How to calculate a file checksum
- Click the box and choose one or more files, or drag them onto it.
- Tick the algorithms you need. SHA-256 is ticked by default.
- Wait for the progress bar. Each file gets its own card with one line per algorithm.
- To check a download, paste the checksum from the download page into the compare box. The tool says whether it matches.
- Use Copy on a line, Copy all, or Download .txt to keep the results.
Which algorithm to pick
| Algorithm | Length | Good for |
|---|---|---|
| MD5 | 32 characters | Spotting accidental damage when a site only publishes MD5. Not safe against deliberate tampering. |
| SHA-1 | 40 characters | Older projects and Git style checks. Also not safe against deliberate tampering. |
| SHA-256 | 64 characters | The usual choice for downloads and software releases. |
| SHA-512 | 128 characters | Extra long hash. Limited to files up to 512 MB here. |
Tips for better results
- Use the algorithm the download page lists. If it lists several, SHA-256 is a good pick.
- Letter case does not matter. The tool compares the values in lowercase.
- You can paste a whole line such as hash plus file name. The tool picks out the checksum itself.
- Take the expected checksum from the official page over HTTPS, not from the same mirror that hosts the file.
- If the result does not match, download the file again before you worry about anything else.
Limits to know about
- A matching checksum shows the file is identical to the one the publisher hashed. It does not show the file is safe, and it does not scan for malware.
- SHA-512 reads the whole file into memory, so it is skipped for files over 512 MB. MD5, SHA-1 and SHA-256 are read in pieces and have no size limit set by the tool.
- Speed depends on your device. Very large files can take a minute or more, and the tab must stay open.
- You can select files, not folders.
- MD5 and SHA-1 are broken for security use. Two different files can be made to share a hash.
Privacy
Your files are read in your browser and hashed there, piece by piece. Nothing is uploaded to our server or to any other service.
Frequently asked questions
What is a checksum?
It is a short fingerprint calculated from the exact bytes of a file. If even one byte changes, the fingerprint changes completely.
Which algorithm should I use?
Use the one the publisher gives you. If you have a choice, pick SHA-256.
Why does my checksum not match?
Common reasons are an incomplete download, a different version of the file, a different algorithm, or a file that was edited after download. Download it again and compare once more.
Is MD5 still useful?
Only for catching accidental errors. Do not rely on it to prove a file was not tampered with.
Can I hash text instead of a file?
Use the Hash Generator for text. This tool is for files.
How big a file can I check?
There is no fixed limit for MD5, SHA-1 and SHA-256. Your device memory and patience are the limit. SHA-512 stops at 512 MB.
About this tool
ToolsRiver File Checksum Calculator is free and needs no sign up. The hashing code runs in your browser and was checked against known test values.