How to use the UUID Generator in JSON
Generate JSON with UUIDs:
1
Configure the JSON template
Define a base JSON object structure and write `{{uuid}}` literals where you want the identifiers injected.
2
Format JSON structural rules
Click the Format button to enforce indentation and validate that your template maintains perfect JSON syntax.
3
Select UUID version
Choose your generation algorithm: standard random v4, legacy time-based v1, or chronological time-ordered v7.
4
Generate bulk objects
Set the record limit up to 1000 and click Generate. The tool clones the object and injects unique UUIDs per iteration.
When to use this tool
Use this when you need JSON records with UUID identifiers:
- →Seeding relational PostgreSQL or MySQL databases that rely strictly on UUID primary keys
- →Generating thousands of unique dummy transaction IDs in JSON arrays for load testing an API
- →Building test fixtures for a Spring Boot or NestJS backend requiring UUIDv4 format validation
- →Creating chronological mock test datasets using UUIDv7's natively sortable timestamp specifications
- →Generating bulk mocked session or tracing IDs structured as valid JSON requests for Datadog or Splunk
Frequently asked questions
Q:What UUID specifications are supported for generation?
The tool supports absolute RFC standards: v1 (MAC/timestamp), v4 (cryptographic random), and the modern v7 (time-ordered sequential random).
Q:Can I generate multiple UUIDs inside a single nested object?
Yes. You can insert the {{uuid}} placeholder as many times as you like within the JSON template, including deep arrays. Every placeholder is substituted with a completely unique UUID per record iteration.
Q:How do I export the bulk JSON output?
You can either use the one-click copy to clipboard to paste directly into REST clients, or use the download button to save the bulk objects as a `.json` file for database seeding or test runners.
Q:Does it output a single object or an array?
If you set the record count to exactly 1, it outputs a single JSON object. If you request 2 or more records, it automatically wraps the generated objects into a valid JSON array format.
Q:Are these generated UUIDs safe to use in production?
Yes. The identifiers are generated directly in the browser utilizing the official npm 'uuid' package and secure crypto APIs. No generated identifiers or templates are transmitted to our servers.