# FreeTools.one > Free online developer tools — 203+ utilities for text, code, images, networking, and more. All tools run client-side in the browser, no signup required, no data sent to servers. ## Popular Tools - [JSON Formatter](https://freetools.one/tools/json-formatter): Format, validate & minify JSON data - [Base64](https://freetools.one/tools/base64): Encode and decode Base64 strings - [Color Converter](https://freetools.one/tools/color-converter): Convert between HEX, RGB, and HSL - [Hash Generator](https://freetools.one/tools/hash-generator): Generate SHA-1, SHA-256, SHA-512 hashes - [Word Counter](https://freetools.one/tools/word-counter): Count words, characters & sentences - [Password Generator](https://freetools.one/tools/password-generator): Generate secure random passwords - [QR Code](https://freetools.one/tools/qr-code): Generate QR codes from text or URLs - [Markdown Preview](https://freetools.one/tools/markdown-preview): Preview Markdown in real-time - [Regex Tester](https://freetools.one/tools/regex-tester): Test regular expressions - [SQL Formatter](https://freetools.one/tools/sql-formatter): Format and beautify SQL queries - [HTML to JSX](https://freetools.one/tools/html-to-jsx): Convert HTML to React JSX syntax - [Color Palette](https://freetools.one/tools/color-palette): Generate beautiful color palettes - [IP Address Info](https://freetools.one/tools/ip-info): Look up your IP address details - [HTML Preview](https://freetools.one/tools/html-preview): Live HTML preview in iframe - [JavaScript Runner](https://freetools.one/tools/javascript-runner): Run JavaScript code in browser - [Image Compressor](https://freetools.one/tools/image-compressor): Compress images in browser, no upload - [Fake Data Generator](https://freetools.one/tools/fake-data-generator): Generate fake names, emails, addresses, phones - [Color Contrast Checker](https://freetools.one/tools/color-contrast-checker): Check WCAG color contrast accessibility - [Git Cheatsheet](https://freetools.one/tools/git-cheatsheet): Common Git commands reference - [Regex Cheatsheet](https://freetools.one/tools/regex-cheatsheet): Regular expression syntax reference - [Markdown Live](https://freetools.one/tools/markdown-live): Live markdown editor with real-time preview - [Calculator](https://freetools.one/tools/calculator): Scientific calculator with math functions - [Percentage Calculator](https://freetools.one/tools/percentage-calculator): Calculate percentages, tips, discounts - [Tip Calculator](https://freetools.one/tools/tip-calculator): Calculate tip amount and split bill - [Color Palette](https://freetools.one/tools/color-palette-gen): Generate beautiful color palettes - [Unit Converter](https://freetools.one/tools/unit-converter-ext): Convert between various units of measurement - [Image Resizer](https://freetools.one/tools/image-resizer): Resize images client-side with width/height controls - [JavaScript Formatter](https://freetools.one/tools/js-formatter): Format and beautify JavaScript/TypeScript code - [API Tester](https://freetools.one/tools/api-tester): Make HTTP requests and inspect responses - [Notepad](https://freetools.one/tools/notepad): Quick notepad with auto-save to localStorage - [Markdown Editor](https://freetools.one/tools/markdown-editor): Write markdown with live preview side-by-side - [Meta Tag Generator](https://freetools.one/tools/meta-tag-generator): Generate HTML meta tags for SEO - [YouTube Embed Generator](https://freetools.one/tools/youtube-embed-generator): Generate responsive YouTube embed code with custom options - [Favicon Generator](https://freetools.one/tools/favicon-generator): Create favicons from images or text for your website - [Sitemap Generator](https://freetools.one/tools/sitemap-xml-generator): Generate XML sitemaps for search engines - [GitHub README Generator](https://freetools.one/tools/github-readme-generator): Create beautiful GitHub profile READMEs with badges - [Regex to English](https://freetools.one/tools/regex-to-english): Translate regex patterns into plain English explanations - [Crontab Generator](https://freetools.one/tools/crontab-generator): Build cron expressions visually with human-readable output ## Developer Tools - [JSON Formatter](https://freetools.one/tools/json-formatter): Format, validate & minify JSON data - [Hash Generator](https://freetools.one/tools/hash-generator): Generate SHA-1, SHA-256, SHA-512 hashes - [Markdown Preview](https://freetools.one/tools/markdown-preview): Preview Markdown in real-time - [Live Markdown Preview](https://freetools.one/tools/markdown-preview-live): Write Markdown with live side-by-side preview - [Regex Tester](https://freetools.one/tools/regex-tester): Test regular expressions - [JWT Decoder](https://freetools.one/tools/jwt-decoder): Decode JSON Web Tokens - [CSS Minifier](https://freetools.one/tools/css-minifier): Minify CSS code - [JS Minifier](https://freetools.one/tools/js-minifier): Minify JavaScript code - [HTML Minifier](https://freetools.one/tools/html-minifier): Minify HTML code - [Cron Parser](https://freetools.one/tools/cron-parser): Parse cron expressions - [JSON to TS](https://freetools.one/tools/json-to-typescript): Convert JSON to TypeScript interfaces - [SQL Formatter](https://freetools.one/tools/sql-formatter): Format and beautify SQL queries - [XML Formatter](https://freetools.one/tools/xml-formatter): Format, validate and minify XML - [JSON to CSV](https://freetools.one/tools/json-to-csv): Convert JSON arrays to CSV format - [CSV to JSON](https://freetools.one/tools/csv-to-json): Convert CSV data to JSON format - [YAML to JSON](https://freetools.one/tools/yaml-to-json): Convert YAML to JSON format - [HTML to JSX](https://freetools.one/tools/html-to-jsx): Convert HTML to React JSX syntax - [CSS Units Converter](https://freetools.one/tools/css-units): Convert between px, em, rem, vh, vw, % - [HTTP Status Codes](https://freetools.one/tools/http-status): Complete reference of HTTP status codes - [Markdown Table](https://freetools.one/tools/markdown-table): Generate Markdown tables from data - [ASCII Table](https://freetools.one/tools/ascii-table): Complete ASCII character reference - [Unicode Lookup](https://freetools.one/tools/unicode-lookup): Search and explore Unicode characters - [Email Validator](https://freetools.one/tools/email-validator): Validate email address format - [Credit Card Validator](https://freetools.one/tools/credit-card-validator): Validate credit card numbers with Luhn algorithm - [URL Parser](https://freetools.one/tools/url-parser): Parse URL into components - [HTML Preview](https://freetools.one/tools/html-preview): Live HTML preview in iframe - [JavaScript Runner](https://freetools.one/tools/javascript-runner): Run JavaScript code in browser - [CSS Preview](https://freetools.one/tools/css-preview): Live CSS preview with HTML - [JSON Validator](https://freetools.one/tools/json-validator): Validate and analyze JSON structure - [Markdown to HTML](https://freetools.one/tools/markdown-to-html): Convert Markdown to HTML code - [HTML to Markdown](https://freetools.one/tools/html-to-markdown): Convert HTML to Markdown format - [JSONPath Tester](https://freetools.one/tools/json-path-tester): Test JSONPath expressions against JSON - [XPath Tester](https://freetools.one/tools/xpath-tester): Test XPath expressions against HTML - [JWT Generator](https://freetools.one/tools/jwt-generator): Create JWT tokens with custom payload - [Color Contrast Checker](https://freetools.one/tools/color-contrast-checker): Check WCAG color contrast accessibility - [CSS Specificity](https://freetools.one/tools/css-specificity): Calculate CSS selector specificity - [Git Cheatsheet](https://freetools.one/tools/git-cheatsheet): Common Git commands reference - [Regex Cheatsheet](https://freetools.one/tools/regex-cheatsheet): Regular expression syntax reference - [SVG Optimizer](https://freetools.one/tools/svg-optimizer): Optimize and minify SVG code - [HTML Formatter](https://freetools.one/tools/html-formatter): Format and beautify HTML code - [JSON Minifier](https://freetools.one/tools/json-minifier): Minify JSON by removing whitespace - [XML Minifier](https://freetools.one/tools/xml-minifier): Minify XML by removing whitespace - [Markdown Live](https://freetools.one/tools/markdown-live): Live markdown editor with real-time preview - [JSON Tree Viewer](https://freetools.one/tools/json-tree-viewer): View JSON as an expandable tree structure - [YAML Validator](https://freetools.one/tools/yaml-validator): Validate YAML syntax and check for errors - [Markdown