What this tool does
A hash function turns any input into a fixed-length “fingerprint.” The same input always produces the same hash, and even a tiny change produces a completely different one. This makes hashes ideal for verifying file integrity — confirming a download was not corrupted or tampered with — and for checksums. This tool uses your browser’s built-in Web Crypto API.
Example
The SHA-256 hash of the text hello is:
2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
Paste the same text and you will get exactly that value every time.
How to verify a download
- Download the file and its published checksum (often a
.sha256file or a value on the download page). - Choose the matching algorithm above and select your downloaded file.
- Paste the published checksum into the Compare box. A green match means the file is intact.
About SHA-1 and MD5
SHA-1 is included for compatibility and educational purposes only. It is considered broken for security because collisions can be produced. MD5 is weaker still. Use SHA-256 or stronger for anything security-related.
Limitations
- A matching hash confirms the file is identical to the source of the checksum — it does not prove that source is trustworthy.
- Very large files are read into memory in the browser, so extremely large files may be slow or fail on low-memory devices.
- Hashes are one-way: you cannot recover the original input from a hash.
How to fix common problems
- Checksum doesn’t match: make sure you selected the same algorithm the publisher used, and that the download completed fully. Re-download if needed.
- Different hash than another tool: confirm both tools hash the raw bytes (not, say, the text with a trailing newline added).
Privacy: Files and text are hashed entirely in your browser. Nothing is uploaded to any server.