UUID Generator – Free UUID v4 & GUID Tool
Generate one UUID v4 or a batch of random IDs in your browser. Choose the format your application expects, then copy or download the results.
UUID v4 · Bulk generation · GUID-style formatting · No sign-up
Ready to generate.
UUID v4 values are generated locally with your browser’s cryptographic random-number source. Each batch is checked for duplicate values within that batch. Uniqueness across every system is not guaranteed, and UUIDs are not passwords or authentication tokens.
Check a UUID v4
Paste an ID to check its UUID v4 version and variant markers. This checks formatting only, not whether an ID has been used before.
Accepts hyphenated, brace-wrapped or 32-character hexadecimal UUIDs.
How to generate UUID v4 values
- Choose a quantity. Generate a single identifier or a batch of up to 500 for test records, files or spreadsheet rows.
- Choose the display format. Keep the standard hyphenated UUID, add braces for a GUID-style field, or remove hyphens if your destination requires it.
- Generate and review. Select Generate UUIDs. Use uppercase if required by the destination system; changing display options does not generate new IDs.
- Copy or download. Copy all lines or download the list as a plain-text file. Keep your output somewhere permanent if you need the same identifiers later.
UUID v4 format: a practical example
A standard UUID has 32 hexadecimal digits displayed in five groups separated by hyphens. In UUID v4, the first character of the third group is 4; the first character of the fourth group is 8, 9, a or b. These mark its version and variant.
Standard UUID
Example: 550e8400-e29b-41d4-a716-446655440000. Use when a system expects the familiar hyphenated format.
GUID-style braces
Example: {550E8400-E29B-41D4-A716-446655440000}. The braces and letter case alter presentation, not the underlying identifier.
UUID v4 uses 122 randomly generated bits and fixed version/variant bits. A collision is unlikely with an appropriate random source, but no UUID system can promise absolute global uniqueness. Read the UUID v4 standard (RFC 9562).
When to use a bulk UUID generator
Database imports
Prepare independent identifiers for rows that will be inserted into a database. Apply the database’s own unique constraints and confirm the destination field accepts the selected format.
API and application testing
Create example object IDs for sample requests, mock responses, logs or test fixtures without manually inventing unique-looking values.
File and job identifiers
Generate filenames or job references with a low risk of accidental collision. Keep appropriate access controls for files and jobs.
GUID-style output
Choose braces or uppercase presentation for an application or document that requests that appearance. Verify its field requirements before importing.
What this generator does not do
It generates random UUID version 4 values, not time-ordered UUID v7 or a UUID based on a name or timestamp. It cannot confirm that an identifier is unused in a remote database. Its checker verifies the UUID v4 pattern only; it does not authenticate a user or inspect a stored record.
Use UUIDs to identify records, not to grant access. A public-facing record should still have authorization checks. For real sessions and secrets, use your application’s purpose-built security mechanisms rather than assuming that an ID alone provides protection.
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Frequently asked questions
What is the difference between a UUID and a GUID?
UUID is a standard identifier term. GUID is commonly used in Microsoft-related tools for the same general style of 128-bit identifier. The braces and uppercase options here are display formats; they do not change the UUID version.
Can I generate multiple UUIDs at once?
Yes. Choose any whole number from 1 to 500, then copy the list or save it as a text file containing one identifier per line.
Are UUID v4 values guaranteed to be unique?
No. They are randomly generated with a very low collision probability when a suitable random source is used. Enforce uniqueness in the database or system where it matters.
Does the tool send generated identifiers to a server?
No server request is needed to generate these values. The generation and formatting logic runs in your browser, although the website itself may load normal site resources and analytics.
Can I use a UUID as a password or access token?
No. This tool creates identifiers, not credentials. Use authentication, authorization, and a proper token-generation workflow for protecting accounts or resources.
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