Seal a freshly downloaded folder with a checksum file.
Re-check a copy against its checksum file, file by file.
Diff two checksum files — no folders needed.
Copying large amounts of video and audio to USB sticks — especially across many sticks for distribution — carries a real risk of silent corruption: a bit flips, a copy gets interrupted, a stick has a bad sector. Media players usually don't warn you; a corrupted file can look completely normal in a file browser and only fail when someone plays it in front of an audience.
MediaCheck creates a small checksum file — a list of SHA-256 fingerprints, one per file — right after you download or receive a set of media. Later, after copying that media anywhere else, you re-run MediaCheck against the copy and it tells you, file by file, whether anything changed.
No. MediaCheck runs entirely inside your browser and never makes a network request. All hashing happens locally on your computer.
Right next to the folder it describes, so that if the folder is copied to a USB stick or another drive, the checksum file travels with it and can be used to verify the copy later.
Yes — Verify simply reports those as missing or extra files rather than failing outright, so you can judge whether that's expected or a real problem.
Any modern browser works for hashing and reporting. Browsers with the newer "save file" dialog (current Chrome and Edge) let you choose exactly where the checksum file is saved; other browsers fall back to downloading it, after which you move it next to the media folder yourself.
Yes, entirely free with no account required. Support is optional.
No account, no subscription, no hidden costs. If this tool saved your AV team from a corrupted stick, you can support the project with a small donation.
☕ Support the projectEntirely optional — every feature stays free.
.sha256 file). MediaCheck re-hashes every file and tells you if anything changed.