All Developer Tools
100+ 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.
Most Searched Tools
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.
Developer Workflows
Common developer tasks that span multiple tools. Use these workflow clusters to move efficiently through your daily debugging, data transformation, and security testing routines.
Debug APIs
Inspect and test HTTP endpoints, WebSocket connections, and API responses. Build requests, check status codes, and convert curl commands.
Clean & Transform JSON Data
Format, validate, and compare JSON documents. Convert between JSON and YAML, CSV, XML, or TOML. Query data with JSONPath expressions.
Encode & Decode Strings
Encode and decode data for safe transmission. Convert between Base64, percent-encoded URLs, and HTML entities. Transform text between naming conventions.
Test Authentication Tokens
Decode, inspect, and generate JWT tokens. Hash passwords with bcrypt, generate HMAC signatures, and create secure random UUIDs.
Convert File Formats
Transform data between common developer formats. Convert images between JPEG, PNG, WebP, and AVIF. Merge PDFs or convert JPG to PDF.
Common Developer Questions
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
Tool Categories
Browse by category to find the right utility for your task. Each category groups tools by their primary function.
AI
View allAI developer tools for prompt engineering and token management.
Prompt Formatter
Format and structure AI prompts with markdown preview and template variables.
AI Token Counter
Count tokens for GPT-4, GPT-3.5, Claude, and Llama models.
AI Response Comparator
Compare AI model outputs side by side for quality evaluation.
JSON Schema to Prompt
Convert JSON schemas into structured AI prompts for structured output generation.
AI Regex Generator
Generate regular expressions from natural language descriptions.
AI JSON Explainer
Get a plain-English explanation of any JSON structure, including fields, types, and nesting.
AI SQL Query Builder
Build SQL queries from natural language descriptions using a pattern-based engine.
API
View allAPI testing and HTTP debugging utilities.
REST API Client
Send HTTP requests (GET, POST, PUT, DELETE) and inspect responses from your browser.
WebSocket Tester
Connect to WebSocket endpoints, send messages, and inspect frames.
HTTP Status Code Reference
Searchable reference of all HTTP status codes with descriptions and use cases.
Request Builder
Build HTTP requests interactively and generate code snippets in multiple languages.
curl to Fetch Converter
Convert curl commands to JavaScript fetch, Python requests, and more.
OpenAPI Validator
Validate OpenAPI 3.x and Swagger 2.0 specifications for correctness.
Mock API Generator
Generate mock API responses from JSON schemas for rapid development.
Fake Data Generator
Generate realistic fake data including names, emails, phone numbers, addresses, and more.
Date & Time
View allDate and time conversion utilities.
Unix Timestamp Converter
Convert between Unix timestamps and human-readable dates instantly.
Age Calculator
Calculate exact age from date of birth in years, months, days, hours, and minutes.
Date Difference
Calculate the exact difference between two dates in years, months, days, and more.
Cron Expression Generator
Generate and explain cron schedules with a visual builder.
Image
View allImage processing and QR code tools.
QR Code Generator
Create custom QR codes with colors, logos, and sizes.
Image Optimizer
Compress images in your browser reducing file size without losing quality.
Image Compressor
Compress images with precise quality control. Reduce file size by adjusting quality, removing metadata, and more.
Image Converter
Convert between image formats including JPEG, PNG, WebP, and AVIF.
Color Converter
Convert HEX, RGB, HSL, and named colors instantly with a color picker.
SVG Optimizer
Minify and optimize SVG files by removing unnecessary data.
Base64 Image Encoder
Encode images to Base64 data URIs for embedding in HTML or CSS.
JSON
View allJSON formatting, validation, and transformation tools.
JSON Formatter & Validator
Format, validate, and minify JSON with real-time syntax checking.
JSON Compare
Compare two JSON files side by side with real-time diff highlighting.
CSV to JSON Converter
Convert CSV data to JSON format with support for headers and custom delimiters.
YAML to JSON Converter
Convert YAML data to JSON format with support for complex nested structures.
JSON Validator
Validate JSON data and detect syntax errors with detailed error messages and line numbers.
JSON to TOML Converter
Convert JSON data to TOML format for configuration files.
JSON Schema Generator
Generate JSON Schema (draft-07) from sample JSON data automatically.
