Online Developer Tools & Utilities

Free online utilities for developers, including JSON formatters, text tools, and testing utilities.

Keyboard Tester

Free online Keyboard Tester. Check if your keys are working, test for ghosting, and view key codes. Works on Mac & Windows.

Popular

Typing Speed Test

Run a free typing speed test with time, words, and quote modes. Track net WPM, raw WPM, CPM, error rate, history trends, and challenge links.

New

Reaction Time Test

Run a gamer-focused reaction time test with Classic, Focus, Distraction, and Stamina modes. Track percentile, consistency, integrity flags, and challenge links.

New

JSON Formatter & Validator

Instantly format, validate, and minify your JSON data.

Top

What is my Screen Resolution?

Instantly detect your screen and browser dimensions.

Regex Testing Tool

Test regular expressions live against sample text with instant match output.

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Base64 + Hashing Tool

Encode/decode Base64 and generate SHA-256 hashes in your browser.

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Markdown Preview Tool

Preview Markdown output instantly while you write.

New

Code Snippet Formatting Tool

Normalize indentation and clean pasted code snippets quickly.

New

JWT Decoder & Validator

Structural decoding and claim validation for JWT tokens with no server upload.

New

Cron Expression Builder

Compose, validate, and preview cron schedules before deploying jobs.

New

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Essential Developer Utilities and Formatters

In modern web and software development, efficiency is everything. Our collection of online developer tools is engineered to help programmers, QA testers, and technical professionals validate data, test hardware, and debug issues without leaving the browser.

Formatting and Validating JSON

JSON (JavaScript Object Notation) is the ubiquitous data format for APIs and configuration files. However, raw JSON is often minified and incredibly difficult for humans to read. A single missing comma or bracket can crash an entire application.

Our JSON Formatter is an essential utility that instantly parses, indents, and color-codes your JSON data. It helps you quickly identify syntax errors and format complex nested objects into a readable structure. Because privacy is paramount, all parsing happens locally on your device—your sensitive API payloads are never sent to a server.

Testing Hardware Inputs

For developers building interactive applications or gamers debugging their peripherals, ensuring every keypress registers correctly is vital. Ghosting or broken switches can lead to frustrating UX bugs.

Use our Keyboard Tester to visually verify every key on your keyboard. It supports multiple layouts (ANSI, ISO) and includes an integrated mouse button tester, making it a comprehensive diagnostic tool for your input devices.

Responsive Design and Viewport Metrics

Building responsive websites requires a deep understanding of the client's display capabilities. The Screen Resolution Checker provides immediate feedback on the user's viewport dimensions, screen resolution, and device pixel ratio. This ensures your CSS media queries and canvas elements render crisply on high-DPI (Retina) displays.

We are continually expanding this section with robust, secure, and lightning-fast developer tools designed to streamline your daily workflows.