Free Online Developer Tools

18 tools — all free, no signup required

Essential utilities for web developers and programmers.

Color Contrast Checker

Check WCAG accessibility compliance for text and background color combinations.

Countdown Timer to Date

Countdown to any future date and time with days, hours, minutes, and seconds display.

Cron Expression Parser

Parse and explain cron expressions in plain English with next scheduled run times.

CSS Gradient Generator

Generate linear, radial, and conic CSS gradients with live preview and one-click copy.

Diff Checker

Compare two texts side by side with highlighted differences.

Electronic Signature Maker

Draw or type a signature and embed it into a PDF document — all in your browser.

HTML Entity Encoder/Decoder

Convert special characters to HTML entities and decode entities back to characters.

Internet Speed Test

Measure download, upload, and ping using browser-based network tests.

JWT Decoder

Decode JWT tokens to view header and payload as formatted JSON.

Markdown Preview

Write Markdown on the left, see rendered HTML preview on the right.

Online Stopwatch

Precise stopwatch with lap tracking and per-lap split times.

Online Timer

Countdown timer with presets, custom time, progress ring, and audio alert.

Pomodoro Timer

Focus timer with work/break intervals, session tracking, and customizable durations.

Regex Tester

Test regex patterns with real-time match highlighting and capture group display.

Typing Speed Test

Test your typing speed and accuracy with WPM tracking and real-time character feedback.

URL Encoder/Decoder

Encode or decode URL components with percent-encoding and swap workflow.

What Is My IP + Device Info

View your IP address, user agent, browser, platform, and device details instantly.

YAML ↔ JSON Converter

Convert YAML to JSON and JSON to YAML instantly with error highlighting and download.

About Developer Tools

Essential utilities for web developers and programmers — format JSON, encode/decode Base64, generate regex patterns, diff text, preview code, and more. These tools integrate into your workflow without requiring extensions or desktop apps.

Built by developers for developers, each tool focuses on one task and does it well. Whether you're debugging API responses, formatting configuration files, or testing regular expressions, everything runs in your browser with full privacy.

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