How to calculate a hash
- Type or paste some text, or choose a file from your device.
- All five hashes appear instantly. Click “Copy” on the one you need.
- To verify a download, paste the hash published by the author into the comparison box.
- If it matches, it's highlighted in green and you know the content is identical.
What is a hash
A hash is a “digital fingerprint” of a text or file: a fixed-length string that changes completely if even a single character is modified. The same content always gives the same hash.
It's used to check that a downloaded file wasn't corrupted or tampered with, by comparing its hash with the one the author publishes, and to detect duplicates.
MD5 and SHA-1 are considered weak for security (collisions can be crafted): they're fine for checking integrity, not for protecting passwords. For security uses, prefer SHA-256 or SHA-512.
Things to keep in mind
- A hash isn't encryption and can't be “undone”. On its own it isn't suitable for storing passwords either.
- Text is processed as UTF-8. The same text with a different line-break format gives a different hash.
- Large files (up to 500 MB) are read into memory in full, so they can be slow or fail on devices with little memory.
Frequently asked questions
Is my file uploaded to a server?
No. The hash is calculated in your browser and the file never leaves your device.
How do I verify a downloaded file?
Calculate its hash, paste the hash published by the author into the comparison box and see if it matches.
Which algorithm should I use?
Any of them works for checking integrity, but SHA-256 is the most recommended. MD5 and SHA-1 are no longer safe against attacks.
Can a hash be reversed to get the text back?
No. A hash is a one-way function: you can only check whether some content produces that hash.
Is it free?
Yes, it's free, needs no sign-up and works right in your browser.