Calculate Text Entropy
Measure the Shannon entropy of the text in bits per character. Runs entirely in your browser, so your data never leaves your device.
0 chars · 0 lines
Output
The result appears here as you type.
How to use Calculate Text Entropy
- 1. Paste your text. Enter any string into the input pane, from a single word to a full passage. The calculation looks at the frequency distribution of every character present.
- 2. Read the entropy value. There are no settings to adjust. The output is the Shannon entropy in bits per character: higher values mean a more even, less predictable mix of characters, while lower values mean heavy repetition.
- 3. Compare against other samples. Run different strings through the tool and compare their entropy values side by side to judge which one has a more uniform or more skewed character distribution.
When to use Calculate Text Entropy
Calculate Text Entropy measures the Shannon entropy of a string in bits per character, a number that captures how predictable or varied its character distribution is. Reach for it when you need an objective measure of randomness rather than a visual guess.
- Estimating password strength. You want a rough sense of how random a candidate password's characters are beyond just its length. Higher entropy per character suggests a less predictable, harder-to-guess string.
- Comparing generated versus natural text. You're checking whether a block of text looks machine-generated or repetitive. Natural language typically sits in a known entropy range per character, so an unusually low or high value is a signal.
- Teaching information theory concepts. A course on information theory needs a concrete example of Shannon entropy applied to text. Feed in simple strings like all-repeated characters versus varied ones to show the entropy difference.
Examples
Entropy of a two-symbol string
Input
aabb
Output
1.0000
About the Calculate Text Entropy tool
Calculate Text Entropy does its work locally, right in the browser. Measure the Shannon entropy of the text in bits per character. There is no upload step, no queue and no account, and your data never travels over the network.
It belongs to the Text Tools collection on EditSafely, a set of 211 small, focused Text utilities that share the same instant, private workspace.
There is nothing to configure. Provide the input and the result appears on its own. A worked example further down the page shows exactly what the tool produces for a real input.
Running locally also makes the tool fast and dependable: results appear as you type or drop a file, there is no server outage that can take it down mid-task, and confidential data can be processed without a second thought.
Frequently asked questions
Is Calculate Text Entropy free to use?
Yes, it is completely free. All 2,658 tools on EditSafely work without an account, a subscription or usage limits.
Is it safe to paste sensitive or confidential data?
Everything happens locally. Your browser downloads the tool's code once, then does all the processing itself; nothing you enter is transmitted, stored or logged. You can even go offline after the page loads and it will still work.
How much text can I process at once?
There is no fixed limit. Because the work happens on your own device rather than on a shared server, the practical ceiling is your machine's memory, which comfortably handles inputs far larger than typical online tools allow.
Do I need to sign up or install anything?
No. The tool works in any modern browser on desktop, tablet or phone. There is no account to create, no extension to add and no software to install.
How do I use the result?
The output panel has a one-click copy button, and you can keep refining the input while you work; the result updates in place as you type.