API Debugging Toolbox
Format, decode, compare, and convert API data.
JSON Formatter
Validate, beautify, minify, and inspect JSON without sending it anywhere.
When to use this JSON formatter
Use it when an API response, webhook payload, config file, or copied log line is too compressed to read. Formatting and validation run in the browser, so pasted data is not uploaded.
Common fixes
- Beautify minified JSON from network logs.
- Validate a payload before sharing it with a teammate.
- Minify a JSON config after editing.
Related tools
JSON Diff
Compare two API responses and see added, removed, and changed fields.
Compare API responses by field
JSON Diff flattens both objects and highlights added, removed, and changed paths. It is useful for checking version changes, test fixtures, and production versus staging responses.
Good inputs
- Two API response examples.
- Old and new configuration objects.
- Webhook payloads from different events.
Related tools
JSON to TypeScript
Infer practical TypeScript interfaces from sample API responses.
Generate TypeScript from API samples
Paste a representative JSON response to create starter interfaces for frontend clients, SDKs, mocks, and integration tests. Review generated types before committing them.
What it infers
- Nested object interfaces.
- Array item types.
- Primitive string, number, boolean, null, and unknown values.
Related tools
JWT Decoder
Decode JWT headers and payloads locally, with readable expiry timestamps.
Decode JWT claims locally
JWT Decoder reads the header and payload so you can inspect auth claims, token expiry, issuer, subject, scopes, and custom fields. It does not verify signatures.
Common checks
- Check whether a token is expired.
- Read user, tenant, role, or scope claims.
- Confirm algorithm and token type from the header.
Related tools
Timestamp Converter
Convert Unix timestamps and ISO dates while debugging logs and tokens.
Convert timestamps while reading logs and tokens
Use the converter for Unix seconds, Unix milliseconds, and ISO date strings. It shows UTC and local time side by side for debugging expiry, retries, and scheduled jobs.
Useful for
- JWT exp and iat claims.
- API log timestamps.
- Retry-after and job schedule debugging.
Related tools
curl Converter
Convert curl commands into fetch and axios snippets for API debugging.
Turn curl into application code
Paste a curl command from docs, DevTools, or a terminal and generate starter JavaScript snippets. The converter handles common method, header, body, and URL arguments locally.
Best fit
- Simple JSON API requests.
- Authorization and content-type headers.
- POST, PUT, PATCH, DELETE, and GET requests.
Related tools
URL Parser
Break URLs into protocol, host, path, hash, and decoded query parameters.
Inspect API URLs and query strings
URL Parser splits a request URL into readable parts and decodes query parameters. It is useful when debugging filters, pagination, redirect URLs, and copied network requests.
What it shows
- Protocol, host, hostname, port, path, and hash.
- Decoded query parameters.
- Repeated query keys as arrays.