Seed data, correlation identifiers, and idempotency keys all need values that will not collide, and typing them by hand produces suspiciously patterned test data.
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UUID Generator
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Free · API · MCPToolYour platform
Use UUID Generator three ways
The free UUID Generator on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse UUID Generator here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is UUID Generator?
Seed data, correlation identifiers, and idempotency keys all need values that will not collide, and typing them by hand produces suspiciously patterned test data. This UUID generator returns between one and fifty identifiers per call, drawn from the platform's cryptographic random source rather than a seeded pseudo-random generator.
Version 4 is the default and is a standard random UUID. The v7 option is an approximation: it prefixes a millisecond timestamp so identifiers sort roughly in creation order, which is useful for readable fixtures, but it is not a certified RFC 9562 implementation — verify against the specification before you depend on the bit layout in production. This is a generator, not a distributed identifier service, and it does not offer ULIDs, snowflakes, or coordination between callers. For the timestamp side of fixtures, Timestamp Converter is the peer tool.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/uuid-generator and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about UUID Generator?
Should I use v4 or v7?
Use v4 unless you specifically want database keys that sort by creation time. The v7 output here is an approximate time-ordered form, so check it against the spec first.
How many can I generate at once?
Between 1 and 50 per call. Larger batches are better generated in your own runtime than fetched over the network.
Is the randomness suitable for secrets?
It comes from the platform crypto source, but a UUID is an identifier, not a secret. Use a dedicated password or token generator for credentials.
What are the key features of UUID Generator?
Bulk output up to 50
Fill a fixture file or a seed script in one call rather than fifty.
Crypto-backed randomness
Values come from the platform cryptographic source, not a seeded PRNG.
Time-ordered option
The approximate v7 form prefixes a timestamp so generated identifiers read in order.
How do you use UUID Generator?
Pick the version
v4 for plain random identifiers, v7 when creation order matters.
Set the count
Anything from a single identifier to fifty in one response.
Copy into your fixtures
Paste into seed data, test payloads, or correlation headers.
Random versus time-ordered identifiers
The trade-off is about database behaviour. Version 4 is entirely random, which spreads inserts across a B-tree index and can fragment pages on write-heavy tables. Version 7 puts a timestamp in the high bits, so new rows land near each other and index locality improves — the reason it has become popular as a primary key.
The cost of v7 is that the creation time is readable from the identifier. If your identifiers appear in public URLs and the creation time is sensitive, that leaks. For fixtures and correlation identifiers the leak does not matter and the readability is a bonus, which is the case this tool is built for.
Building test fixtures across the cluster
Realistic fixtures usually need identifiers and timestamps together. Generate the identifiers here, then use Timestamp Converter to produce matching ISO and epoch values so a record's created-at field is consistent across systems.
If the fixture is a whole payload, JSON Formatter keeps it readable in the repository, and JSON to TypeScript turns the finished sample into a type your tests can share.
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