UUID generator
Generate unique version 4 UUIDs instantly in your browser. Create multiple UUIDs, copy them to your clipboard, or download them as a text file. No signup or server processing required.
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What Is a UUID?
A UUID, short for Universally Unique Identifier, is a 128-bit value used to identify records, objects, resources, and other information in software systems. It provides a practical way to create identifiers without depending on a central service to assign sequential numbers.
UUIDs are commonly used in databases, APIs, web applications, distributed systems, software testing, and file management. Because independently generated UUIDs have an extremely low probability of colliding when generated correctly, they are useful when different applications or services need to create identifiers separately.
A standard UUID is typically displayed as 32 hexadecimal characters separated into five groups by four hyphens.
The familiar format follows an 8-4-4-4-12 character pattern. The characters represent hexadecimal values, while particular bits identify the UUID version and variant.
UUID vs. GUID: GUID stands for Globally Unique Identifier. The two terms generally refer to the same kind of identifier, although GUID is especially common in Microsoft and .NET environments.
What Is a UUID v4?
UUID version 4 is a randomly generated UUID. It uses random or pseudorandom bits for most of its value, with specific bits reserved to indicate the version and variant. A properly implemented UUID v4 generator uses a suitable random-number source to reduce the possibility of duplicate identifiers.
UUID v4 is a widely used choice for general-purpose identification because it does not require a centralized sequence or expose a creation timestamp as part of its standard format.
Random identifiers
Suitable for application records, API resources, test data, file identifiers, and systems that need independently generated IDs.
36 characters displayed
A UUID v4 contains 32 hexadecimal characters and four hyphens, giving it a displayed length of 36 characters.
This online UUID generator creates UUID v4 identifiers using the browser's cryptographic random-number facilities. The output is ready to copy into development workflows, test fixtures, and applications that accept standard UUID strings.
UUID v4 vs. UUID v7
UUID v4 and UUID v7 are two UUID versions designed for different requirements. UUID v4 is based primarily on random bits, while UUID v7 incorporates a Unix timestamp in milliseconds along with random and other defined bits. This makes UUID v7 values sortable approximately by creation time.
| Feature | UUID v4 | UUID v7 |
|---|---|---|
| Generation method | Uses random or pseudorandom bits, with version and variant bits defined. | Combines a Unix millisecond timestamp with random and other defined bits. |
| Time ordering | Does not provide chronological ordering by generation time. | Generally sorts by creation time when represented in the standard format. |
| Typical applications | General identifiers, APIs, test records, files, and application resources. | Database records, event logs, queues, and time-ordered records. |
| Timestamp exposure | The standard UUID v4 format does not encode a generation timestamp. | The timestamp component reveals approximate generation time. |
| Database considerations | Random ordering may be less favorable for some write-heavy indexes. | Time-oriented ordering may help with index locality in suitable database systems. |
Which version should you choose? Use UUID v4 for general-purpose identifiers when random values suit your requirements. Consider UUID v7 when approximate chronological sorting is useful, particularly for records created frequently. Database performance still depends on the database engine, index design, workload, and implementation.
Important: This tool currently generates UUID v4 values only. UUID v7 generation is not available in the current generator.
How to Use This UUID Generator
Generate one UUID or create a batch of identifiers directly in your browser. You can copy the generated results or save them to a text file for later use.
Enter a whole number between 1 and 100 in the quantity field.
Click the Generate UUID button to create new version 4 identifiers.
Each UUID appears on a separate line, making the output easy to read and reuse.
Use Copy all to copy the complete list, or select Download .txt to save the UUIDs as a text file.
Generate a fresh set by entering another quantity and clicking Generate UUID. Use Clear to remove the existing results.
Common Uses of UUIDs
UUIDs help applications distinguish records and resources without relying on a single, globally coordinated numbering sequence. Their practical uses span development, databases, testing, and distributed services.
Database primary keys
Identify users, products, orders, records, and other database entities. UUIDs can be useful when records are created across multiple services or databases.
API development
Assign identifiers to API resources, requests, orders, and objects so applications can refer to individual items consistently.
Software testing
Create identifiers for mock records, test fixtures, sample datasets, and automated testing environments without repeatedly reusing the same IDs.
Files and uploads
Generate distinctive filenames or upload identifiers to reduce naming conflicts when multiple files are processed.
Event tracking and logs
Associate events, application logs, webhook deliveries, and distributed operations with identifiers that make individual records easier to distinguish.
E-commerce applications
Identify products, carts, order records, and transactions within applications that need consistent identifiers across multiple components.
UUIDs are identifiers, not complete authorization or authentication systems. For password-reset links, access tokens, and other security-sensitive secrets, use a token-generation approach designed specifically for that purpose.
Features of This Online UUID Generator
This free UUID generator provides the core functions needed to create, copy, and save UUID v4 identifiers without installing additional software.
- Free UUID generation: Create UUID v4 identifiers directly in your browser.
- Single or bulk generation: Generate between 1 and 100 UUIDs per batch.
- Cryptographic randomness: Uses browser cryptographic random-number facilities when available.
- Copy all: Copy the complete list of generated identifiers in one action.
- TXT download: Save generated UUIDs as a plain-text file, with one UUID on each line.
- Clear results: Remove the current output and return the quantity field to its default value.
- No installation required: Use the tool in a supported web browser.
- Browser-based processing: UUID generation happens in your browser rather than requiring a generation request to a remote server.
Is This UUID Generator Safe to Use?
The generator uses the browser's cryptographic random-number functionality to create UUID v4 values. It first uses crypto.randomUUID() when available and otherwise attempts to create UUID v4 values with crypto.getRandomValues().
These mechanisms are designed for cryptographically strong random values. If the required browser functionality is unavailable, the tool reports an error instead of deliberately falling back to a basic, predictable random-number generator.
UUID generation is performed locally in the browser. The generated values are not submitted to a UUID-generation server by this tool. You should still avoid sharing identifiers that are associated with private records, and you should not treat a UUID as a substitute for a purpose-built authentication secret or access-control mechanism.
Frequently Asked Questions
What is a UUID generator?
A UUID generator is a tool that creates Universally Unique Identifiers for software, databases, APIs, testing, and other applications that need distinct identifiers.
Is a UUID the same as a GUID?
UUID and GUID generally describe the same type of identifier. GUID is the term commonly used in Microsoft technologies, while UUID is the broader standard term.
What is UUID version 4?
UUID v4 is a UUID version that uses random or pseudorandom bits for most of its value, with specific bits identifying its version and variant. It is widely used for general-purpose identification.
Can I generate multiple UUIDs at once?
Yes. Enter a quantity from 1 to 100 and click Generate UUID. The tool generates the requested number of UUID v4 values and displays each on a separate line.
Can I download my generated UUIDs?
Yes. Click Download .txt to save all the currently generated UUIDs in a plain-text file, with one identifier per line.
Are generated UUIDs guaranteed to be unique?
No random UUID scheme can provide an absolute mathematical guarantee that collisions will never occur. However, correctly generated UUID v4 values have an extremely low collision probability for ordinary applications.
Does this generator support UUID v7?
No. The current tool generates UUID v4 values. UUID v7 is a separate version that incorporates a timestamp and supports approximate chronological ordering.
Are my UUIDs uploaded to a server?
The generator creates UUIDs directly in your browser and does not send the generated values to a remote UUID-generation service.
Do I need to install anything?
No. You can use the UUID generator in your web browser without installing a separate application.
Can I use UUIDs as database primary keys?
Yes. UUIDs can be used as database primary keys when the database schema and application support them. Consider storage requirements, indexing, query performance, and your chosen UUID version before making a decision.