JSON to TypeScript Interface Generator
Convert JSON to TypeScript interfaces instantly. Generate typed interfaces from JSON samples for type-safe development.
JSON to Python Dataclass Generator
Convert JSON to Python dataclasses instantly. Generate typed Python classes from JSON samples for type-safe data handling.
JSON to Java Class Generator
Convert JSON to Java POJO classes instantly. Generate Java records or classes with getters and fields from JSON samples.
JSON to C# Class Generator
Convert JSON to C# classes instantly. Generate C# POCO classes with properties and attributes from JSON samples.
JSON to Go Struct Generator
Convert JSON to Go struct types instantly. Generate Go structs with JSON tags from JSON samples for Go development.
JSON to GraphQL Type Generator
Convert JSON to GraphQL schema types instantly. Generate GraphQL type definitions from JSON samples for your API schema.
JSON ↔ XML Converter
Convert between JSON and XML formats bidirectionally.
JSON Path Tester
Test JSONPath expressions against JSON data and see matched results.
JSON Node Value Extractor
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
View allMath calculators and number converters.
Unit Converter
Convert length, weight, temperature, area, and volume units.
Number Base Converter
Convert between binary, octal, decimal, and hexadecimal number systems.
Percentage Calculator
Calculate percentages easily with three common modes.
Chmod Calculator
Convert Unix file permissions between numeric and symbolic formats.
Random Number Generator
Generate cryptographically secure random numbers with custom ranges and count.
Scientific Calculator
Perform scientific calculations with trigonometric, logarithmic, and exponential functions.
Next.js
View allNext.js utility tools for configuration and routing.
App Router Path Builder
Visual builder for Next.js App Router routes including groups and parallel routes.
Middleware Matcher Builder
Build and test Next.js middleware config matcher patterns visually.
next.config Visualizer
Parse and explore next.config.js/ts options with descriptions and defaults.
Image Optimization Calculator
Calculate optimal image dimensions, sizes, and srcset for Next.js Image.
Route Handler Generator
Generate Next.js App Router API route boilerplate with type safety.
Security
View allSecurity and cryptography utilities.
JWT Decoder
Decode and inspect JWT tokens instantly.
Password Generator
Generate strong, secure random passwords with customizable options.
UUID Generator
Generate UUID v4 identifiers instantly.
UUID Validator
Validate UUID strings and identify the version (v1, v2, v3, v4, v5).
Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text.
JWT Generator
Generate signed JWT tokens for testing with custom headers and payloads.
Bcrypt Hash Generator
Generate bcrypt password hashes with configurable salt rounds.
HMAC Generator
Generate HMAC hashes with SHA-256, SHA-384, and SHA-512 algorithms.
AES Encrypt & Decrypt
Encrypt and decrypt text using AES-256-GCM with a password-based key.
SEO
View allSearch engine optimization tools and analyzers.
Meta Tag Generator
Generate optimized meta tags including OG and Twitter Card tags.
Robots.txt Tester
Validate and test your robots.txt rules against specific URLs.
Sitemap Generator
Generate XML sitemaps from a list of URLs with priority and frequency settings.
Heading Analyzer
Extract and analyze heading structure (H1-H6) from any HTML.
Keyword Density Analyzer
Analyze keyword frequency and density in any text for SEO optimization.
Schema Markup Generator
Generate JSON-LD schema markup for articles, products, FAQs, local business, and more.
SERP Preview Tool
Preview how your page will appear in Google search results with title, URL, and meta description.
Text
View allText processing and conversion utilities.
Word Counter
Count words, characters, sentences, and paragraphs in your text instantly.
Character Counter
Count characters, words, sentences, and paragraphs in your text with real-time character analysis.
Slug Generator
Generate URL-friendly slugs from any text. Supports multiple separator styles.
Lorem Ipsum Generator
Generate placeholder text for your design and development projects.
URL Encode/Decode
Encode or decode URLs and query strings with proper percent-encoding.
URL Query Parser
Parse URL query parameters into a readable key-value table.
Diff Checker
Find differences between two texts with line-by-line highlighting.
Case Converter
Convert text between uppercase, lowercase, title case, sentence case, and more.
Base64 Encode/Decode
Encode or decode Base64 text instantly in your browser.
