Topical hub
Developer debugging tools
Format JSON, decode JWTs, test regex, compare payloads, and build cURL commands—free browser debugging utilities for developers.
Topic guides
Browse focused guides that compare related tools and link to the best starting point for your task.
- JSON toolsFormat, validate, compare, and convert JSON with free developer utilities in your browser.
- JWT toolsDecode, encode, and generate JSON Web Tokens in your browser with Utilnivo JWT tools.
- Encoding toolsBase64, URL, and HTML encoding utilities for developers — free and browser-based.
- FormattersFormat and minify HTML, CSS, JavaScript, SQL, XML, YAML, and Markdown in your browser.
- Network toolsDNS, WHOIS, SSL, HTTP headers, and cURL helpers for quick network debugging in your browser.
- Security toolsHash, checksum, and regex utilities for developers — free browser-based security helpers.
- UUID toolsGenerate and decode UUIDs with free developer tools in your browser.
- Developer debugging toolsFormat JSON, decode JWTs, test regex, compare payloads, and build cURL commands—free browser debugging utilities for developers.
Tools in this guide
Overview
Debugging sessions bounce between formats: pretty-printing API JSON, inspecting JWT claims, testing regex against log lines, and reproducing requests in cURL. This hub groups the utilities developers open first when a integration misbehaves.
JSON Formatter and JSON Validator clean up responses; JSON Compare diffs staging vs production payloads. JWT Decoder exposes header and payload without claiming signature verification. Regex Tester, Base64 Encoder, and Hash Generator handle small encoding puzzles. cURL Builder turns UI actions into reproducible terminal commands.
Use the Debug JWT token workflow when you are tracing OAuth or API gateway tokens step by step. Pair network lookups in the Network tools guide when DNS or TLS is suspect.
How to choose
- Messy API JSON → JSON Formatter.
- Invalid JSON error → JSON Validator.
- Environment diff → JSON Compare.
- Bearer token → JWT Decoder.
- Pattern in logs → Regex Tester.
- Reproduce HTTP call → cURL Builder.
Frequently asked questions
Does JWT Decoder verify signatures?
It shows structure for debugging. Verification belongs in your backend with proper keys.
Is my JSON sent to a server?
These developer tools run locally in your browser unless a page explicitly performs a lookup.
What about HTTP header inspection?
Use HTTP Header Checker in the SEO launch checklist hub when you need live response headers.
Step-by-step workflows (1)
Multi-step guides that chain tools from this topic—follow numbered steps instead of guessing tool order.