Free tool
Check a file's SHA-256 hash
Add any file to see its SHA-256, SHA-512, SHA-1 and MD5 hashes. Paste the checksum from a download page, and the tool says if your file matches. Add 2 or more files to see which ones are identical. It reads files of any size, also several GB, and nothing is uploaded.
Runs on this device. Your files are not uploaded.
Drop files here
Any file, of any size. Add as many as you want. They stay on this device.
Any file, of any size. Add as many as you want. They stay on this device.
How it works
- Read. A background worker in your browser reads the file in parts of 8 MB, so a file of several GB needs little memory. The page shows how far it is.
- Hash. Each part goes through MD5, SHA-1, SHA-256 and SHA-512 at the same time, so the file is read once.
- Compare. With one pasted checksum, the tool compares it with the hash of the same length. With a list, it finds the line with the file's name and compares only that line. With 2 or more files, it compares their SHA-512 hashes to find files that are the same.
Hash lengths
| Method | Hex characters | Use it to |
|---|---|---|
| SHA-256 | 64 | Check downloads and backups |
| SHA-512 | 128 | Check downloads and backups |
| SHA-1 | 40 | Catch damage only, on older pages |
| MD5 | 32 | Catch damage only, on older pages |
To lock a file with a passphrase before you send it, use the file encryption tool.
Questions people ask
Does this tool upload my files?
No. Your browser reads each file on your device and works out the hashes there. No file, file name or hash goes to our server or to anyone else. To check, load this page, turn off Wi-Fi, and add a file. The tool still works, also with a file of several GB.
What is a file hash, or checksum?
A hash is a short code that a fixed method works out from every byte of a file. The same file always gives the same hash. A change of one bit gives a completely different hash. So when a download page lists a SHA-256 checksum, a matching hash shows that your copy is the same file, with no damage and no changes on the way.
Which hash should I use: SHA-256, SHA-1 or MD5?
Use SHA-256 or SHA-512. Researchers made two different PDF files with the same SHA-1 hash in 2017, and MD5 collisions have been easy to make for years. So MD5 and SHA-1 still catch damage, but not a planned change. NIST will retire SHA-1 by December 31, 2030. The tool shows all 4, because older download pages still list MD5 or SHA-1, and it marks a match on them as weak.
How do I check a hash on Mac, Windows or Linux?
On a Mac, open Terminal and type shasum -a 256 followed by the file path. On Windows, open PowerShell and type Get-FileHash followed by the file path. It uses SHA-256 if you do not choose another method. On Linux, type sha256sum followed by the file path. This page gives the same results with no commands.
How do I check that a copy or a backup is the same as the original?
Add both files. When the hashes match, the tool says the files are identical. That works for a photo you exported and its original, a backup on a USB drive, or two downloads of the same file. File names and dates do not count, only the bytes in the file.
Can I paste a SHA256SUMS file?
Yes. Paste the whole list, with one checksum and one file name per line, in the sha256sum, shasum --tag or name: checksum form. The tool checks each file only against the line with its own name, and says which line matched. A file whose hash is on the line for another name does not match. A list that gives one name 2 different hashes is refused.
Sources
- FIPS 180-4: Secure Hash Standard (NIST) · checked Oct 9, 2026
- NIST retires SHA-1 cryptographic algorithm (NIST, December 2022) · checked Oct 9, 2026
- SHAttered: the first SHA-1 collision (CWI Amsterdam and Google) · checked Oct 9, 2026
- Get-FileHash (Microsoft Learn, PowerShell) · checked Oct 9, 2026
Open source code in this tool
- hash-wasm 4.12.0, MIT. MD5, SHA-1, SHA-256 and SHA-512, run in a background worker
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