Free Online Developer Tools
36+ tools built for developers. Format and validate JSON. Encode and decode Base64, URLs, and JWT tokens. Generate UUIDs and hashes. Test regex patterns. Minify HTML, CSS, and JavaScript. All in your browser with no server round-trips.
Every tool here uses browser-native APIs. JSON formatting uses JavaScript's built-in parser. Cryptographic hashing uses the Web Crypto API. Base64 encoding uses btoa()/atob(). Your code, tokens, and data never leave your browser tab.
Free Online Developer Tools
36+ browser-based dev tools — format JSON, encode Base64, decode JWT, test regex, generate UUIDs and hashes. Uses native browser APIs. No data sent to servers.
Browse Developer Tools
All Developer Tools (40)
Code Tools(24)
Color Palette Generator
Generate color palettes from any base color using harmony rules: complementary, analogous, triadic.
Color Picker
Pick colors, generate palettes and CSS gradients. HEX, RGB, HSL output.
Cron Expression Generator
Build cron expressions visually. Human-readable output with next 5 scheduled run times.
Cron Expression Parser
Decode any cron expression into plain English. Field breakdown and next 8 scheduled runs.
CSS Gradient Generator
Create linear, radial, and conic CSS gradients visually. Multiple color stops, live preview, copy CSS.
CSS Minifier
Minify CSS and remove unnecessary spaces to optimize stylesheet size.
HTML Minifier
Minify HTML code by removing extra spaces and comments to reduce size.
HTTP Status Codes
Complete reference for all HTTP status codes: 1xx, 2xx, 3xx, 4xx, 5xx with descriptions.
JS Minifier
Compress JavaScript code quickly to reduce file size for faster delivery.
JSON Formatter
Format, validate, and minify JSON. Syntax highlighting and error detection.
JWT Decoder
Decode and inspect JWT tokens. View header, payload, and signature.
JWT Generator
Generate signed JWT tokens with custom header and payload. HMAC-SHA256 signing in your browser.
Markdown Table Generator
Build GitHub Flavored Markdown tables visually. Set alignment, add rows/columns, copy instantly.
Markdown to HTML
Convert Markdown to HTML instantly. Preview rendered output side by side.
Open Graph Extractor
Extract all OG tags, Twitter Card data, and social preview from any URL instantly.
Open Graph Image Generator
Create 1200×630 Open Graph images for social sharing. 4 templates, custom colors, live preview.
Password Generator
Generate strong, secure passwords. Customize length, symbols, and character sets.
Px to Rem Converter
Convert pixels to rem and rem to pixels. Set custom base font size.
Regex Tester
Test and debug regular expressions with live match highlighting and group capture.
Social Media Card Generator
Design social sharing cards for Twitter, Facebook, LinkedIn and Instagram. Download PNG.
SQL Formatter
Format SQL queries with readable indentation and standardized keywords.
Webhook Tester
Create a temporary webhook URL and inspect all incoming HTTP requests in real time.
XML Formatter
Format and beautify XML with proper indentation for readability.
YAML Formatter
Format and beautify YAML online. Normalize indentation and convert YAML to JSON.
Data Tools(16)
Barcode Generator
Generate barcode images locally from text for product codes, IDs, and labels.
Barcode Scanner
Scan barcodes and QR codes with your camera or from uploaded images.
Base64 Encoder/Decoder
Encode text or files to Base64 and decode Base64 strings instantly.
Binary Converter
Convert between Binary, Decimal, Hexadecimal and Octal instantly.
Color Converter
Convert colors between HEX, RGB, and HSL formats instantly.
CSV to JSON
Convert CSV files or text to JSON. Supports headers, custom delimiters.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from text or files.
Hex to Decimal
Convert between hexadecimal, decimal, binary, and octal instantly. Color preview for hex values.
JSON to CSV
Convert JSON arrays to CSV format. Supports nested objects, custom delimiters, and direct download.
Password Strength Checker
Check password strength based on length, complexity, and entropy estimate.
QR Code Generator
Generate QR codes for URLs, text, email, phone and more. Download as PNG or SVG.
QR Code Scanner
Scan QR codes with your camera or from uploaded images. Instant browser-based decoding.
Screen Resolution Checker
Check your current screen, viewport, DPR, and available display resolution.
Timestamp Converter
Convert Unix timestamps to human-readable dates and dates to Unix time. Live current timestamp.
URL Encoder/Decoder
Encode and decode URLs safely for query strings and web requests.
UUID Generator
Generate random UUIDs (v4). Bulk generate and copy with one click.
Most Used Developer Tools
Frequently Asked Questions
Is my code or data sent to a server when I use these tools?
No. All developer tools use browser-native APIs and JavaScript. JSON formatting uses JSON.parse() and JSON.stringify(). Base64 encoding uses btoa() and atob(). JWT decoding uses string splitting and base64 decoding. UUID generation uses crypto.getRandomValues(). Hashing uses the Web Crypto API. None of these make network requests with your data.
Can the JWT decoder verify signatures?
No — signature verification requires the secret key or public certificate used to sign the token. This tool decodes the header and payload (which are base64-encoded, not encrypted) but cannot validate the signature without the key. For production use, always validate JWTs server-side.
Are the generated passwords and UUIDs cryptographically secure?
Yes. Both the Password Generator and UUID Generator use the browser's Web Crypto API (crypto.getRandomValues()), which provides cryptographically secure random values — the same randomness source used by operating systems for security-critical operations.
What does the regex tester support?
The Regex Tester supports JavaScript's native RegExp syntax including flags (g, i, m, s, u). It highlights all matches in real time and shows capture groups. It does not support PCRE or Python regex syntax.
Can I minify large JavaScript files?
The JS Minifier handles typical JavaScript files efficiently. Very large files (500KB+) may take a moment depending on your device. The tool removes whitespace and comments but does not perform deep code transformations like tree shaking or bundling.