Hash & UUID generator
Calculate hashes of text or files and generate UUIDs. Everything happens inside this browser; files and results are never sent to a server or saved.
Calculate hashes
Results
MD5 has known collisions and must not be used for security purposes such as signatures or password storage. Use it only as a checksum to check that a file is not corrupted.
Generate UUIDs
Guide
Limits
- Files up to 100MB and text up to 1,000,000 characters are supported.
- Large files show progress while being read, and reading can be cancelled. The SHA step is handled by the browser in one go, so it cannot be cancelled once it starts; wait until it finishes.
- Hash comparison ignores spaces, colons, a 0x prefix and letter case, and picks the algorithm from the value length.
- You can generate 1 to 100 UUIDs at a time.
FAQ
Are files sent to a server?
No. The browser reads the file and calculates the hashes on this device only; nothing is uploaded or saved.
How do UUID v4 and v7 differ?
v4 is almost entirely random. v7 starts with a millisecond creation time, so values sort in creation order, which suits database keys. Order is preserved even when several are created in the same millisecond.
Does a v7 UUID reveal when it was created?
Yes. The first 12 hex digits of a v7 UUID are the creation time in milliseconds, so use it only where exposing the time is fine. For tokens that must be hard to guess, use v4 or a dedicated security token.
Why is MD5 shown separately?
Many download pages publish only MD5, so it is shown for file verification. Collision attacks are possible, so use SHA-256 or stronger for security.