Free browser-based utilities for developers. Each tool runs entirely in your browser — nothing is uploaded to any server. From JSON formatting and text processing to SEO optimization and security analysis, find every tool you need for your daily development workflow.
The most frequently searched developer tools on the web. These utilities answer the most common questions developers have when working with data, tokens, and patterns.
Common developer tasks that span multiple tools. Use these workflow clusters to move efficiently through your daily debugging, data transformation, and security testing routines.
Inspect and test HTTP endpoints, WebSocket connections, and API responses. Build requests, check status codes, and convert curl commands.
Format, validate, and compare JSON documents. Convert between JSON and YAML, CSV, XML, or TOML. Query data with JSONPath expressions.
Encode and decode data for safe transmission. Convert between Base64, percent-encoded URLs, and HTML entities. Transform text between naming conventions.
Decode, inspect, and generate JWT tokens. Hash passwords with bcrypt, generate HMAC signatures, and create secure random UUIDs.
Transform data between common developer formats. Convert images between JPEG, PNG, WebP, and AVIF. Merge PDFs or convert JPG to PDF.
Quick answers to everyday developer questions. Each link leads to the exact tool you need to solve that specific problem.
How to format JSON online?
→ JSON Formatter & Validator
How to decode a JWT token?
→ JWT Decoder
How to convert CSV to JSON?
→ CSV to JSON Converter
How to encode URL parameters?
→ URL Encode/Decode
How to generate a secure password?
→ Password Generator
How to compare JSON files?
→ JSON Compare
How to test a regex pattern?
→ Regex Tester
How to generate a sitemap?
→ Sitemap Generator
Browse by category to find the right utility for your task. Each category groups tools by their primary function.
AI developer tools for prompt engineering and token management.
Format and structure AI prompts with markdown preview and template variables.
Count tokens for GPT-4, GPT-3.5, Claude, and Llama models.
Compare AI model outputs side by side for quality evaluation.
Convert JSON schemas into structured AI prompts for structured output generation.
Generate regular expressions from natural language descriptions.
Get a plain-English explanation of any JSON structure, including fields, types, and nesting.
Build SQL queries from natural language descriptions using a pattern-based engine.
API testing and HTTP debugging utilities.
Send HTTP requests (GET, POST, PUT, DELETE) and inspect responses from your browser.
Connect to WebSocket endpoints, send messages, and inspect frames.
Searchable reference of all HTTP status codes with descriptions and use cases.
Build HTTP requests interactively and generate code snippets in multiple languages.
Convert curl commands to JavaScript fetch, Python requests, and more.
Validate OpenAPI 3.x and Swagger 2.0 specifications for correctness.
Generate mock API responses from JSON schemas for rapid development.
Convert docker run commands to docker-compose.yml format instantly.
Generate realistic fake data including names, emails, phone numbers, addresses, and more.
Date and time conversion utilities.
Convert between Unix timestamps and human-readable dates instantly.
Calculate exact age from date of birth in years, months, days, hours, and minutes.
Calculate the exact difference between two dates in years, months, days, and more.
Generate and explain cron schedules with a visual builder.
Image processing and QR code tools.
Create custom QR codes with colors, logos, and sizes.
Compress images in your browser reducing file size without losing quality.
Compress images with precise quality control. Reduce file size by adjusting quality, removing metadata, and more.
Convert between image formats including JPEG, PNG, WebP, and AVIF.
Convert HEX, RGB, HSL, and named colors instantly with a color picker.
Convert BMP bitmap images to PNG format with lossless compression. Reduce file size up to 90% while preserving every pixel.
Minify and optimize SVG files by removing unnecessary data.
Encode images to Base64 data URIs for embedding in HTML or CSS.
Remove image backgrounds online for free. Click to select a background color and the tool automatically removes matching pixels with adjustable tolerance.
JSON formatting, validation, and transformation tools.
Format, minify, validate, and explore JSON with tree view, JSONPath queries, and multi-format export — the complete JSON workbench.
Compare two JSON files side by side with real-time diff highlighting.
Convert CSV data to JSON format with support for headers and custom delimiters.
Convert YAML data to JSON format with support for complex nested structures.
Validate JSON data and detect syntax errors with detailed error messages and line numbers.
Convert JSON data to TOML format for configuration files.
