Free Developer Tools
JSON formatters, encoders, converters, generators, validators, and more. Everything runs locally — instant, private, and free.
Popular Tools
10Prettify, minify, and validate JSON with syntax highlighting and instant error detection.
Encode and decode Base64 strings. Supports file-to-Base64 drag-and-drop.
Decode JWT header and payload. Shows expiry time. Never sends your token anywhere.
Convert between YAML and JSON formats instantly, with support for anchors and aliases.
Convert Unix epoch timestamps to and from human-readable dates with timezone support.
Generate bulk UUIDs v4 or v7 with a single click. Copy all at once.
Generate strong passwords with custom length, character sets, and entropy display.
Generate QR codes from any text or URL. Download as SVG or PNG.
Test regular expressions with live match highlighting, group table, and replace mode.
Count characters, words, lines, and sentences. Shows reading time and Flesch readability score.
Formatters
8Prettify, minify, and validate JSON with syntax highlighting and instant error detection.
Format, minify, and validate XML documents with tree view and error highlighting.
Prettify SQL queries with dialect support for PostgreSQL, MySQL, and SQLite.
Prettify and minify HTML markup with proper indentation.
Format and minify CSS stylesheets with configurable indentation.
Format and minify JavaScript code using Prettier in the browser.
Format and validate TOML configuration files with error reporting.
Format and prettify GraphQL queries, mutations, and schema definitions.
Encoders & Decoders
9Encode and decode Base64 strings. Supports file-to-Base64 drag-and-drop.
Encode and decode URL components using encodeURIComponent with bulk mode.
Encode and decode HTML entities like &, <, >, and numeric codes.
Decode JWT header and payload. Shows expiry time. Never sends your token anywhere.
Convert any image to a Base64 data URI for embedding in HTML or CSS.
Look up Unicode metadata for any character or code point, including name, block, and category.
Translate text to Morse code and back, with optional audio playback.
Convert plain text to binary (01010101) and back.
Convert text to hexadecimal and back.
Converters
10Convert between YAML and JSON formats instantly, with support for anchors and aliases.
Convert between JSON and YAML formats instantly.
Convert Unix epoch timestamps to and from human-readable dates with timezone support.
Convert numbers between binary, octal, decimal, and hexadecimal.
Convert colors between HEX, RGB, HSL, HSV, and OKLCH with a visual color picker.
Convert between CSV and JSON formats. Upload a file or paste content directly.
Convert Markdown to HTML with a live split preview, supporting GFM tables and task lists.
Convert between TOML and JSON configuration formats.
Convert between comma-separated (CSV) and tab-separated (TSV) formats.
Convert between XML and JSON data formats.
Generators
9Generate bulk UUIDs v4 or v7 with a single click. Copy all at once.
Generate strong passwords with custom length, character sets, and entropy display.
Generate placeholder text by words, sentences, or paragraphs.
Generate QR codes from any text or URL. Download as SVG or PNG.
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any input text.
Generate random integers or floats with custom min, max, and count.
Generate harmonious color palettes from a seed color using color theory.
Generate realistic fake names, emails, addresses, and phone numbers for testing.
Hash and verify strings with bcrypt in the browser. Nothing leaves your device.
Validators
7Test regular expressions with live match highlighting, group table, and replace mode.
Validate email addresses against RFC 5322 with a detailed explanation of any issues.
Parse cron expressions into human-readable English and show the next N run times.
Calculate IP subnet ranges, broadcast addresses, and usable hosts from CIDR notation.
Validate JSON documents against a JSON Schema using Ajv in the browser.
Validate credit card numbers using the Luhn algorithm and detect card type. Nothing leaves your browser.
Validate ISBN-10 and ISBN-13 numbers with check digit explanation.
Text Utilities
8Count characters, words, lines, and sentences. Shows reading time and Flesch readability score.
Convert text between camelCase, PascalCase, snake_case, kebab-case, SCREAMING_SNAKE, and more.
Compare two texts and highlight differences with unified or side-by-side diff view.
Decompose any URL into protocol, host, path, query parameters, and fragment.
Sort lines of text alphabetically, numerically, or by length. Optional deduplication.
Remove duplicate lines from text with case-sensitive or case-insensitive options.
Create Markdown tables visually with a spreadsheet-like editor.
Convert text to the NATO phonetic alphabet (Alpha, Bravo, Charlie...).
Calculators
6Calculate percentages: X% of Y, X is what % of Y, and % change between two values.
Calculate exact age from a birthdate in years, months, and days. Shows days until next birthday.
Calculate the exact difference between two dates in days, weeks, months, and years.
Convert a time across multiple timezones simultaneously for scheduling across regions.
Convert between integers and Roman numerals (I–MMMCMXCIX).
Perform AND, OR, XOR, NOT, and bit-shift operations with binary, decimal, and hex display.
Web & Network
5Searchable reference of all HTTP request and response headers with descriptions and examples.
Look up MIME types by file extension or search by type string.
Parse any User-Agent string into browser name, version, OS, and device type.
Convert any text to a URL-safe slug with a custom separator.
Build Apache .htaccess redirect rules visually — 301, 302, and rewrite rules.