Developer Tools — 25 Free Online Tools
All developer tools run 100% in your browser — free, private, no sign-up.
Small tools that save developers big time. Data: JSON formatter, YAML to JSON, CSV to JSON, Base64 encode/decode, URL encoder, hash generator (MD5/SHA), UUID generator, JWT decoder, timestamp converter and a regex tester. Front-end: color picker and converter, CSS gradient, box-shadow, text-shadow, border-radius, flexbox and grid generators. Plus code minifier, SQL formatter, HTML to Markdown, Markdown to HTML, meta tag generator, robots.txt and .htaccess generators.
No accounts, no ads in your way, and nothing you paste ever leaves the browser — safe even for tokens and internal JSON. All tools are keyboard-friendly and mobile-responsive.
JSON Formatter
Format, beautify & validate JSON.
Color Picker
Pick colors, get HEX, RGB & HSL.
Base64 Encode/Decode
Encode or decode Base64 text.
Hash Generator
SHA-256, SHA-1 & SHA-512 hashes.
URL Encode/Decode
Encode or decode URL text.
Timestamp Converter
Convert Unix epoch ↔ date/time.
UUID Generator
Generate random UUID v4 strings.
Markdown to HTML
Live Markdown to HTML preview with raw output.
HTML to Markdown
Convert HTML to clean Markdown using Turndown.
CSV to JSON Converter
Convert CSV to JSON and back with auto-delimiter detection.
YAML to JSON Converter
Convert YAML to JSON and JSON to YAML.
SQL Formatter
Beautify and format SQL queries.
Code Minifier
Minify or beautify HTML/CSS/JS code.
Regex Tester
Test regex patterns with live match highlighting.
JWT Decoder
Decode JWT header and payload, show expiry.
Color Converter
Convert HEX, RGB, HSL, CMYK with live swatch.
Meta Tag Generator
Generate SEO meta, Open Graph, and Twitter Card tags.
Robots.txt Generator
Build robots.txt with disallow rules, sitemap, crawl delay.
.htaccess Generator
Combine common Apache rewrite rules and optimizations.
CSS Gradient Generator
Create linear/radial gradients with live preview.
Box Shadow Generator
Craft box-shadow with sliders and live preview.
Border Radius Generator
Adjust rounded corners individually or linked.
Text Shadow Generator
Add custom text-shadow with live preview.
Flexbox Generator
Visually build flex containers and copy CSS.
CSS Grid Generator
Define grid rows, columns, gaps and get CSS.
Frequently Asked Questions
Is it safe to paste JWTs and API responses here?
Yes. Decoding and formatting happen locally in your browser — no data is transmitted or logged.
Does the regex tester support JavaScript syntax?
Yes, it uses your browser’s native JavaScript regex engine with live match highlighting and flag toggles.
Can I minify CSS and JavaScript here?
Yes, the Code Minifier handles HTML, CSS and JavaScript for quick size savings before deployment.