Entropy Meter
Measures the Shannon entropy of a string or file and shows a byte histogram — useful for spotting keys.
Shannon entropy per byte tells you how compressible a sequence is, and that one number separates plain text from compressed data from encrypted data surprisingly reliably. It is how you tell whether a blob in a file is a key, a picture, or padding.
Drop a file
Or paste text below. Analysed in your browser.
Everything is measured in your browser; no file or text is uploaded.
How to use it
Paste a string or drop a file
Both give bits per byte plus a histogram of byte values. The histogram is often more informative than the number.
Read against the usual bands
English text sits near 4 bits per byte, source code a little higher, a compressed or encrypted stream at 7.9 and above. A flat histogram at 8.0 is either encryption or a random key.
Use it as a filter, not a verdict
High entropy narrows a large file down to the few regions worth reading. What those regions are still has to be established by looking at them.
Common questions
Does high entropy mean the file is encrypted?
No. Compressed archives, JPEGs, PNGs and video are all near-maximum entropy, because compression is what removes the redundancy entropy measures. The measure cannot distinguish a zip from a ciphertext.
Does low entropy mean the data is weak?
For a key, low entropy is a real problem. For a password, this measure is the wrong tool entirely: `abababababab` scores low and `Tr0ub4dor&3` scores high, and both are weak for reasons entropy per byte cannot see. Use the strength meter.
Is the file uploaded?
No. The bytes are counted in your browser and the histogram drawn there.
Feed it from
Password Strength Meter
Estimates how long a password would take to crack, naming the patterns that weaken it.
Passphrase Generator
Builds a diceware-style passphrase from a word list, showing the entropy in bits.
Secret Scanner
Scans pasted code, logs or a config dump for API keys, tokens and private keys, with entropy heuristics.
Hash Identifier
Guesses which algorithm produced a hash from its length, charset and prefix, ranked by likelihood.
Next
These accept what this tool produces, so the result can go straight in.
Hash Identifier
Guesses which algorithm produced a hash from its length, charset and prefix, ranked by likelihood.
Hex Viewer
Shows any file as an offset/hex/ASCII dump, identifies the magic bytes and highlights a search hit.
Password Strength Meter
Estimates how long a password would take to crack, naming the patterns that weaken it.
Secret Scanner
Scans pasted code, logs or a config dump for API keys, tokens and private keys, with entropy heuristics.
Background Remover
Keys out a flat or single-colour background in OKLab and returns a transparent PNG, with a brush for fixing the edges.
Colour Picker
Picks a colour on an OKLCH field, with a screen eyedropper or from an uploaded image, and copies it in any notation.