Hash Check: File Checksum Tool

Hash Check is a hash checker for files you've downloaded. Choose the file, paste the checksum from the download page, and the app tells you in green or red whether they match. It uses SHA256 unless the hash you paste is a different length. Your file is read on your phone and never uploaded.

It's for the files where a bad copy hurts: a Linux ISO you're about to write to a USB stick, an APK or a firmware image from outside the Play Store, a backup you moved off your PC.

WHAT IT DOES
• Hashing starts as soon as you choose a file. There's no button to press.
• Six algorithms: MD5, SHA1, SHA224, SHA256, SHA384 and SHA512
• The algorithm follows what you paste. A 32 character hash switches it to MD5, a 64 character one to SHA256.
• Paste the hash however you got it: upper or lower case, split up by spaces or colons, a line of sha256sum, shasum or certutil output, or the table PowerShell prints
• Paste a whole SHA256SUMS list and it picks the line with your file's name
• Big files get a progress bar that shows how much has been read (1.9 GB of 4.4 GB, say), and you can cancel at any point
• Copy the result, or share it as one line, SHA256 (file name) = hash, the format sha256sum and shasum can verify
• Share a file to Hash Check from your file manager and it opens with that file loaded. Share text that contains a hash and it goes straight into the expected field.
• To compare two copies of a file, put the first one's hash in the expected field and then choose the second file. The expected hash stays where it is.

Rotating the phone or switching apps doesn't interrupt a check. Android sometimes closes apps in the background, and when it closes this one, the file hash calculation starts again when you return.

WHAT IT DOESN'T DO
It's a file hash checker and works on one file at a time. You can't hash a piece of text or a whole folder, and the six algorithms above are all it has, so CRC32, SHA3 and BLAKE2 aren't included.

A NOTE ON MD5 AND SHA1
Both are fine for spotting a corrupted download. Both also have known collision attacks, so don't rely on them alone against deliberate tampering. When the site lists a SHA256 or SHA512 checksum as well, use that one. And a match only proves your file is the one the hash was made from, so take the hash from the project's own site.

PRICE AND PRIVACY
This hash checker is free, with one banner ad at the bottom of the screen. There are no in app purchases and no account. The app has no server of its own, and the internet permission is there for the ad. Checking a file stored on your phone works without a connection. If you're in Europe, the app asks for ad consent on first launch, and Privacy options in the menu lets you change your answer later.

Runs on Android 6.0 and newer.

QUESTIONS
Where do I find the hash to compare against? On the download page, usually next to the download link, or in a file called SHA256SUMS or one ending in .sha256.
What does a mismatch mean? Usually a download that broke off or got corrupted. Download it again and check once more. If it still doesn't match, you may have the wrong file or the wrong hash.

A checksum format that won't paste, or a result that looks wrong? Email me at filipnordquist@protonmail.com with the text you pasted and I'll look into it.