Developer Tools
Over 30 browser-based tools for everyday development tasks: format and validate JSON, minify HTML/CSS/JS, test regex patterns with live matching, generate cron expressions visually, decode JWT tokens, format SQL, and convert between data formats like XML, YAML, and CSV.
From JSON formatters and code minifiers to regex testers and cron generators, these browser-based utilities handle the repetitive tasks that slow down your workflow. Format code, convert between data types, validate configurations, and generate boilerplate — all without leaving your browser. Every tool processes data in your browser with no sign-up or installation required.
Showing 30 developer tools
The fastest way to debug is often a paste-and-read tool, not a full IDE. These utilities cover the five minutes of every developer day that an editor handles badly: malformed JSON, regex you cannot visualize, cron you cannot remember, and tokens you need to inspect right now.
Try JSON Formatter & Validator first
Paste JSON into the formatter first — it is the tool developers reach for more than any other here.
- 1
Paste and format
Drop in any JSON, even minified, and it is beautified with tree-style indentation instantly.
- 2
Read the error line
Invalid input is flagged with the exact line and column instead of a cryptic stack trace.
- 3
Minify for production
Toggle to minified output and copy compact JSON for logs, payloads, or test fixtures.
What Each Tool Does
JSON Formatter & Validator
Paste malformed JSON and get it beautified, minified, or validated with line-numbered error messages. Works with files up to 10MB.
Regex Tester
Type a regex pattern and test string. Matching groups are highlighted in real time. Supports JavaScript regex syntax including lookaheads and named groups.
Cron Expression Generator
Click checkboxes for minutes, hours, days, and months instead of memorizing cron syntax. The tool shows the next 10 execution times so you can verify the schedule.
JWT Decoder
Paste a JWT and see the decoded header, payload, and signature. The tool also shows token expiration time and whether the signature is valid.
Code Minifier
Strip whitespace, comments, and unnecessary characters from HTML, CSS, and JavaScript. Useful for reducing bundle sizes before deployment.
SQL Formatter
Paste a single-line SQL query and get it formatted with proper indentation, line breaks, and keyword highlighting for readability.
Real Ways People Use These
Debugging API Responses
You get a minified JSON blob from an API and can't read it. Paste it into the JSON formatter, get a readable tree view, and find the field you're looking for.
Testing Regex Patterns
You're writing input validation and need to test a phone number regex. The regex tester shows you exactly which parts of the input match and which don't.
Setting Up Scheduled Tasks
You need a cron expression for a daily backup at 3 AM. Instead of looking up the syntax, use the generator to click through the options and copy the result.
Inspecting Auth Tokens
Your API is returning 401 errors. Paste the JWT from the Authorization header into the decoder to check if it's expired or has the wrong claims.
Pick the right tool for the job
Four common scenarios and the tool that handles each one.
| When you need to… | Use | Why |
|---|---|---|
| Validate a minified API response | JSON Formatter | Beautify and validate in one paste, with line-numbered errors. |
| Test a pattern before writing it in code | Regex Tester | Live match highlighting shows exactly what your pattern captures. |
| Set up a scheduled job | Cron Generator | Click the schedule instead of decoding five asterisk fields by hand. |
| Check why an API call returned 401 | JWT Decoder | Decode the header and payload and read the expiry claim instantly. |
Getting the most out of these tools
Keep the regex tester open for validation work
Write the pattern there, copy it into code, and keep the tester open for edge cases like empty strings and Unicode.
Decode JWTs locally, never on random sites
Paste tokens into the decoder rather than third-party sites that may log the contents of your auth tokens.
Minify at build time, not by hand
Use the minifier to check bundle impact, then automate minification in your pipeline so it never drifts.
How it works
All tools process data in the browser using native JavaScript APIs like JSON.parse, DOMParser, and window.crypto. No network requests are made during processing.