# File Checksum — Check SHA-256 and MD5 checksums on Mac

Verify downloads with SHA-256, SHA-512, SHA-1 or MD5 hashes. Part of OneMacTools, 151 private tools in one native Mac app (macOS 26 or later); category: Files. Runs on your Mac; nothing is uploaded.

Calculate checksums for files of any size and compare them with the one published by the download site, so you know the file wasn't corrupted or tampered with.

Page: https://www.onemactools.com/tools/file-checksum · Download: https://www.onemactools.com/download · Pricing: https://www.onemactools.com/pricing

## How to use it
1. **Drop your files.** Drag in a download, installer or backup file. Or select it in Finder, right-click and choose Quick Actions › OMT: Copy SHA-256 Checksum.
2. **Choose the algorithm.** Pick the one the download site uses, most often SHA-256.
3. **Paste the expected hash.** If the site publishes a checksum, paste it into Compare with to check it automatically.
4. **Click Calculate.** Each file is read in full and its checksum worked out. Files of any size work.
5. **Read the result.** The checksums are copied to the clipboard and saved in a text file in a new dated folder in Downloads › OneMacTools. If you pasted a hash, you're told whether it matches.

## Options
- **Algorithm:** SHA-256 (the default), SHA-512, SHA-1 or MD5. Use whichever the site publishes. SHA-256 and SHA-512 are the ones to trust; MD5 and SHA-1 are fine for spotting corruption but not for security.
- **Compare with:** Optional. Paste the hash the site publishes. Spaces and capital letters don't matter. If none of your files match it, you get a clear mismatch error.
- **Copy result to clipboard:** On by default. Copies each checksum with its file name to the clipboard, ready to paste.

## Tips
- Paste the expected hash into Compare with rather than comparing by eye. A single wrong character means the file is different.
- Paste only the hash itself, not the file name or a label such as “SHA256:” in front of it.
- A mismatch usually means the download was cut short or corrupted. Download it again before opening it.
- To check a backup copied correctly, calculate checksums of the original and the copy. If they match, the files are identical.
- The saved text file uses the same layout as the shasum command, so you can keep it alongside your files as a record.

## Questions
**How do I check a SHA-256 checksum on a Mac?**
Drop the file onto File Checksum, leave SHA-256 selected, paste the published hash into Compare with and click Calculate. You'll be told whether it matches.

**How do I check an MD5 hash on a Mac?**
Choose MD5 as the algorithm, drop the file and click Calculate. Paste the expected MD5 into Compare with to check it automatically.

**What does it mean if the checksum doesn't match?**
The file isn't the same as the one the site published. It was probably corrupted or cut short while downloading, so download it again. Don't open it if it's an installer.

**Which algorithm should I use?**
The one the download site lists. If you can choose, use SHA-256: it's the most widely published and is secure.

**Can I check if two files are identical?**
Yes. Drop both and compare their checksums in the result. Identical checksums mean the contents are identical.

**Can I check several files at once?**
Yes. Drop them together and each gets its own line. With a hash in Compare with, it passes if any of the files matches.