All Developer Tools
44 free tools that run entirely in your browser — nothing you paste, upload, or generate here is sent to a server. Pick a category below or search the full list.
Text & Data Tools
Base64 Encoder & Decoder
Text & Data ToolsEncode text to Base64 or decode Base64 instantly in your browser. Free UTF-8 Base64 encoder and decoder with no signup required.
Case Converter
Text & Data ToolsConvert text between uppercase, lowercase, Title Case, camelCase, PascalCase, snake_case, kebab-case, and more instantly online.
CSV ⇄ JSON Converter
Text & Data ToolsTransform CSV files into JSON or convert JSON arrays back to CSV with automatic type detection. Fast, browser-based, and privacy-friendly.
Difference Checker
Text & Data ToolsCompare two text files or code snippets with line-by-line and word-by-word highlighting. Quickly identify additions, deletions, and changes.
JSON Difference
Text & Data ToolsCompare two JSON objects and quickly identify added, removed, or modified keys with a clear structural difference viewer.
JSON Formatter
Text & Data ToolsBeautify, validate, and minify JSON with instant syntax error detection and line numbers. Fast, browser-based, and privacy-friendly.
JSON Minifier
Text & Data ToolsReduce JSON file size by removing unnecessary whitespace while preserving valid data. Ideal for APIs, storage, and faster data transfer.
Line Tools
Text & Data ToolsSort text lines alphabetically, remove duplicate entries, and trim whitespace in seconds. Perfect for cleaning lists, logs, and text files.
Lorem Ipsum Generator
Text & Data ToolsGenerate placeholder text by paragraphs, sentences, or words for web design, UI mockups, prototypes, and publishing projects.
Markdown Previewer
Text & Data ToolsWrite and preview Markdown with live HTML rendering in real time. Perfect for README files, documentation, notes, and blog content.
Regex Tester
Text & Data ToolsTest and debug regular expressions with live match highlighting, flag support, and instant results. Ideal for JavaScript, Python, and PCRE patterns.
Slug Generator
Text & Data ToolsCreate clean, SEO-friendly URL slugs from any text with customizable separators, lowercase conversion, and special character removal.
URL Encoder/Decoder
Text & Data ToolsEncode or decode URLs and query strings with instant percent-encoding support. Perfect for web development, APIs, and debugging.
Word Counter
Text & Data ToolsCount words, characters, sentences, paragraphs, reading time, and speaking time instantly. Perfect for writers, students, and content creators.
XML Formatter
Text & Data ToolsBeautify, validate, and indent XML with instant syntax error detection. Ideal for editing, debugging, and improving XML readability.
YAML ⇄ JSON Converter
Text & Data ToolsConvert YAML and JSON instantly while preserving data structure and formatting. Great for configuration files, APIs, and development workflows.
Color Tools
Color Picker
Color ToolsSelect colors visually and convert between HEX, RGB, HSL, and CSS formats instantly. Copy accurate color values for web and graphic design.
Contrast Checker
Color ToolsMeasure color contrast ratios and verify WCAG AA and AAA accessibility compliance for text, backgrounds, and user interface elements.
CSS Border Radius Generator
Color ToolsCreate rounded corners with a visual editor, live preview, per-corner controls, and copy-ready CSS for buttons, cards, and UI elements.
CSS Gradient Generator
Color ToolsDesign linear and radial gradients with multiple color stops, live preview, angle controls, and copy-ready CSS for modern web projects.
CSS Shadow Generator
Color ToolsCreate single or multiple CSS box-shadow effects with a live preview, adjustable blur and spread, and copy-ready CSS for any element.
Date & Time
Cron Builder
Date & TimeCreate, parse, and validate cron expressions with instant plain-English explanations for scheduling jobs and automated tasks.
Date Difference Calculator
Date & TimeFind the exact difference between two dates in years, months, weeks, and days with fast, accurate calculations.
Timestamp Converter
Date & TimeConvert Unix timestamps to readable dates and back with support for seconds, milliseconds, UTC, and local time zones.
CSS Tools
API Tools
cURL Generator
API ToolsGenerate cURL commands with custom methods, URLs, headers, query parameters, and request bodies for API testing.
HTTP Status Lookup
API ToolsSearch HTTP status codes and understand their meanings with clear explanations, categories, and common use cases.
MIME Type Lookup
API ToolsFind MIME types by file extension or look up file extensions for content types used in HTTP and file uploads.
Web Tools
Code Generators
Gitignore Generator
Code GeneratorsGenerate custom .gitignore files by combining templates for programming languages, frameworks, editors, and operating systems.
README Generator
Code GeneratorsCreate professional README.md files with sections for installation, usage, features, badges, and licensing in minutes.
robots.txt Generator
Code GeneratorsGenerate a valid robots.txt file with custom user-agent rules, allow and disallow directives, and sitemap support.
Sitemap Generator
Code GeneratorsGenerate a valid sitemap.xml from your URLs with priority, change frequency, and search engine submission support.
Encoding & Hashing
Hash Generator
Encoding & HashingGenerate SHA-1, SHA-256, SHA-384 and SHA-512 hashes from text instantly, using your browser's built-in Web Crypto API.
Password Generator
Encoding & HashingGenerate strong, secure random passwords with customizable length and character sets using browser-based cryptographic randomness.
Password Strength Checker
Encoding & HashingTest password strength with entropy analysis, crack time estimates, and security tips, all processed locally in your browser.
UUID Generator
Encoding & HashingGenerate RFC 4122 version 4 UUIDs in bulk, free and instantly in your browser. Copy single IDs or export a batch as a list.
HTML Tools
Image Tools
Image Compressor
Image ToolsCompress JPEG and WebP images online with adjustable quality settings and instant file size comparison.
QR Code Generator
Image ToolsCreate downloadable QR codes from text or URLs with custom sizes, colors, and instant browser-based generation.
SVG Optimizer
Image ToolsOptimize SVG files by removing metadata, comments, and unnecessary whitespace to reduce file size and improve performance.