Common use cases
- API clients
- Create interfaces from sample responses.
- Frontend typing
- Improve autocomplete and type safety.
- Documentation
- Show expected object shapes in technical docs.
Development · free tool
JSON to TypeScript interface generator
Generate TypeScript interfaces from a representative JSON example.
Your tool
JSON to TypeScript
Use it well
How to use JSON to TypeScript
Steps
- Paste a representative JSON example.
- Set the root interface name.
- Choose readonly if needed.
- Copy the generated TypeScript.
Limits and good practices
Good practices
- Use realistic test values when validating forms, exports or API payloads.
- Keep real customer, banking and production secrets out of public tools.
- Check the output format before copying it into a production workflow.
- Document whether a value is generated, validated, converted or only estimated.
Common mistakes
- Confusing valid format with real-world validity
- A generated or locally validated value can match a format without proving that it exists in an official system.
- Using real production data
- Public utilities are best for test data, demos, fixtures, QA and quick checks, not for confidential values.
FAQ
Frequently asked questions
Does the tool infer optional fields?
Inference is based on the provided example. Missing variants may need manual adjustment.
Can arrays be typed?
Yes. Arrays are inferred from their items.
Should I validate generated types?
Yes. Review the output before using it in production code.
Are my inputs sent to a server?
OnSubmit tools run in the browser whenever the task can be processed locally. Avoid pasting production secrets, real banking details or personal data into public tools.