Free Online Developer Tools
15+ browser-based tools built for web developers, backend engineers, and DevOps. Format JSON, test regex, decode JWTs, encode URLs, convert timestamps, and more — all running locally in your browser with zero uploads.
JSON Formatter & Validator
Format, validate, and minify JSON instantly. Detects syntax errors with line-level feedback.
Regex Tester
Test regular expressions with live match highlighting, group capture, and flag support.
JWT Decoder
Decode and inspect JWT headers, payloads, and expiry claims. Verify token structure.
Base64 Encoder / Decoder
Encode text or binary data to Base64 and decode back. Supports Base64url.
URL Encoder / Decoder
Percent-encode URL components or decode encoded strings. Handles all RFC 3986 reserved characters.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and back. Shows UTC and local time.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or files — client-side only.
UUID Generator
Generate cryptographically random UUID v4 values. Bulk generation supported.
HTML Formatter
Prettify and indent HTML markup for readability.
CSS Formatter
Format and beautify CSS stylesheets with configurable indentation.
SQL Formatter
Beautify SQL queries with consistent indentation and keyword casing.
CSS Unit Converter
Convert between px, rem, em, vw, vh, pt, and % with configurable base sizes.
Screen Resolution Checker
See your screen resolution, viewport, DPR, and which CSS breakpoints match.
Cron Expression Generator
Build cron schedule expressions with a visual editor and plain-English preview.
JSON Diff
Compare two JSON objects side by side and highlight differences.
Why developers use EverydayTools.pro
- ✓No context switching — open a tool, get your answer, close it. No account wall, no onboarding flow, no upsell modal.
- ✓Privacy by design — JWTs, API keys, environment variables, and sensitive payloads never leave your machine. All processing uses browser-native APIs.
- ✓Fast iteration — real-time output as you type, keyboard shortcuts, and copy-to-clipboard on every result means zero friction in your workflow.
- ✓Correct by default — JSON validation follows RFC 8259; timestamp conversion handles UTC and DST; JWT decoding is spec-compliant with RFC 7519.
Frequently Asked Questions
Are these developer tools free?
Yes — all developer tools on EverydayTools.pro are completely free. No signup, no account, no premium tier.
Do these tools send my data to a server?
No. All processing happens in your browser using JavaScript. Your code, tokens, and files never leave your device.
Can I use these tools offline?
Most tools work once the page has loaded — you can disconnect from the internet and they will continue to function for the current session.
Which tool should I use to debug a JWT?
Use the JWT Decoder at /jwt-decoder. It shows the header (algorithm, token type), payload (all claims including exp, iat, sub, iss), and flags expired tokens.
How do I validate JSON from an API response?
Paste the response body into the JSON Formatter at /json-formatter. It validates syntax, reports errors with line numbers, and formats the output with configurable indentation.