UUID & Hash Generator
Generate UUIDs and compute MD5, SHA-1, SHA-256 or SHA-512 hashes.
UUID v4 generator
Hash calculator
…or drop a file here
Hashed in your browser, never uploaded.
About this tool
The UUID generator produces version 4 UUIDs (122 bits of cryptographically secure
randomness) using your browser's own crypto.randomUUID(). Generate one at a
time or up to 1,000 in bulk.
The hash calculator computes MD5, SHA-1, SHA-256 and SHA-512 digests of typed text or a dropped file. Text uses the native Web Crypto API (plus a small JavaScript MD5); files are streamed through incremental hashers in slices, so verifying a multi-gigabyte download works with a progress readout. Everything runs on your device, so nothing is uploaded and the page works offline.
Frequently asked questions
- Are the UUIDs generated here truly random?
- Yes. They come from your browser's built-in crypto.randomUUID(), which uses a cryptographically secure random number generator.
- Which hash should I use?
- SHA-256 is the safe default. MD5 and SHA-1 are cryptographically broken; only use them when an older system requires them.
- Can I hash a large file without uploading it?
- Yes. Files are read in small slices and hashed locally, so nothing is uploaded and even multi-gigabyte files work without exhausting memory.
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