting formats like .txt, .csv, and .json.

Then open the Options box to customize the calculation:

  • Ignore non-digits strips out anything that isn’t a 0–9 digit
  • Show digit frequencies will display how often each digit appears
  • Round to 4 decimals cleans up the final entropy value for easier reading

As soon as you make a change, the tool updates the result with a blue border flash. You can copy the result, export it to a file, or clear everything using the buttons below the output box.

What Find Entropy of a Number can do:

This tool takes a numeric input and calculates its Shannon entropy based on the distribution of digits. The more evenly distributed the digits, the higher the entropy. You can also see a frequency breakdown if you want to inspect the distribution in more detail.

Everything updates live and runs entirely in the browser. The output counter tracks the length of the final result, and toggles let you tweak precision and formatting. Whether you’re working with a single value or importing long sequences, the tool adapts instantly.

Example:

Input:

11235813213455

Output (with frequencies shown):

Frequencies:
1: 4
2: 2
3: 3
4: 2
5: 2
8: 1

Shannon Entropy: 2.4591

Common Use Cases:

Find Entropy of a Number is great for checking how uniform a number sequence is. Whether you’re analyzing generated values, testing numeric randomness, or exploring frequency distributions, this tool gives you fast insight with full control over formatting and display. It’s especially helpful for math, data compression, or cryptography projects where digit spread matters.

Useful Tools & Suggestions:

For more ways to poke at number structure, check out Change Number’s Mantissa it lets you alter the significant digits directly. You could also try Generate Deficient Number Sequence if you’re exploring how number properties vary across sets.

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