JSON API Tester

About JSON API Tester

Test a JSON API online by sending GET, POST, PUT, PATCH, or DELETE from your browser and pretty-printing the JSON response. This free JSON API tester adds Accept and Content-Type headers for you and can attach a Bearer token when the API needs one.

Paste a JSON body to validate it before send. Invalid JSON is rejected so you do not ship a broken payload. The response is formatted when it parses as JSON and left as text when it does not. Status code and elapsed time are shown so slow or failing endpoints are obvious.

Browser security still applies: the API must send CORS headers for the response body to be readable. When it does not, copy the generated cURL command. Pair this tool with the JSON viewer or JSON schema validator after you have a payload.

Calls go from your device to the API; this site does not store the body or token. Use this free JSON REST tester whenever you need a private, quick check of a JSON endpoint.

Features

• Send JSON requests and pretty-print JSON responses
• Parse, look up, convert, or generate API helpers instantly
• Copy results into docs, tickets, or code
• Private debugging without sending payloads to Free Tool Mate
• No signup and no intentional server-side storage of tool input

How to use JSON API Tester

1. Paste a URL, headers, status code, cURL command, or JSON into JSON API Tester.
2. Run the parse, lookup, convert, or generate action.
3. Copy the readable result into your docs, ticket, or code.
4. Processing stays in your browser for private debugging.

Suggested next steps

Continue a common workflow with another Free Tool Mate utility.

1. JSON Beautify — Pretty-print JSON with 2, 3, or 4 space indent
2. cURL Generator — Build a cURL command from URL, token, headers, and body
3. HTTP Headers Viewer — Parse raw HTTP request or response headers

Frequently asked questions