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UUID / ULID / NanoID / Token Generator

A UUID is ready the moment the page opens. Switch to UUID v7, ULID, NanoID or a random token, generate up to 10,000 at once and save them as .txt, .csv or .json. Paste an existing UUID or ULID to read its embedded time and version.

On-device・No upload

Your files and input are processed only inside your browser on this device and are never uploaded to our servers.

The most common UUID: 122 fully random bits. Order carries no meaning.

Latest ID 
Options
Letter case

1–10,000

How to use

  1. Pick UUID v4, UUID v7, ULID, NanoID or Random token at the top. A UUID v4 is generated as soon as the page loads.

  2. Adjust case, hyphens, alphabet or length under “Options”. Changes regenerate automatically.

  3. Set “How many” (1–10,000) and press “Regenerate” for fresh values.

  4. Copy the featured ID, use “Copy all”, or save the batch as .txt, .csv or .json.

  5. To examine an existing ID, choose “Inspect ID” and paste a UUID or ULID.

What it does

Monotonic UUID v7 and ULID

IDs generated within the same millisecond stay in order: the random part is incremented (RFC 9562 method 2). You get bulk, index-friendly, time-ordered keys ready for a database.

Unbiased randomness

Every value comes from the browser’s cryptographic RNG (crypto.getRandomValues), and characters are drawn with rejection sampling — no modulo bias, even for custom alphabets.

Collision odds on the spot

From the number of random bits we show how many IDs it takes to reach a 1% collision chance and the chance of a duplicate within the batch you just generated — a solid basis for choosing NanoID length.

UUID & ULID inspector

Detects the version and variant of a pasted UUID and shows the embedded time of v1, v6 and v7 in UTC and your local zone. ULIDs are split into time and randomness with a colour-coded layout.

Format and export in bulk

Toggle upper/lower case, hyphens, {braces} or urn:uuid:. Save up to 10,000 IDs as .txt (one per line), .csv (with timestamps) or .json (array).

Use cases

  • Use time-ordered UUID v7 or ULID as database primary keys
  • Create thousands of IDs as CSV for test data
  • Pick a short URL ID length while watching the collision odds
  • Create API keys or webhook signing secrets from a secure random source
  • Find out when — and how — a UUID in your logs was created

Supported formats

Generate

UUID v4UUID v7 (RFC 9562)ULIDNanoID (custom alphabet & length)Tokens: hex, Base64URL, Base64, alphanumeric, custom

Export

.txt (one per line).csv (index, id, timestamp).json (array)

Inspect

UUID v1–v8, nil & max UUIDNo-hyphen, {braced}, urn:uuid: formsULID (Crockford Base32)

Capability matrix

FeatureSupportNotes
Generate UUID v4 / v7Supportedv7 stays ordered within a millisecond
Generate ULID, NanoID and random tokensSupportedUp to 10,000 at once
Decode UUID / ULID time and versionSupportedShows time for v1, v6, v7 and ULID
Generate UUID v1 / v6Not supportedThey can leak MAC address and time; use v7 instead
Generate UUID v3 / v5 (name-based)Not supportedThe inspector only identifies them
Check IDs against an existing datasetPartialCollision probability only; no comparison with your data
Offline useSupportedWorks without a connection once loaded

Limits & notes

  • 1–10,000 IDs per batch.
  • NanoID length 2–256 characters; tokens 1–1,024 bytes (or 1–1,024 characters for character-based formats).
  • UUID v7 and ULID timestamps come from your device clock; a wrong clock means a wrong embedded time.
  • Collision figures are birthday-bound approximations. Randomness quality depends on the browser’s implementation.

Privacy & safety

Generation and inspection happen entirely in your browser. Generated or pasted values are never uploaded or stored, and analytics never include them — safe for creating API keys and other secrets.

FAQ

Should I use UUID v4 or v7?
Use v7 when order matters, such as database primary keys: the time prefix appends new rows at the end of the index and limits fragmentation. Use v4 when you do not want to reveal creation time or need no ordering.
Can UUIDs collide?
In theory, yes — but for UUID v4 you would need about 3.3 × 10^17 IDs to reach a 1% chance. The tool shows the collision odds for whichever type and length you choose.
What is the difference between ULID and UUID v7?
Both start with a 48-bit millisecond timestamp and sort by time. ULID is 26 Crockford Base32 characters that avoid I, L, O and U; UUID v7 uses the standard 36-character form and fits UUID columns and libraries directly.
How long should a NanoID be?
The default 21 characters from a 64-symbol alphabet give about 126 bits — comparable to UUID v4. If you shorten it, make sure the “IDs until a 1% collision chance” figure is far above the total number of IDs you expect.
Can I use it to generate passwords?
Tokens come from a secure RNG, but passwords that people type need thought about symbols and look-alike characters. For passwords, use our Password Studio, which includes a strength checker.

Related tools

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Paste or drop two versions and see added and removed lines, plus the exact words that changed inside each line. Copy or save the result as a unified patch. Nothing leaves your browser.

Regex Tester

Type a pattern and matches light up in the test string instantly. Capture groups, replacement output and what each part of the pattern means are all on one screen — and patterns that would freeze your browser are stopped after one second.

Code Formatter — Format & Minify

Paste code to format it with the language auto-detected. Choose indent, line width, semicolons, quotes and trailing commas; JavaScript, CSS and HTML can also be minified with before/after size and reduction. Your code never leaves the browser.

JSON Studio — Formatter & Validator

Paste JSON to format, minify or validate it instantly. Errors are shown with the exact line, column and cause, and comments or trailing commas can be auto-repaired. Your data never leaves your device.

XML Studio — Formatter & Validator

Paste XML to format, minify or validate it. Errors show the exact line, column and cause, and whitespace that carries meaning (mixed content, xml:space) is never touched. XPath search and JSON conversion are on the same screen. Your data never leaves your device.

YAML / TOML Studio — Validate, Format & Convert

Paste YAML, TOML or JSON to validate, format or convert it. Errors show the exact line and column, and type traps such as “no becomes false” and anything lost in conversion are flagged up front. Your data never leaves your device.

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