API Schema Extractor

What is API Schema Extractor?

API Schema Extractor is a free, browser-based tool that helps you produce ready-to-use output in seconds. Infer a schema from sample responses. It's built for speed and privacy: Everything runs locally in your browser — your data is never uploaded to a server. No sign-up, no installs, and no daily limits.

Used by

• Backend developers
• API testers
• QA engineers
• Integration teams
• Developers
• Test-data teams

Recommended workflow

1. 1

   Prepare the input

   Generate a sample or helper artifact, then copy it into the workflow that needs it.

2. 2

   Run API Schema Extractor

   Review the preview, copy or download the result, and keep everything local in your browser.

3. 3

   Next recommended tool

   API Field Mapper: Map fields between two API shapes.

   Open tool
4. 4

   Then continue with

   API Request Builder: Build an HTTP request visually, then export it as curl, fetch, axios, Python or Go.

   Open tool
5. 5

   Then continue with

   API Response Formatter: Pretty-print and inspect API JSON.

   Open tool

Frequently asked questions

How do I use API Schema Extractor?

Paste or drop your data into the workspace, adjust the options to fit your data, then copy or download the result. Infer a schema from sample responses.

Is my data uploaded or stored anywhere?

No. Everything runs locally in your browser — your data is never uploaded to a server. Nothing is sent to a server, so it's safe to use with private or sensitive data.

Is API Schema Extractor free?

Yes — it's completely free with no account, no sign-up, no watermark, and no daily usage limits.

What's the maximum file size?

There's no hard limit imposed by the tool. Because processing happens in your browser, the practical ceiling is your device's available memory — most everyday files work instantly.

Do I need to install anything?

No installs and no extensions — it runs entirely in your web browser and even works offline once the page has loaded.