Best Free Developer Tools Online

Generate unique UUID v4 and GUID strings instantly for your applications and databases.

Convert any text into a SEO-friendly URL slug. Perfect for blog posts and web pages.

Convert JSON objects into clean TypeScript interfaces or type definitions automatically.

Format and beautify your SQL queries for better readability. Supports MySQL, PostgreSQL, and more.

Compress and minify your HTML code to improve website speed. Our free online tool removes unnecessary whitespace, comments, and line breaks for faster page load times.

Parse any User Agent string to detect Browser, OS, and Engine details instantly.

Convert YAML configurations to clean JSON structures instantly. Safe & secure.

Convert JSON configurations to clean YAML structures instantly. Safe & secure.

Convert HTML special characters into safe XML entities and display tags securely online.

Generate CSS border-radius rules interactively with live shape previews and webkit/moz prefixes.

Easily create and validate cron job expressions with our interactive visual generator.

Clean and format messy XML data into a readable hierarchical structure.

Encode or decode HTML entities to prevent XSS or display special characters safely.

Generate random names for characters, personas, or test data with gender and niche options.

Transform binary code into hexadecimal format instantly. Our free online tool is perfect for low-level programming, data analysis, and memory debugging. Fast and secure.

Decode JSON Web Tokens (JWT) locally in your browser to inspect header, payload, and signature.

Secure, client-side, browser-based API credentials validators for developers. Verify your OpenAI, Gemini, DeepSeek, Stripe, and other API keys instantly.

Test your Amazon SES credentials with the send email endpoint.

Test your Anthropic Claude API key with the messages endpoint.

Convert ASCII text to binary code instantly. Our free online converter is perfect for computer science students, developers, and hobbyists. Fast, secure, and browser-based.

Convert ASCII character codes back to readable text instantly. Our free online tool makes it easy to decode ASCII sequences for development and debugging tasks.

Test your Attio API key with the records endpoint.

Transform binary code (0s and 1s) into readable ASCII text instantly. Our free online converter is fast, accurate, and works entirely in your browser. No signup required.

Convert binary numbers to decimal (Base-10) instantly. Our free online converter helps you with computer science calculations and binary data analysis in seconds.

Convert binary numbers to octal format instantly. Our free online converter provides quick and accurate base transformations for developers and technical students.

Decode binary strings into readable text instantly. Our free online tool is perfect for discovering hidden messages or debugging data streams. 100% free and secure.

Test your Brevo (Sendinblue) API key with the send email endpoint.

Test your Clearbit API key with the company enrichment endpoint.

Test your Cohere API key with the generate endpoint.

Test your Coresignal API key with the companies endpoint.

Test your Crunchbase API key with the organizations endpoint.

Format and prettify your CSS code instantly with our free online CSS Beautifier. Improve code readability, fix indentation, and organize your stylesheets for better maintenance. Fast and secure.

Compress and minify your CSS files to reduce page load times and improve website performance. Our free online tool removes unnecessary whitespace and comments instantly. Privacy-focused.

Convert CSV files to JSON format instantly. Our free online converter makes it easy to transform spreadsheet data into developer-friendly JSON code for web applications and APIs.

Test your Data Axle API key with the business lookup endpoint.

Test your Datanyze API key with the companies endpoint.

Convert decimal numbers (Base-10) to binary code (Base-2) instantly. Our free online converter is perfect for students, developers, and data analysis tasks. Fast, secure, and accurate.

Transform decimal numbers into hexadecimal format instantly. Our free online tool is perfect for web development, low-level programming, and color code analysis. Fast and private.

Convert decimal numbers to octal format instantly. Our free online converter provides quick and accurate base transformations for computer science and technical tasks. No signup required.

Convert decimal character codes back to readable text instantly. Our free online tool helps you decode numeric data streams and debug text processing tasks in your browser.

Test your DeepSeek API key with the chat completions endpoint.

Test your Demandbase API key with the accounts endpoint.

Test your Enrich API key with the person enrichment endpoint.

Test your Freshdesk API key with the tickets endpoint.

Test your FullContact API key with the person enrichment endpoint.

Test your Google Gemini API key with the generateContent endpoint.

Test your Groq API key with the chat completions endpoint.

Transform hexadecimal values into binary code instantly. Our free online HEX to Binary converter is perfect for developers, hardware engineers, and technical students. Fast and secure.

Convert hexadecimal numbers to decimal (Base-10) instantly. Our free online tool provides quick and accurate base conversions for programming and memory address analysis.

Convert hexadecimal values to octal format instantly. Our free online converter helps with computer science base transformations and data processing in your browser.

Convert hexadecimal strings back to readable text instantly. Our free online HEX to Text tool is perfect for decoding data, debugging, and discovering hidden text streams.

Test your HG Insights API key with the companies endpoint.

Format and prettify your HTML code instantly. Our free online HTML Beautifier fixes indentation, improves readability, and cleans up messy markup for better web development.