Cheatsheet](https://freetools.one/tools/markdown-cheatsheet): Complete Markdown syntax reference - [HTTP Methods](https://freetools.one/tools/http-methods): HTTP methods reference (GET, POST, PUT, etc.) - [MIME Types](https://freetools.one/tools/mime-types): Look up MIME types by file extension - [OG Tag Preview](https://freetools.one/tools/og-tag-preview): Preview Open Graph social media tags - [Flexbox Playground](https://freetools.one/tools/flexbox-playground): Visual CSS flexbox builder with live preview - [.htaccess Generator](https://freetools.one/tools/htaccess-generator): Generate Apache .htaccess rules for redirects and security - [Nginx Config Generator](https://freetools.one/tools/nginx-config-generator): Generate Nginx server configuration files - [Docker Compose Generator](https://freetools.one/tools/docker-compose-generator): Generate docker-compose.yml files visually - [CSS Grid Generator](https://freetools.one/tools/css-grid-generator): Visual CSS Grid layout builder with code output - [JSON Diff](https://freetools.one/tools/json-diff): Compare two JSON objects and find differences - [JSON Schema Validator](https://freetools.one/tools/json-schema-validator): Validate JSON data against a JSON Schema - [HTML Table Generator](https://freetools.one/tools/html-table-generator): Create HTML tables visually with row/column editor - [Regex to English](https://freetools.one/tools/regex-to-english): Translate regex patterns into plain English explanations - [CSS Selector Generator](https://freetools.one/tools/css-selector-generator): Build CSS selectors visually and test them - [Crontab Generator](https://freetools.one/tools/crontab-generator): Build cron expressions visually with human-readable output - [CSS Specificity Calculator](https://freetools.one/tools/css-specificity-calculator): Calculate CSS selector specificity scores - [Open Graph Preview](https://freetools.one/tools/open-graph-preview): Preview how your page looks when shared on social media - [Markdown to HTML Preview](https://freetools.one/tools/markdown-to-html-preview): Convert Markdown to HTML with live preview and copy output - [Markdown Lint](https://freetools.one/tools/markdown-lint): Check Markdown files for common style issues and errors ## Encoding Tools - [Base64](https://freetools.one/tools/base64): Encode and decode Base64 strings - [URL Encoder](https://freetools.one/tools/url-encoder): Encode and decode URLs - [HTML Entities](https://freetools.one/tools/html-entities): Encode and decode HTML entities - [ROT13 Encoder](https://freetools.one/tools/rot13): Encode and decode ROT13 cipher text - [Morse Code](https://freetools.one/tools/morse-code): Convert text to/from Morse code - [Binary Converter](https://freetools.one/tools/binary-converter): Convert text to/from binary - [Hex Encoder](https://freetools.one/tools/hex-encoder): Encode and decode hexadecimal strings - [Punycode Converter](https://freetools.one/tools/punycode): Convert internationalized domain names - [Base32 Encoder](https://freetools.one/tools/base32): Encode and decode Base32 strings - [Base58 Encoder](https://freetools.one/tools/base58-encoder): Encode/decode Base58 (Bitcoin alphabet) - [Base85 Encoder](https://freetools.one/tools/base85-encoder): Encode/decode Base85 (ASCII85) - [Crockford Base32](https://freetools.one/tools/crockford-base32): Crockford's Base32 encode/decode - [Text Encryptor](https://freetools.one/tools/text-encryptor): Encrypt/decrypt text with password - [String Encoder](https://freetools.one/tools/string-encoder): Encode strings in multiple formats ## Converters Tools - [Color Converter](https://freetools.one/tools/color-converter): Convert between HEX, RGB, and HSL - [Timestamp](https://freetools.one/tools/timestamp): Convert Unix timestamps to dates - [Base Converter](https://freetools.one/tools/base-converter): Convert between number bases - [Chmod Calculator](https://freetools.one/tools/chmod-calculator): Calculate Unix file permissions - [Number to Words](https://freetools.one/tools/number-to-words): Convert numbers to words in any language - [Roman Numerals](https://freetools.one/tools/roman-numerals): Convert numbers to/from Roman numerals - [Temperature](https://freetools.one/tools/temperature): Convert between Celsius, Fahrenheit, Kelvin - [Unit