Regex Tester
Test regular expressions with real-time matching, syntax highlighting, and cheat sheet.
Markdown Preview
Write and preview markdown with live HTML rendering.
Markdown Editor
Write and preview markdown with live HTML rendering and syntax highlighting.
HTML Entities Converter
Encode or decode HTML entities (& < > ") instantly.
Text Sorter
Sort, reverse, shuffle, deduplicate, and filter text lines.
User-Agent Parser
Parse and analyze User-Agent strings to identify browsers, devices, and OS.
HTML Formatter
Format, beautify, and indent HTML code with configurable options.
HTML Minifier
Minify and compress HTML code by removing whitespace, comments, and unnecessary attributes.
CSS Formatter
Format, beautify, and sort CSS properties with customizable options.
CSS Minifier
Minify and compress CSS by removing whitespace, comments, and optimizing property values.
JavaScript Formatter
Format and beautify JavaScript code with configurable indentation.
JavaScript Minifier
Minify JavaScript code by removing whitespace, comments, and simplifying syntax.
URL Builder
Build, parse, and manipulate URLs with query parameters visually.
ASCII Table Generator
Create formatted ASCII tables from pasted data for documentation and code comments.
ASCII Converter
Convert text to ASCII codes and ASCII codes back to text instantly.
Image to Base64 & Base64 to Image
Convert images to Base64 data URIs and decode Base64 strings back into viewable/downloadable images.
Design
View allCSS generators and design utilities for developers.
Color Palette Generator
Generate harmonious color palettes with monochromatic, analogous, complementary, triadic, and tetradic schemes.
Border Radius Generator
Generate CSS border-radius values with a visual preview for each corner.
Box Shadow Generator
Create custom CSS box-shadow effects with a visual editor.
CSS Gradient Generator
Create linear and radial CSS gradients with a visual editor.
CSS Unit Converter
Convert between CSS units: px, rem, em, pt, %, vw, vh, and more.
CSS Grid Generator
Create CSS grid layouts visually with customizable columns, rows, and gaps.
Flexbox Generator
Create flexbox layouts visually with alignment, direction, and wrapping controls.
Cubic Bezier Generator
Create and preview CSS cubic-bezier easing curves for animations and transitions.
Database
View allSQL formatting and database schema tools.
Network
View allNetwork debugging tools for IP lookup, DNS, and more.
PDF manipulation tools for merging, converting, and editing documents.
PDF Merge
Combine multiple PDF files into a single document. Reorder pages before merging.
JPG to PDF Converter
Convert JPG, PNG, and WebP images to PDF documents. Arrange and resize images before conversion.
PDF to JPG Converter
Convert PDF pages to high-quality JPG, PNG, or WebP images individually or in bulk.
PDF Compressor
Compress PDF files to reduce file size. Choose between low, medium, or high compression modes.
PDF Splitter
Split a PDF file into multiple documents. Extract specific pages or divide a PDF evenly.
Video
View allVideo processing tools for converting, trimming, and extracting audio.
Video to GIF Converter
Convert any video clip into an animated GIF. Adjust start time, duration, FPS, and size for the perfect output.
Video Trimmer & Cutter
Trim and cut video files online. Select start and end points to extract the perfect clip from your video.
Video to MP3 Converter
Extract audio from video files and convert to MP3 format. Works with MP4, WebM, MOV, and more.
XML
View allXML formatting, validation, viewing, and extraction utilities.
XML Formatter & Validator
Format, beautify, validate, and minify XML with real-time syntax checking.
XML Validator
Validate XML data and detect syntax errors with detailed error messages and line numbers.
XML Viewer + Tree View
View, parse, and explore XML data with syntax highlighting and interactive collapsible tree view.
XML Editor Online
Edit, write, and preview XML with real-time syntax highlighting, line numbers, and live formatted preview.
XML Tag Value Extractor
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.
Random
View allRandom generator tools for numbers, passwords, colors, and names.
How to Use These Tools
Start with Hubs
Each category hub — /json, /text, /seo, /security — groups tools by use case and provides context on when to use each one.
Use Tools in Sequence
Many workflows span multiple tools. Use the developer workflows above to find tool chains for debugging APIs, cleaning JSON data, encoding strings, and more.
Privacy by Design
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.