Decode HTML entities back to their original characters instantly. Our free online tool converts & and similar entities into readable text for easy debugging and content cleaning.

Encode text into HTML entities instantly for secure web display. Our free online tool protects your markup by converting special characters into safe HTML-encoded strings.

Test your HubSpot API key with the contacts endpoint.

Test your Intercom access token with the me endpoint.

Format and prettify your JavaScript code instantly. Our free online JS Beautifier improves code readability, fixes indentation, and helps you understand complex scripts easily.

Make obfuscated JavaScript code readable again instantly. Our free online DeObfuscator reverses common obfuscation techniques to help with code analysis and debugging.

Compress and minify your JavaScript files to reduce payload size and speed up your website. Our free online tool removes unnecessary code while preserving functionality.

Protect your JavaScript code by making it difficult to read and reverse-engineer. Our free online Obfuscator helps secure your intellectual property and prevent unauthorized script modification.

Edit, modify, and manage JSON data with our free online JSON Editor. Features syntax highlighting, tree view, and validation to help you structure your data perfectly.

Format and beautify your JSON data instantly for better readability. Our free online tool validates your JSON structure and provides a clean, indented view of your code.

Compress and minify your JSON data to reduce its size for web transmission. Our free online tool removes all unnecessary whitespace and comments instantly.

Convert JSON data to CSV format instantly. Our free online converter makes it easy to transform complex JSON structures into simple spreadsheet-ready tables.

Generate a JSON Schema from your JSON data automatically. Our free online tool helps you define validation rules and document your JSON structure for APIs.

Convert JSON data into readable plain text instantly. Our free online tool is perfect for extracting values and creating human-readable documentation from raw data.

Convert JSON data to Tab-Separated Values (TSV) format instantly. Our free online converter helps you prepare data for Excel and other spreadsheet applications.

Convert JSON data to XML format instantly. Our free online tool handles nesting and attributes to ensure a clean transformation for legacy system compatibility.

Validate your JSON data for syntax errors and structural integrity instantly. Our free online tool helps you catch bugs and ensure your JSON is RFC-compliant.

Free json viewer tool to process your data instantly with privacy-friendly browser-based workflows.

Test your LeadGenius API key with the companies endpoint.

Test your Leadspace API key with the contacts endpoint.

Test your Loops API key with the contacts endpoint.

Test your Lusha API key with the contacts endpoint.

Test your Mailgun API key with the messages endpoint.

Test your Mattermark API key with the companies endpoint.

Test your Melissa API key with the address verification endpoint.

Convert octal numbers to binary code instantly. Our free online converter provides fast and accurate base transformations for computer science students and developers.

Convert octal numbers to decimal (Base-10) instantly. Our free online tool makes it easy to transform numeric bases for programming and mathematical calculations.

Transform octal values into hexadecimal format instantly. Our free online converter is perfect for low-level programming and memory address transformations.

Convert octal character codes back to readable text instantly. Our free online tool helps you decode data streams and debug text processing tasks in your browser.

Test your OpenAI API key with the models endpoint.

Test your People Data Labs API key with the person enrichment endpoint.

Test your Pipedrive API token with the deals endpoint.

Test your Pipl API key with the search endpoint.

Test your Postmark Server Token with the email sending endpoint.

Test your Resend API key with the emails endpoint.

Test your SendGrid API key with the mail send endpoint.

Test your Snov.io API key with the leads endpoint.

Test your SparkPost API key with the transmissions endpoint.

Test your Stripe API key with the charges endpoint.

Convert plain text into ASCII character codes instantly. Our free online tool provides decimal ASCII values for every character in your input string. Fast and secure.

Translate text into binary code (0s and 1s) instantly. Our free online converter is perfect for learning how computers represent data and creating secret binary messages.

Convert text characters into their decimal numeric equivalents instantly. Our free online tool is useful for debugging character encoding and understanding data representations.

Convert plain text into hexadecimal format instantly. Our free online tool provides a clean hex representation of your input string for development and data analysis.

Convert text into octal numeric values instantly. Our free online converter provides base-8 representations for every character in your text for technical analysis.

Convert Tab-Separated Values (TSV) into JSON format instantly. Our free online tool makes it easy to transform structured data for web applications and API development.

Test your Twilio Account SID and Auth Token with the messages endpoint.

Convert XML documents to JSON format instantly. Our free online converter handles complex XML hierarchies to provide clean, developer-friendly JSON output for web apps.

Test your Zendesk API token with the tickets endpoint.

Test your ZoomInfo API key with the contacts endpoint.

Encode and decode Base64 strings instantly with our free online tool. Perfect for web development, data transmission, and working with binary data in text format.

Create beautiful CSS gradients for your web projects.

Generate CSS box shadows and text shadows for modern web design.

Format and beautify HTML, CSS, JavaScript, and SQL code.