Converter](https://freetools.one/tools/unit-converter): Convert between various units - [CSV to Markdown](https://freetools.one/tools/csv-to-markdown): Convert CSV data to Markdown tables - [JSON to TOML](https://freetools.one/tools/json-to-toml): Convert JSON to TOML format - [TOML to JSON](https://freetools.one/tools/toml-to-json): Convert TOML to JSON format - [XML to JSON](https://freetools.one/tools/xml-to-json): Convert XML to JSON format - [INI to JSON](https://freetools.one/tools/ini-to-json): Convert INI config to JSON - [Color Blindness](https://freetools.one/tools/color-blindness-simulator): Simulate color vision deficiencies - [Number Formatter](https://freetools.one/tools/number-formatter): Format numbers in various styles - [Hex to Decimal](https://freetools.one/tools/hex-to-decimal): Convert hexadecimal to decimal numbers - [Binary to Decimal](https://freetools.one/tools/binary-to-decimal): Convert binary numbers to decimal - [Unit Converter](https://freetools.one/tools/unit-converter-ext): Convert between various units of measurement - [Epoch Converter](https://freetools.one/tools/epoch-converter): Convert epoch milliseconds and seconds to dates - [Timezone Converter](https://freetools.one/tools/timezone-converter): Convert time between timezones worldwide - [JSON to YAML](https://freetools.one/tools/json-to-yaml): Convert JSON to YAML format - [Env to YAML Converter](https://freetools.one/tools/env-to-yaml): Convert .env files to YAML configuration - [XML to YAML Converter](https://freetools.one/tools/xml-to-yaml): Convert XML documents to YAML format - [JSON to Go Struct](https://freetools.one/tools/json-to-go-struct): Convert JSON to Go struct type definitions - [JSON to SQL Converter](https://freetools.one/tools/json-to-sql): Convert JSON arrays to SQL INSERT statements - [HTML to Markdown](https://freetools.one/tools/html-to-markdown): Convert HTML content to Markdown format - [JSON to CSV](https://freetools.one/tools/json-to-csv): Convert JSON arrays to CSV spreadsheets - [JSON to YAML](https://freetools.one/tools/json-to-yaml): Convert JSON to YAML and back - [CSV to JSON](https://freetools.one/tools/csv-to-json): Convert CSV data to JSON arrays - [SQL to JSON](https://freetools.one/tools/sql-to-json): Convert SQL CREATE TABLE statements to JSON schema - [JSON to CSV Converter](https://freetools.one/tools/json-to-csv-converter): Convert JSON arrays to CSV with custom delimiters ## Text Tools - [Word Counter](https://freetools.one/tools/word-counter): Count words, characters & sentences - [Text Case](https://freetools.one/tools/text-case): Convert text to any case format - [Diff Checker](https://freetools.one/tools/diff-checker): Compare two texts line by line - [Line Counter](https://freetools.one/tools/line-counter): Count lines, words & bytes - [Text Reverser](https://freetools.one/tools/text-reverser): Reverse any text string instantly - [Slug Generator](https://freetools.one/tools/slug-generator): Convert text to URL-friendly slugs - [Palindrome Checker](https://freetools.one/tools/palindrome-checker): Check if text reads the same forwards and backwards - [Duplicate Remover](https://freetools.one/tools/duplicate-remover): Remove duplicate lines from text - [Whitespace Remover](https://freetools.one/tools/whitespace-remover): Remove extra whitespace and empty lines - [Text Diff](https://freetools.one/tools/text-diff): Compare texts with word-level diff - [Text Statistics](https://freetools.one/tools/text-statistics): Detailed text analysis and statistics - [Readability Score](https://freetools.one/tools/readability-score): Calculate Flesch-Kincaid readability score - [Case Converter](https://freetools.one/tools/case-converter): Convert between camelCase, snake_case, kebab-case - [Text Sorter](https://freetools.one/tools/text-sorter): Sort lines alphabetically or numerically - [Reading Time Calculator](https://freetools.one/tools/reading-time-calculator): Calculate estimated reading and speaking time for text - [Text to Slug](https://freetools.one/tools/text-to-slug): Convert titles and text to URL-friendly slugs - [Sentence Counter](https://freetools.one/tools/sentence-counter): Count sentences, paragraphs and readability metrics ## Generators Tools - [Lorem Ipsum](https://freetools.one/tools/lorem-ipsum): Generate placeholder text - [Password Generator](https://freetools.one/tools/password-generator): Generate secure random passwords - [QR Code](https://freetools.one/tools/qr-code): Generate QR codes from text or URLs - [UUID Generator](https://freetools.one/tools/uuid): Generate random UUIDs (v4) - [htpasswd](https://freetools.one/tools/htpasswd-generator): Generate .htpasswd entries - [Lorem Picsum](https://freetools.one/tools/lorem-picsum): Generate random placeholder images - [Color Palette](https://freetools.one/tools/color-palette): Generate beautiful color palettes - [Gradient Generator](https://freetools.one/tools/gradient-generator): Create CSS gradients visually - [Box Shadow Generator](https://freetools.one/tools/box-shadow): Create CSS box shadows visually - [Password Strength](https://freetools.one/tools/password-strength): Analyze password strength and security - [Fake Data Generator](https://freetools.one/tools/fake-data-generator): Generate fake names, emails, addresses, phones - [Nano ID Generator](https://freetools.one/tools/nano-id-generator): Generate Nano IDs (compact unique IDs) - [ULID Generator](https://freetools.one/tools/ulid-generator): Generate ULIDs (sortable unique IDs) - [CSS Animation](https://freetools.one/tools/css-animation-generator): Create CSS animations visually - [Lorem Color](https://freetools.one/tools/lorem-color): Generate random color palettes - [Random Number](https://freetools.one/tools/random-number): Generate random numbers in a range - [Color Palette](https://freetools.one/tools/color-palette-gen): Generate beautiful color palettes - [Lorem Picsum](https://freetools.one/tools/lorem-picsum-gen): Generate placeholder images from Picsum - [Meta Tag Generator](https://freetools.one/tools/meta-tag-generator): Generate HTML meta tags for SEO - [UUID v7](https://freetools.one/tools/uuid-v7): Generate time-ordered UUID v7 identifiers - [Color Shades](https://freetools.one/tools/color-shades): Generate tints and shades of any color - [YouTube Embed Generator](https://freetools.one/tools/youtube-embed-generator): Generate responsive YouTube embed code with custom options - [Favicon Generator](https://freetools.one/tools/favicon-generator): Create favicons from images or text for your website - [Robots.txt Generator](https://freetools.one/tools/robots-txt-generator): Generate robots.txt files for SEO crawlers - [Sitemap Generator](https://freetools.one/tools/sitemap-xml-generator): Generate XML sitemaps for search engines - [GitHub README Generator](https://freetools.one/tools/github-readme-generator): Create beautiful GitHub profile READMEs with badges - [Placeholder Image Generator](https://freetools.one/tools/placeholder-image-generator): Generate placeholder images with custom text and colors - [Meta Description Generator](https://freetools.one/tools/meta-description-generator): Generate SEO-optimized meta descriptions for web pages - [Changelog Generator](https://freetools.one/tools/changelog-generator): Generate formatted changelogs from version entries - [.gitignore Generator](https://freetools.one/tools/gitignore-generator): Generate .gitignore files by programming language - [CSS Gradient Generator](https://freetools.one/tools/css-gradient-generator): Create CSS linear and radial gradients with live preview - [OpenAPI Generator](https://freetools.one/tools/openapi-generator): Generate basic OpenAPI/Swagger specification files ## Network Tools - [IP Address Info](https://freetools.one/tools/ip-info): Look up your IP address details - [User Agent Parser](https://freetools.one/tools/user-agent): Parse browser user agent strings - [DNS Lookup](https://freetools.one/tools/dns-lookup): Look up DNS records for any domain - [HTTP Headers](https://freetools.one/tools/http-headers): View and analyze HTTP headers - [HTTP Status Codes](https://freetools.one/tools/http-status-codes): Reference guide for all HTTP status codes with explanations - [SSL Certificate Checker](https://freetools.one/tools/ssl-certificate-checker): Check SSL certificate details and expiry for any domain - [WHOIS Lookup](https://freetools.one/tools/whois-lookup): Look up domain registration and WHOIS information - [CIDR Calculator](https://freetools.one/tools/cidr-calculator): Calculate IP ranges, subnets and network details from CIDR notation ## Image