What is UUID?
A plain-English definition, and the tools that work with it.
A UUID (Universally Unique Identifier) is a 128-bit value (written as 36 characters like 550e8400-e29b-41d4-a716-446655440000) designed to be unique across space and time without a central authority. Developers use it as an ID that won't collide even when generated on different machines.
- UUIDs are generated independently yet are practically guaranteed not to clash, so systems can create IDs offline.
- Version 4 (random) is the most common. Other versions embed a timestamp or namespace.
- They're great as database keys and file names when you can't rely on a sequential counter.
Tools for UUID
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UUID Generator
Generate secure UUIDs instantly, random v4, time-ordered v7, or the nil UUID. Bulk-generate up to 1,000, copy or export as TXT/CSV, all in your browser.
NanoID Generator
Generate secure, URL-safe Nano IDs in your browser with a live size slider, alphabet presets, a custom alphabet, bulk output up to 1,000 and a real-time collision-odds estimate. Nothing is uploaded.
Hash Generator
Compute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 checksums of any text or file at once, generate HMAC signatures with your own key, and verify a download against its expected hash, all in your browser, nothing uploaded.
Password Generator
Generate strong, crypto-secure passwords and memorable passphrases in your browser: control length, character sets, look-alikes and guaranteed classes, with a live entropy meter. Nothing is uploaded.
Frequently asked questions
Related terms
- Base64Base64 is a way of encoding binary data (like an image or file) into plain ASCII text using 64 safe characters. It lets you embed or transmit binary content through systems that only handle text, such as email, JSON or data URIs.
- JSONJSON (JavaScript Object Notation) is a lightweight, text-based format for structured data, built from key–value pairs and lists. It's the standard way apps and APIs exchange data because it's easy for both humans and machines to read.
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