💻 Free Online Developer Tools
Free online developer tools — JSON formatter, Base64 encoder, regex tester, JWT decoder, code minifier, and more.
34 tools available · 100% free · No signup required
JSON Formatter
JSON Formatter formats, validates and beautifies JSON online for free. Pretty-print JSON with syntax highlighting, error detection, and minification instantly.
Base64 Encoder / Decoder
Base64 Encoder / Decoder encodes and decodes Base64 strings online for free. Supports text, files, and images with instant conversion and UTF-8 support.
Regex Tester
Regex Tester lets you test and debug regular expressions online for free. Live match highlighting with flags support.
HTML to JSX Converter
Convert HTML to JSX syntax online for free. Automatically converts attributes and class names for React.
Minify CSS / JS / HTML
Minify CSS, JavaScript, and HTML online for free. Reduce file size and improve page load speed.
Beautify CSS / JS / HTML
Beautify and format CSS, JavaScript, and HTML code online for free. Pretty-print with proper indentation.
JSON to CSV Converter
Convert JSON data to CSV format online for free. Export JSON arrays to spreadsheet-ready CSV files.
JWT Decoder
JWT Decoder decodes and inspects JWT tokens online for free. View header, payload, and signature without a server.
UUID Generator
UUID Generator creates random UUIDs (v4) and GUIDs online for free. Generate unique identifiers instantly for databases, APIs, and development. No signup needed.
Timestamp Converter
Convert timestamps to human-readable dates and vice versa. Unix timestamp converter online for free.
SQL Formatter
SQL Formatter formats and beautifies SQL queries online for free. Pretty-print SQL with proper indentation.
XML Formatter
XML Formatter formats and beautifies XML documents online for free. Pretty-print XML with proper indentation.
YAML Formatter
YAML Formatter formats and validates YAML files online for free. Pretty-print YAML with proper indentation.
Markdown Previewer
Markdown Previewer renders Markdown in real-time online for free. Write and preview Markdown with live output.
CSS Gradient Generator
Generate CSS gradients online for free. Create linear, radial, and conic gradients visually.
Box Shadow Generator
Generate CSS box shadows online for free. Create and preview box shadows visually.
Color Palette Generator
Generate color palettes online for free. Create harmonious color schemes for your designs.
CSS Button Generator
Generate CSS buttons online for free. Create beautiful styled buttons with live preview.
HTML Encoder / Decoder
HTML Encoder encodes and decodes HTML entities online for free. Convert special characters to HTML entities.
Diff Checker
Diff Checker compares two texts and finds differences online for free. Highlight additions and deletions.
Code Screenshot Generator
Code Screenshot Generator creates beautiful code screenshots online for free. Make shareable code images for social media.
Unix Timestamp Converter
Get current Unix timestamp and convert between Unix time and dates online for free.
Image to Base64 Converter
Image to Base64 Converter encodes any image into a Base64 data URI online for free. Get ready-to-use CSS and HTML code in your browser.
JSON to YAML Converter
JSON to YAML Converter changes JSON into clean YAML instantly online for free. Validate and convert config data in your browser with no upload.
YAML to JSON Converter
YAML to JSON Converter changes YAML into clean JSON instantly online for free. Validate and convert config data in your browser with no upload.
CSV to JSON Converter
CSV to JSON Converter changes CSV data into a JSON array instantly online for free. Parse headers and rows in your browser with no upload.
JSON to XML Converter
JSON to XML Converter changes JSON into formatted XML instantly online for free. Validate and convert structured data in your browser with no upload.
Base64 to Image Converter
Base64 to Image Converter decodes a Base64 string back into a viewable image online for free. Preview and download the image in your browser with no upload.
URL Parser
URL Parser breaks any URL into its protocol, host, path, query parameters, and more online for free. Inspect and decode URLs in your browser.
Cron Expression Generator
Cron Expression Generator builds and explains cron schedules online for free. Create cron expressions with a plain-English description in your browser.
CSS Flexbox Generator
CSS Flexbox Generator builds flexbox layouts visually and copies the CSS online for free. Adjust alignment and direction with a live preview in your browser.
CSS Grid Generator
CSS Grid Generator builds CSS grid layouts visually and copies the code online for free. Set columns, rows, and gaps with a live preview in your browser.
Markdown to HTML Converter
Markdown to HTML Converter turns Markdown into clean HTML with a live preview online for free. Convert and copy HTML in your browser with no upload.
Hash Generator
Hash Generator creates MD5, SHA-1, SHA-256, and SHA-512 hashes from text online for free. Generate checksums in your browser with no upload.
Developers lose surprising amounts of time to small formatting and encoding chores: pretty-printing a minified JSON blob, decoding a JWT to check its claims, testing a regex against sample input, or Base64-encoding a string for a header. These developer tools put those jobs one tab away, and because they run client-side, you can safely paste tokens and payloads without sending them to an external API.
Built for quick, everyday tasks
Paste an unreadable single-line JSON response and get a properly indented, validated tree you can actually scan. Drop in a JWT and read its header and payload without trusting a third-party decoder with your token. Write a regex and see exactly which parts of your test string match before you commit it to code. Each tool is intentionally focused so it loads fast and does one thing predictably.
Privacy matters for developers too
Tokens, API responses, and config snippets often contain secrets. Every tool here processes input locally in your browser, so nothing you paste is logged or sent over the network. That makes it safe to inspect a production JWT or format a config file that contains internal URLs.