What is the difference between UUID v1 and UUID v4?

UUID v1 is generated from the current timestamp and the machine’s MAC address, which can leak when and where it was created. UUID v4 is fully random, which is why it is the recommended default for most applications.

Are the generated UUIDs stored or sent anywhere?

No. Every UUID is generated locally in your browser using JavaScript. Nothing is transmitted to or stored on any server.

Can I format the UUID without hyphens or in uppercase?

Yes. Use the format options to switch between lowercase/uppercase and with/without hyphens, matching whatever format your database or API expects.

UUID Generator

What it is

The UUID Generator helps you create your UUID password in just a few seconds. A Universally Unique Identifier (UUID) is a 128-bit value used in software systems to identify records and objects uniquely without needing a central coordinator. This free browser-based utility produces secure and unique identifiers whenever you need clean, collision-resistant keys for databases, development workflows, or authentication tokens.

How to use it

Select your UUID version: Choose the specific version you need, such as V4 for random identifiers or V1 for timestamp-based values.
Set the quantity: Specify whether you want a single identifier or need to generate multiple UUIDs at once in a list.
Generate the IDs: Click the generate button to create fresh, unique values instantly right in your browser.
Copy with one click: Use the copy button to send a single identifier or your entire batch directly to your clipboard.

Use cases

Database primary keys: Assign unique identifiers to records across distributed databases without running into conflicting auto-increment IDs.
API request tracing: Attach a distinct UUID header to incoming web requests to track logs and troubleshoot distributed microservices.
Test data generation: Create formatted dummy identifiers when seeding test tables, building staging environments, or mocking API payloads.
Temporary passwords and tokens: Generate high-entropy strings to serve as temporary verification passwords, session IDs, or password reset tokens.
Storage and file naming: Rename uploaded user assets with random UUIDs to avoid filename collisions on storage disks and cloud buckets.

Tips

Keep these practical recommendations in mind when generating and implementing UUIDs in your projects:

Pick the right version for your needs: Version 4 relies purely on cryptographic randomness and is the standard choice for most modern web apps. Version 1 includes timestamp data and a node identifier, which can expose timing details if exposed publicly.
Check system formatting requirements: Standard UUIDs display in lowercase hexadecimal with hyphens. Verify whether your target database expects uppercase characters or requires hyphens removed before saving records.
Transmit sensitive tokens securely: If you use a random UUID as a temporary password, secret key, or session token, always transmit it over encrypted HTTPS connections.

FAQ

Does FlexiToolbox store or log my generated UUIDs?

No, this tool does not store, log, or transmit any of your generated UUIDs. All values are calculated directly inside your web browser using standard client-side cryptographic functions. None of the data leaves your device or touches an external server. Once you close or reload the browser tab, the generated strings disappear from memory unless you explicitly copied them.

What is the difference between UUID Version 1 and Version 4?

Version 4 UUIDs rely entirely on cryptographically secure random numbers, whereas Version 1 UUIDs are generated from the system timestamp and a node identifier. Because Version 4 offers maximum randomness with practically zero risk of collision, it serves as the standard choice for web applications, tokens, and general database IDs. Version 1 is primarily used when records need to be sorted chronologically by creation time.

Can I generate multiple UUIDs at the same time?

Yes, you can generate multiple UUIDs simultaneously. Enter the count you need into the quantity field, and the tool will immediately output a clean, line-separated batch of identifiers. You can then use the one-click copy option to grab the entire list for database seeding, test files, or bulk configuration updates.

Is this UUID generator free to use?

Yes, the UUID Generator on FlexiToolbox is completely free. There are no hidden subscription fees, paywalls, or daily usage caps. You do not need to register an account, log in, or share an email address to generate as many individual or bulk identifiers as your project requires.

Can I use this tool on a mobile device?

Yes, the tool works smoothly on smartphones, tablets, and desktop computers. Because the generation script runs within your web browser, you can open the page on any modern mobile browser, configure your desired version and quantity, and copy your generated identifiers straight to your mobile clipboard.

Are these UUIDs secure enough for temporary passwords or authentication tokens?

Yes, Version 4 UUIDs generated by this tool use your browser's cryptographic random number generator, making them secure and unique. A Version 4 identifier provides 122 bits of raw entropy, making guessing or duplicate collisions practically impossible. When using UUIDs as temporary passwords, remember to hash them securely before saving them to your database.