How to use the Checksum Calculator
- Paste the expected checksum (optional) — for example from a software download page.
- Drop the file.
- Compare: a green “Match” badge means the file is identical.
Why verify a checksum?
A checksum is a fingerprint of a file. If even one byte changes — from a corrupted download, a damaged drive or tampering — the hash changes completely. Software publishers list SHA‑256 hashes so you can confirm you have the genuine file.
| Algorithm | Use today |
|---|---|
| MD5 | Quick integrity checks only; not secure against deliberate tampering. |
| SHA‑1 | Legacy; avoid for security. |
| SHA‑256 | The standard choice for verifying downloads. |
| SHA‑512 | Even longer hash; also secure. |
MD5 and SHA‑256 work for files of any size (streamed). SHA‑1 and SHA‑512 are calculated for files under 1 GB.
Frequently asked questions
Why don’t my hashes match?
Either the file is different from the one the publisher hashed (wrong version, incomplete download or corruption), or you are comparing different algorithms. Check that you used the same algorithm, then download the file again.
Can I hash very large files?
Yes. MD5 and SHA-256 are computed in streaming chunks, so even multi-gigabyte ISO images work. It may take a minute for very large files.
Does Sendryo check file integrity during transfers?
Yes. WebRTC data channels use reliable, ordered delivery over an encrypted connection, and the receiver checks that the received size matches. For extra assurance, compare SHA-256 hashes on both devices with this tool.