Question 1

What is a checksum?

Accepted Answer

A checksum is a fingerprint of a file's bytes. If the file changes at all, the checksum changes — so it proves a copy or delivery is intact and unaltered.

Question 2

Does my file upload anywhere?

Accepted Answer

No. Everything is hashed locally in your browser with WebAssembly — files never leave your device. You can confirm it in your browser's network tab.

Question 3

Which algorithm should I use?

Accepted Answer

xxHash64 for fast media verification (the default), MD5 if a client requires it, SHA-256 for security-grade integrity, CRC-32 for a quick check.

Question 4

What is MHL?

Accepted Answer

MHL (Media Hash List) is the standard XML manifest for camera offload and delivery. This tool exports classic MHL v1.1 and can verify files against an MHL.

Question 5

Can I verify a whole folder?

Accepted Answer

Yes. Choose a folder (or drag one in) and every file is checksummed recursively — built for entire card and delivery folders, including multi-GB files.

Question 6

Is it free?

Accepted Answer

Completely free, no sign-up and no upload — it runs entirely in your browser.

Checksum verifier for media files

What is a checksum?

How to use it

Algorithm guidance

What is MHL?

Frequently asked questions