How do I format a raw API response?

Copy the JSON response body and paste it into the JSON Formatter. It instantly pretty-prints the data with proper indentation and color-codes nested structures, making deep objects easy to read.

How do I check if an API response is valid JSON?

Use the JSON Validator. It checks that the response is well-formed JSON and reports the exact error location — line and column — so you can pinpoint the syntax problem immediately.

How do I inspect a JWT returned by an API?

Copy the JWT from the Authorization header or response body and paste it into the JWT Decoder. It shows the decoded header, payload claims, and whether the token is currently expired — all without sending the token anywhere.

Debug API Responses Online

Debugging API responses is a routine but time-consuming task for any developer. A raw API response often arrives as a compact, unformatted JSON string that is difficult to read. On top of that, some fields may be Base64-encoded, authentication tokens may be embedded as JWTs, and the structure itself may violate the schema you expect. devtoolkit.sh brings all the tools you need for this workflow into one place. Start by pasting the response body into the JSON Formatter to get readable, indented output. Run it through the JSON Validator to catch structural problems and pinpoint the exact line causing a parse error. If any fields look like Base64 strings, decode them instantly without leaving your browser. And if the response carries a JWT in an Authorization header or response body, the JWT Decoder shows you every claim, the algorithm used, and whether the token has expired. All processing happens client-side — your API responses, tokens, and credentials never leave your device.

{}JSON FormatterHOT

Pretty-print and format JSON with proper indentation.

{}JSON ValidatorHOT

Check if your JSON is valid and find syntax errors.

B64Base64 DecodeHOT

Decode Base64-encoded strings back to readable text.

JWTJWT DecoderHOT

Decode and inspect JSON Web Token header and payload.

FAQ

How do I format a raw API response?: Copy the JSON response body and paste it into the JSON Formatter. It instantly pretty-prints the data with proper indentation and color-codes nested structures, making deep objects easy to read.
How do I check if an API response is valid JSON?: Use the JSON Validator. It checks that the response is well-formed JSON and reports the exact error location — line and column — so you can pinpoint the syntax problem immediately.
How do I inspect a JWT returned by an API?: Copy the JWT from the Authorization header or response body and paste it into the JWT Decoder. It shows the decoded header, payload claims, and whether the token is currently expired — all without sending the token anywhere.