Generate JSON Schema (draft-07) from sample JSON data automatically.
Convert HTML markup to structured JSON and back.
Convert JSON arrays to CSV format with customizable delimiter, headers, and nested object flattening.
Extract values from JSON using dot-notation and bracket-notation paths.
Convert JSON to TypeScript interfaces instantly. Generate typed interfaces from JSON samples for type-safe development.
Convert JSON to Python dataclasses instantly. Generate typed Python classes from JSON samples for type-safe data handling.
Convert JSON to Java POJO classes instantly. Generate Java records or classes with getters and fields from JSON samples.
Convert JSON to C# classes instantly. Generate C# POCO classes with properties and attributes from JSON samples.
Convert JSON to Go struct types instantly. Generate Go structs with JSON tags from JSON samples for Go development.
Convert JSON to GraphQL schema types instantly. Generate GraphQL type definitions from JSON samples for your API schema.
Convert JSON to Rust structs instantly. Generate type-safe Rust structs with Serde derive macros from JSON samples.
Convert JSON to Swift Codable structs instantly. Generate type-safe Swift structs with Codable conformance from JSON samples.
Convert between JSON and XML formats bidirectionally.
Test JSONPath expressions against JSON data and see matched results.
Minify JSON by removing all whitespace, indentation, and line breaks to create compact payloads.
Extract all values of a specific key from JSON data. Enter a key name and get all matching values in a clean list for copy or download.
Math calculators and number converters.
Convert length, weight, temperature, area, and volume units.
Convert between binary, octal, decimal, and hexadecimal number systems.
Calculate percentages easily with three common modes.
Convert Unix file permissions between numeric and symbolic formats.
Generate cryptographically secure random numbers with custom ranges and count.
Perform scientific calculations with trigonometric, logarithmic, and exponential functions.
Next.js utility tools for configuration and routing.
Visual builder for Next.js App Router routes including groups and parallel routes.
Build and test Next.js middleware config matcher patterns visually.
Parse and explore next.config.js/ts options with descriptions and defaults.
Calculate optimal image dimensions, sizes, and srcset for Next.js Image.
Generate Next.js App Router API route boilerplate with type safety.
Security and cryptography utilities.
Decode and inspect JWT tokens instantly.
Generate strong, secure random passwords with customizable options.
Generate memorable, secure passphrases from word lists.
Generate UUID v4 identifiers instantly.
Validate UUID strings and identify the version (v1, v2, v3, v4, v5).
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text.
Generate signed JWT tokens for testing with custom headers and payloads.
Generate bcrypt password hashes with configurable salt rounds.
Generate cryptographically secure API keys in hex, base64, alphanumeric, and UUID formats.
Generate HMAC hashes with SHA-256, SHA-384, and SHA-512 algorithms.
Encrypt and decrypt text using AES-256-GCM with a password-based key.
Search engine optimization tools and analyzers.
Generate optimized meta tags including OG and Twitter Card tags.
Validate and test your robots.txt rules against specific URLs.
Generate XML sitemaps from a list of URLs with priority and frequency settings.
Extract and analyze heading structure (H1-H6) from any HTML.
Analyze keyword frequency and density in any text for SEO optimization.
Generate JSON-LD schema markup for articles, products, FAQs, local business, and more.
Preview how your page will appear in Google search results with title, URL, and meta description.
Generate optimized YouTube tags and keywords from any topic or video description to improve search visibility.
Check text for plagiarism, duplicate content, and AI-generated writing. Get an originality score with highlighted matches and AI detection analysis. 100% browser-based — your text never leaves your device.
Check your text for grammar errors, spelling mistakes, and punctuation issues. Get writing suggestions and readability analysis. 100% browser-based — your text never leaves your device.
Analyze any webpage's SEO profile — meta tags, headings, link structure, images, and technical SEO. Get a complete on-page SEO audit with actionable recommendations. Privacy-first — your data is never stored.
Text processing and conversion utilities.
Count words, characters, sentences, and paragraphs in your text instantly.
Count characters, words, sentences, and paragraphs in your text with real-time character analysis.
Generate URL-friendly slugs from any text. Supports multiple separator styles.
Generate placeholder text for your design and development projects.
Encode or decode URLs and query strings with proper percent-encoding.
Parse URL query parameters into a readable key-value table.
