Entropy Calculator
Calculate the Shannon entropy of text or a file in bits per byte, see the entropy block by block, and learn whether data looks compressed or encrypted.
Input
Stays in your browserShortcuts: Ctrl+Enter run · Ctrl+Shift+C copy result · / search (use ⌘ on Mac)
Next steps
Done here? Use the Send to… menu on the result to carry it on to Hex Dump.
Free Online Entropy Calculator
Entropy tells how random data looks. Repeated text is close to 0, ordinary text is around 4 and compressed or encrypted data is close to 8 bits per byte. It gives developers a quick browser-based way to solve a focused entropy calculator task before moving the result into a project.
How to use Entropy Calculator
Type or paste text, or open a file, and press Calculate. For files you also get the entropy of each block, which shows where the random-looking parts are.
Common mistakes
- Judging a short text: a few characters give a low score even when they are random.
- Reading a high score as proof of encryption: compressed data scores the same.
Frequently asked questions
What is Shannon entropy?
It measures how unpredictable data is, in bits per byte from 0 to 8. All the same byte gives 0. Every byte value equally likely gives 8.
Does high entropy mean a file is encrypted?
It means it looks random. Compressed files (ZIP, JPEG, MP4) also score close to 8, so entropy alone cannot tell compressed from encrypted.
Is entropy the same as password strength?
No. This measures the bytes you give it, not how hard a password is to guess. A long random password has a high score, but so does a short one with all different letters.
Is my file uploaded?
No. The calculation runs in your browser.
How do I use this entropy calculator tool?
Use the interactive controls above; processing stays in your browser and the result is intended as a practical starting point for development work.
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