UUID Generator
Generate, validate, format, copy, and export UUID v4 identifiers
Use UUID Generator
7f9c2ba4-6d1e-4c08-9a2f-4f8b0d3e1c72Valid random UUID v4. It is suitable for identifiers and correlation IDs, but it does not encode creation time.
Output details
Copy-ready workflow handoff
Generate UUIDs and copy them for fixtures, database seeds, or request IDs.
Confirm whether the destination expects lowercase, uppercase, braces, or JSON array format.
Generated UUIDs are local random identifiers; do not confuse them with secret tokens.
Copy this after replacing the bracketed output with the live result from the tool.
UUID batch handoff: [paste the current tool output here]. Workflow: Generate UUIDs and copy them for fixtures, database seeds, or request IDs. Sample to test: Generate a batch for test fixtures, seed data, mock IDs, or correlation IDs. Output to review: Copy one UUID, all UUIDs, or a JSON array depending on the destination. Invalid/error check: Confirm whether the destination expects lowercase, uppercase, braces, or JSON array format. Privacy note: Generated UUIDs are local random identifiers; do not confuse them with secret tokens. Next check: Use JSON Schema Generator when IDs are part of a sample API payload.
Assumptions
Use UUID Generator for generation workflows work when you need a local browser check and output you can review before using it in the next step.
Worked example
When To Use UUID Generator
- Paste a real example into UUID Generator that includes the edge case you need to check.
- Review whether the output matches produce fresh values or artifacts that match downstream constraints before using it in the next step.
Sample Input And Output Checks
- Start with a sample that includes the failure you are trying to reproduce, not only a clean placeholder.
- Review length, allowed character set, reuse policy, and destination compatibility before trusting the output.
- Validate generated values in the destination environment instead of assuming the first output is production-safe.
About This Tool
Our UUID generator creates RFC 4122 / RFC 9562 compatible version 4 UUIDs using browser-native cryptographic randomness. Generate a single identifier or a batch of up to 100, switch output formats, validate pasted UUIDs, copy JSON arrays, and export a text report for database seeds, API correlation IDs, file names, and distributed system identifiers.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier displayed as 36 characters in the 8-4-4-4-12 hexadecimal format, such as 550e8400-e29b-41d4-a716-446655440000. Version 4 UUIDs use 122 random bits plus fixed version and variant bits, so collision probability is extremely low for normal application workloads without requiring a central ID service.
Key Features
- RFC 4122 Compliance: Generates standard version 4 UUIDs that work across all platforms and programming languages
- Cryptographic Randomness: Uses crypto.randomUUID() for true random generation, not pseudo-random algorithms
- Bulk Generation: Create up to 100 UUIDs at once for batch operations or database seeding
- Format Options: Copy lowercase canonical UUIDs, uppercase UUIDs, compact 32-character values, or URN-prefixed identifiers
- Validation Panel: Check pasted UUIDs for structure, version, variant, and canonical form before using them
- Individual Copy: Copy any single UUID with dedicated copy buttons for quick access
- Copy and Export: Copy all generated UUIDs, copy a JSON array, copy a canonical validation result, or download a text report
- Zero Dependencies: Uses native browser APIs without external libraries for maximum reliability
- Instant Generation: Generate UUIDs in milliseconds with no server round trips
Common Use Cases
UUIDs solve identification challenges across countless software development and system architecture scenarios. For formatting API responses that include UUIDs, use our JSON Formatter tool.
- Database Primary Keys: Use UUIDs as primary keys in distributed databases to avoid ID conflicts during replication or merging
- Session Identifiers: Generate unique session IDs for user authentication and session management in web applications
- File and Resource Naming: Create practically unique filenames for uploads, temporary files, or cloud storage objects
- API Request Tracking: Assign correlation IDs to track requests across microservices and distributed logging systems
- Message Queue IDs: Identify messages uniquely in systems like RabbitMQ, Kafka, or AWS SQS
- Entity Identifiers: Generate IDs for entities in object-oriented systems or document databases like MongoDB
- Distributed Systems: Coordinate between services without requiring centralized ID generation or management
How to Use
Generating UUIDs is quick and straightforward with our simple interface.
- Enter the number of UUIDs you need to generate (1-100) in the count field
- Click "Generate UUIDs" to create your requested number of unique identifiers
- Select canonical lowercase, uppercase, compact, or URN output before copying
- Copy one UUID, copy all generated UUIDs, copy a JSON array, or download a text report
- Paste an existing UUID into the validator to confirm its version, variant, and canonical form
- Use the valid and invalid samples to test the workflow before pasting production identifiers
UUID Versions and Formats
While several UUID versions exist (v1 through v5), version 4 is the most commonly used in modern applications. UUID v1 uses timestamp and MAC address, which can expose information about when and where the UUID was generated. UUID v3 and v5 use namespace-based hashing (MD5 and SHA-1 respectively), suitable when you need deterministic UUIDs from the same input. UUID v4, which this tool generates, uses pure randomness making it ideal for most applications where you simply need a unique identifier without exposing any information. The standard format includes hyphens, but some systems may use a continuous 32-character hex string by removing the hyphens.
UUIDs vs Auto-Increment IDs
Traditional auto-increment integers (1, 2, 3...) have limitations in distributed systems - they require central coordination and create merge conflicts when combining data from multiple sources. UUIDs can be generated independently across different systems with very low collision risk, making them useful for microservices, offline-first applications, and distributed databases. However, UUIDs consume more storage space (128 bits vs 32 or 64 bits) and are not naturally ordered, which can impact database index performance. Choose UUIDs when distribution and practical global uniqueness matter more than storage efficiency and sequential ordering. For time-based unique identifiers, consider using our Timestamp Converter tool.
Technical Implementation
This tool uses the browser's native crypto.randomUUID() method introduced in modern browsers, which generates RFC 4122 version 4 UUIDs using the Web Crypto API's cryptographically strong random number generator. The method automatically formats the UUID with hyphens in the standard 8-4-4-4-12 pattern and sets the appropriate version and variant bits. All generation happens client-side in your browser, ensuring privacy and eliminating network latency.
UUID Generator FAQ
Can I validate a UUID that came from another system?
Yes. Paste a hyphenated UUID, compact 32-character UUID, or urn:uuid value into the validator. The tool reports the canonical form, version digit, and variant bits so you can decide whether it fits a UUID v4 workflow.
Which export format should I use for API payloads?
Use the JSON array copy action when you are preparing fixtures, seed data, or API examples. Use the text report when you need an auditable list that also records the selected output format.
Are UUIDs secret?
No. UUIDs are identifiers, not credentials. For passwords, API secrets, or signing keys, use a dedicated secret generator and store the result in a secure system.