Find differences between two texts with line-by-line highlighting.
Convert text between uppercase, lowercase, title case, sentence case, and more.
Encode or decode Base64 text instantly in your browser.
Test regular expressions with real-time matching, syntax highlighting, and cheat sheet.
Write and preview markdown with live HTML rendering.
Write and preview markdown with live HTML rendering and syntax highlighting.
Encode or decode HTML entities (& < > ") instantly.
Sort, reverse, shuffle, deduplicate, and filter text lines.
Parse and analyze User-Agent strings to identify browsers, devices, and OS.
Sort, shuffle, deduplicate, and reverse lines of text with multiple sorting algorithms.
Strip HTML tags from content and extract clean plain text with multiple stripping modes.
Apply string operations: reverse, truncate, pad, replace, extract, and transform text.
Generate realistic placeholder data: names, emails, phone numbers, addresses, companies, and more.
Convert text to binary representation and binary back to text.
Format, beautify, and indent HTML code with configurable options.
Minify and compress HTML code by removing whitespace, comments, and unnecessary attributes.
Format, beautify, and sort CSS properties with customizable options.
Minify and compress CSS by removing whitespace, comments, and optimizing property values.
Format and beautify JavaScript code with configurable indentation.
Minify JavaScript code by removing whitespace, comments, and simplifying syntax.
Construct URLs with visual query parameter controls — add, edit, and reorder parameters with proper encoding.
Create formatted ASCII tables from pasted data for documentation and code comments.
Convert text to ASCII codes and ASCII codes back to text instantly.
Convert images to Base64 data URIs and decode Base64 strings back into viewable/downloadable images.
Parse and extract structured information from any resume or CV text — name, contact details, skills, experience, and education.
CSS generators and design utilities for developers.
Generate harmonious color palettes with monochromatic, analogous, complementary, triadic, and tetradic schemes.
Generate CSS border-radius values with a visual preview. Create smooth corners and custom shapes for your elements.
Create custom CSS box-shadow effects with a visual editor.
Create linear and radial CSS gradients with a visual editor.
Convert between CSS units: px, rem, em, pt, %, vw, vh, and more.
Create CSS grid layouts visually with customizable columns, rows, and gaps.
Create flexbox layouts visually with alignment, direction, and wrapping controls.
Create and preview CSS cubic-bezier easing curves for animations and transitions.
SQL formatting and database schema tools.
Network debugging tools for IP lookup, DNS, and more.
PDF manipulation tools for merging, converting, and editing documents.
Combine multiple PDF files into a single document. Reorder pages before merging.
Convert JPG, PNG, and WebP images to PDF documents. Arrange and resize images before conversion.
Convert PDF pages to high-quality JPG, PNG, or WebP images individually or in bulk.
Compress PDF files to reduce file size. Choose between low, medium, or high compression modes.
Split a PDF file into multiple documents. Extract specific pages or divide a PDF evenly.
Video processing tools for converting, trimming, and extracting audio.
Convert any video clip into an animated GIF. Adjust start time, duration, FPS, and size for the perfect output.
Trim and cut video files online. Select start and end points to extract the perfect clip from your video.
Extract audio from video files and convert to MP3 format. Works with MP4, WebM, MOV, and more.
XML formatting, validation, viewing, and extraction utilities.
Format, beautify, and minify XML with customizable indentation and real-time syntax highlighting.
Validate XML data and detect syntax errors with detailed error messages and line numbers.
View, parse, and explore XML data with syntax highlighting and interactive collapsible tree view.
The complete XML workspace — edit, format, minify, validate, and explore XML with interactive tree view, statistics, and syntax highlighting.
Extract all values of a specific XML tag. Enter a tag name and get all matching values in a clean list for copy or download.
A full XML workspace with Monaco editor, tree view, XPath testing, statistics, namespace explorer, XSD validation, and format conversion. All in your browser.
Random generator tools for numbers, passwords, colors, and names.
Each category hub — /json, /text, /seo, /security — groups tools by use case and provides context on when to use each one.
Many workflows span multiple tools. Use the developer workflows above to find tool chains for debugging APIs, cleaning JSON data, encoding strings, and more.
Every tool runs 100% client-side. Your data — whether JSON payloads, text content, passwords, or files — never leaves your device. No uploads, no storage, no tracking.