Tools - [Image Compressor](https://freetools.one/tools/image-compressor): Compress images in browser, no upload - [Image Resizer](https://freetools.one/tools/image-resizer): Resize images client-side with width/height controls - [Image Cropper](https://freetools.one/tools/image-cropper): Crop images with interactive selection - [Image to Base64](https://freetools.one/tools/image-to-base64): Convert images to base64 data URIs - [Image Format Converter](https://freetools.one/tools/image-format-converter): Convert between PNG, JPG, WebP, and BMP formats - [SVG to PNG Converter](https://freetools.one/tools/svg-to-png): Convert SVG files to PNG images with custom sizes - [WebP to PNG Converter](https://freetools.one/tools/webp-to-png): Convert WebP images to PNG format - [Image Base64 Converter](https://freetools.one/tools/image-base64-converter): Convert images to Base64 strings and back - [EXIF Viewer](https://freetools.one/tools/exif-viewer): View and extract EXIF metadata from images - [QR Code Scanner](https://freetools.one/tools/qr-code-scanner): Scan and decode QR codes from images or webcam ## Math Tools - [Calculator](https://freetools.one/tools/calculator): Scientific calculator with math functions - [Percentage Calculator](https://freetools.one/tools/percentage-calculator): Calculate percentages, tips, discounts - [BMI Calculator](https://freetools.one/tools/bmi-calculator): Calculate Body Mass Index - [Loan Calculator](https://freetools.one/tools/loan-calculator): Calculate loan payments and interest - [Age Calculator](https://freetools.one/tools/age-calculator): Calculate age from date of birth - [Date Difference](https://freetools.one/tools/date-difference): Calculate difference between two dates - [Tip Calculator](https://freetools.one/tools/tip-calculator): Calculate tip amount and split bill - [Prime Checker](https://freetools.one/tools/prime-checker): Check if a number is prime - [GCD & LCM Calculator](https://freetools.one/tools/gcd-lcm): Calculate Greatest Common Divisor and Least Common Multiple - [Factorial Calculator](https://freetools.one/tools/factorial-calculator): Calculate factorial of a number - [Fibonacci Generator](https://freetools.one/tools/fibonacci-generator): Generate Fibonacci sequence numbers ## Crypto Tools - [AES Encrypt/Decrypt](https://freetools.one/tools/aes-encrypt): Encrypt and decrypt text with AES - [HMAC Generator](https://freetools.one/tools/hmac-generator): Generate HMAC signatures - [Caesar Cipher](https://freetools.one/tools/caesar-cipher): Encode and decode Caesar cipher text - [Vigenere Cipher](https://freetools.one/tools/vigenere-cipher): Encode and decode Vigenere cipher ## Formatters Tools - [JavaScript Formatter](https://freetools.one/tools/js-formatter): Format and beautify JavaScript/TypeScript code - [CSS Formatter](https://freetools.one/tools/css-formatter): Format and minify CSS code - [Python Formatter](https://freetools.one/tools/python-formatter): Format Python code with proper indentation - [Tailwind Class Sorter](https://freetools.one/tools/tailwind-class-sorter): Sort Tailwind CSS classes by recommended order ## API Tools - [API Tester](https://freetools.one/tools/api-tester): Make HTTP requests and inspect responses - [Header Analyzer](https://freetools.one/tools/header-analyzer): Analyze HTTP response headers for security ## Productivity Tools - [Notepad](https://freetools.one/tools/notepad): Quick notepad with auto-save to localStorage - [Color Picker](https://freetools.one/tools/color-picker): Pick colors and get hex, RGB, HSL values - [Markdown Editor](https://freetools.one/tools/markdown-editor): Write markdown with live preview side-by-side - [Pomodoro Timer](https://freetools.one/tools/pomodoro-timer): Focus timer with work/break intervals for productivity - [Countdown Timer](https://freetools.one/tools/countdown-timer): Set a countdown timer with alerts - [Weekly Planner](https://freetools.one/tools/weekly-planner): Simple weekly task planner for organizing your work ## Optional - [Blog](https://freetools.one/blog): Developer tutorials and guides - [About](https://freetools.one/about): About FreeTools.one - [All Tools](https://freetools.one/tools): Browse all tools - [Privacy Policy](https://freetools.one/privacy) - [Terms of Service](https://freetools.one/terms)