Debug an API response from raw payload to readable data — without leaving the browser.
When you are debugging an API, the raw response is rarely the whole story. You need to pretty-print the JSON, decode the auth token to check its claims, verify a hash, or diff two versions of the same payload to spot what changed. Switching between five different single-purpose sites for that is slow and, worse, means pasting real tokens and data into services you do not control.
This toolkit chains the tools you actually reach for during API debugging into one workflow, in the order you typically need them. Everything runs client-side — nothing you paste here is ever sent to a server, which matters when the payload contains a live session token or production data.
Workflow
JSON Formatter — Format & validate the JSON payload: Paste the raw API response to pretty-print it and catch syntax errors instantly.
JWT Decoder — Decode the JWT: Inspect the header, payload claims and expiry of the auth token used in the request.
Base64 Encoder — Encode or decode Base64: Read Base64-encoded headers, cookies or embedded payloads.
UUID Generator — Generate test UUIDs: Create valid v4 UUIDs for test fixtures or mock records.
Hash Generator — Hash a value: Compute MD5/SHA hashes to verify integrity or match a stored digest.
Regex Tester — Test the regex: Confirm the pattern used to validate an input actually matches (or rejects) it.
Diff Checker — Diff two responses: Compare staging vs. production, or before/after a fix, line by line.
SQL Formatter — Format the SQL query: Clean up a minified or copy-pasted query before reviewing it.
HTTP Status Codes — Look up the HTTP status code: Get the exact meaning of the status code the API returned.
Cron Explainer — Explain the cron expression: Translate a scheduler expression into plain English.
Timestamp Converter — Convert the timestamp: Turn Unix timestamps from logs into a readable date in your timezone.
Checklist
Validate the JSON payload structure
Decode the JWT and check its expiry/claims
Confirm any Base64-encoded values decode correctly
Diff staging vs. production (or before/after) response
Format and review any embedded SQL query
Convert log timestamps to your local timezone
FAQ
Is this developer toolkit free to use?
Yes. Every tool in this toolkit is 100% free, with no usage limits, signup or premium tier.
Is it safe to paste production tokens or data here?
Yes — every tool listed runs entirely in your browser. Nothing you paste is sent to a server, so it is safe to use with real JWTs, session data or production payloads.
Do I have to follow the steps in this exact order?
No, the order simply reflects a typical API-debugging session. Jump to any tool directly — each one works standalone.
Can I use these tools together with Postman or curl?
Absolutely. Paste the response body or headers from Postman, curl or your browser devtools directly into any tool here.