Developer Tools Page
Essential utilities for web developers including formatters, validators, and debugging tools.
.htaccess Generator
Generate Apache .htaccess configuration files with URL redirects, rewrites, security rules, HTTPS enforcement, caching, GZIP compression, and custom error pages. Perfect for web developers and system administrators.
API Response Formatter
Format, validate, and analyze API responses. Support for JSON, XML, and plain text with syntax highlighting, response analysis, and developer-friendly features.
API Tester & HTTP Client
Test REST APIs and HTTP endpoints with this privacy-first API testing tool. Send GET, POST, PUT, PATCH, DELETE requests with custom headers, authentication, and request bodies. Generate code in 16+ programming languages including JavaScript, Python, PHP, Go, Ruby, and more. Perfect for API development, debugging, and integration testing.
Aspect Ratio Calculator
Calculate aspect ratios from width Ć height and scale dimensions to a target while preserving the ratio. Supports common ratios (16:9, 9:16, 4:3, 1:1, 21:9, 2.39:1) for video, photo, and CSS layouts.
Barcode Generator
Generate 16 popular barcode formats including Code 128, EAN-13, UPC-A, QR Code, Data Matrix, PDF417, and more. Download or copy barcodes with customizable settings.
Chmod Calculator
Convert Unix file permissions between symbolic (rwxr-xr-x), octal (755), and checkbox-grid notation. Supports special bits (setuid, setgid, sticky). Generates the exact chmod command for your shell.
CSS Formatter / Minifier
Beautify or minify CSS code. Format CSS for readability or compress it for production use. Useful for audits, email development, and optimization.
cURL Command Generator
Generate cURL commands easily with this online cURL command builder. Configure HTTP methods, headers, authentication, request body, and advanced options to create ready-to-use cURL commands. Perfect for API testing, debugging, and sharing HTTP requests.
Fake IBAN Generator
Generate fake IBAN numbers for testing purposes. Choose from multiple countries and specify the number of IBANs to generate.
Favicon Generator
Transform text, emojis, or images into complete favicon sets. Generates all essential sizes for web browsers, mobile devices, and desktop applications. Includes ZIP download with files and ready-to-use code for HTML, React, Vue, Angular, and Next.js.
GitIgnore Generator
Generate .gitignore files for any programming language, framework, or development environment. Create customized gitignore files by combining multiple templates including Node.js, Python, Java, React, and more.
HTML Formatter / Minifier
Beautify or minify raw HTML code. Format HTML for readability or compress it for production use.
JS Formatter / Minifier
Beautify or compress JavaScript code snippets. Format JavaScript for readability or minify it for production use. Useful for code optimization and development.
JSON Diff Tool
Compare two JSON inputs to see changes and differences. Highlights additions, deletions, and modifications with clear visual indicators.
JSON Formatter
Format, validate, and beautify JSON data. Quickly view readable JSON for use in development and debugging.
JSON Schema Generator (with AI Tool-Call Builder)
Generate JSON Schema, TypeScript types, Zod schemas, and Python TypedDicts from sample JSON. Build OpenAI, Anthropic, and Gemini tool-call schemas with a visual parameter editor. 100% in your browser.
JSON to TypeScript
Convert JSON data into TypeScript interfaces or type aliases. Infers types from values, handles nested objects, arrays, and optional fields. Powered by quicktype-core.
LLM Token Counter & Cost Estimator
Count tokens for any LLM prompt and estimate API cost across GPT-5, Claude 4.7, Gemini 3, Grok 4, DeepSeek R1, and Llama 4. Visualise tokens, see context-window utilisation, and compare models side-by-side ā all in your browser.
Markdown to HTML & HTML to Markdown Converter
Convert Markdown to HTML and HTML to Markdown. Transform between formats for web publishing, documentation, and content editing. Bidirectional conversion tool.
Markdown Viewer & Preview
Preview and render Markdown content in real-time. View formatted output, export to HTML, and test your Markdown syntax with live updates and multiple theme options.
Mermaid Diagram Live Editor
Write and preview Mermaid diagrams (flowchart, sequence, gantt, class, state, ER, pie, journey, mindmap, timeline) live as you type. Pick a theme, export as SVG or PNG, copy as markdown ā all in your browser.
Meta Tag Generator
Generate essential HTML meta tags for your webpage including title, description, Open Graph, Twitter Cards, and SEO meta tags. Perfect for improving social media sharing and search engine optimization.
Mock Data Generator
Generate realistic mock data with 106+ data types across 20 categories. Create fake test data for finance, healthcare, e-commerce, education, gaming, and more. Export to JSON, CSV, SQL, XML, Firebase, InfluxDB with format-specific options. Free online mock data generator tool.
OpenGraph & Social Card Preview
Paste a URL and see how it renders on Twitter, LinkedIn, Facebook, Slack, and Discord. Audits OpenGraph + Twitter Card meta tags, flags missing fields, and shows the raw HTML head output.
Px / Em / Rem Converter
Convert between px, em, and rem values for CSS sizing. Perfect for responsive design calculations.
QR Code Generator
Generate QR codes from text or URLs with customizable size and download options. Create scannable QR codes for websites, contact info, WiFi passwords, and more.
Schema.org JSON-LD Generator
Generate ready-to-paste Schema.org JSON-LD structured data for Article, Product, LocalBusiness, FAQ, BreadcrumbList, Organization, Person, Event, Recipe, and HowTo. Improves SEO and unlocks rich results ā all in your browser.
Sitemap.xml Generator
Build a valid XML sitemap from a URL list. Set per-URL priority, change frequency, and last-modified date. Supports sitemap-index for >50 000 URLs. Validates against the sitemaps.org spec ā all in your browser.
SQL Formatter
Format and beautify SQL queries with dialect-aware formatting (standard SQL, PostgreSQL, MySQL, MariaDB, SQLite, BigQuery, Snowflake, T-SQL/SQL Server, Redshift, DB2). Indentation, keyword case, and line breaks for readability.
Text Diff Tool
Compare two blocks of text side by side and highlight differences. Perfect for comparing code, documents, or any text content.
URL Parser / Inspector
Parse any URL into its components: protocol, hostname, port, pathname, query parameters (as a table), hash fragment, and origin. Inspect and debug URLs visually.
Viewport Size Simulator
Emulate device screen sizes visually in the browser. Test responsive designs across different viewport dimensions.
Webhook Tester & Debugger
Test and debug webhooks in real-time. Generate unique webhook URLs, inspect HTTP requests with headers, body, and query parameters. Perfect for webhook development and API integration testing.