Developer

Learn how AI language models work. Visualize tokenization, simulate temperature sampling, count tokens, build prompts. Interactive LLM tutorial and prompt engineering helper

Generate mock API responses with fake JSON data. Create realistic REST API test data. Free mock server response generator for developers

Calculate Unix/Linux file permissions. Convert between symbolic (rwx) and numeric (755, 644) notation. Free chmod permission calculator online

Format and beautify JSON, XML, CSS, HTML, JavaScript, SQL code. Auto-indent and syntax highlight. Free online code beautifier and formatter

Debug CORS issues, analyze headers, generate server configurations. Support for Express, Nginx, Apache, Django, Flask, Spring Boot. Learn CORS concepts. Free online CORS tester

Build docker-compose.yml files visually. Add MySQL, PostgreSQL, Redis, MongoDB services. Free online Docker Compose YAML generator

Build Git commands interactively with options and flags. Learn branching, merging, rebasing with visualizations. Quick recipes for common Git workflows

Generate conventional commit messages following Angular, Conventional Commits standards. Create semantic git commits. Free commit message builder

Generate .gitignore files for any project. Templates for Node, Python, Java, Go, React, Vue, and more. Free online gitignore generator

Complete list of HTTP status codes with descriptions and examples. Learn 200, 301, 404, 500 error codes. Free HTTP response code reference guide

Generate JSON Schema from example JSON data automatically. Create validation schemas for APIs. Free online JSON Schema builder for developers

Generate TypeScript interfaces from JSON data. Support for nested objects, arrays, optional properties. Free online JSON to TS interface generator

Test JSONPath expressions with live results. Query JSON documents with JSONPath syntax. Free online JSONPath evaluator and debugger

Generate JSON Web Tokens with custom claims. Support for HS256, HS384, HS512 algorithms. Set expiration, issuer, subject, audience. Free online JWT generator

Decode and inspect JWT tokens. View header, payload, signature. Verify JWT expiration and claims. Free online JSON Web Token decoder and debugger

Test and debug regular expressions with real-time matching. Regex pattern builder with explanation. Free online regex tester for JavaScript, Python, PHP

Format and beautify SQL queries with syntax highlighting. Support for MySQL, PostgreSQL, SQL Server. Free online SQL formatter and pretty printer

Run SQL queries in your browser with SQLite. Import CSV files, create tables, export results. Free online SQL editor and database sandbox

Generate valid test credit card numbers for development. Visa, Mastercard, Amex, Discover. Luhn-valid numbers for payment testing. Free fake card generator

Parse and analyze browser User-Agent strings. Detect browser, OS, device type from UA. Free online User-Agent decoder and analyzer

Test XPath expressions on XML documents with live results. Debug XPath queries for web scraping. Free online XPath evaluator and validator

Transform XML documents using XSLT stylesheets. Live preview of rendered HTML. Built-in templates for tables, cards, lists. Free online XSLT processor