What is the standard base font size for REM calculations?

The default base font size in browsers is 16px, which is the standard for REM calculations. However, some websites use different base sizes (like 10px for easier math). Our converter lets you customize the base size to match your project settings.

Why should I use REM instead of pixels?

REM units are relative to the root font size, making your design more accessible and responsive. Users who change their browser font size for readability will see your design scale appropriately, unlike fixed pixel values.

How do I convert Hex colors to RGB?

Simply paste your hex color code (with or without the # symbol) into our converter. We will instantly show you the RGB values along with CSS-ready formats for both hex and rgb() syntax that you can copy directly into your code.

What format does the Unix timestamp converter use?

We convert Unix timestamps (seconds since January 1, 1970) to human-readable dates. We support both seconds and milliseconds formats and display results in your local timezone as well as UTC for clarity.

Online Unit Converter Tool for Developers

How the Unit Converter Works

The SimpleTaskTools Unit Converter is a specialized collection of conversion tools designed specifically for web developers and designers. Convert between common units used in CSS, design systems, and programming with instant, real-time results. All conversions happen locally in your browser for maximum speed and privacy.

Pixels to REM Conversion

REM units are essential for building accessible, responsive websites. Unlike fixed pixel values, REM units scale with the user browser font-size preferences, making your designs more accessible. Our converter lets you specify a custom base font-size (defaulting to the browser standard of 16px) and instantly see the REM equivalent of any pixel value. The quick reference grid helps you learn common conversions at a glance.

Hex to RGB and HSL Conversion

Working with colors in CSS often requires converting between different formats. Our hex color converter translates hexadecimal color codes (#RRGGBB or #RGB shorthand) into both RGB and HSL values. RGB values are perfect for JavaScript canvas operations and older CSS, while HSL is often more intuitive for adjusting colors programmatically. The live color preview helps you visualize your colors as you work.

Unix Timestamp to Date Conversion

Unix timestamps are the universal time format in programming, representing seconds (or milliseconds) since January 1, 1970. Our converter handles both formats automatically, detecting whether your input is in seconds or milliseconds. Convert any timestamp to a human-readable local date/time or ISO 8601 format for API work. The Now button lets you quickly grab the current timestamp for testing.

Developer-Focused Design

Every tool in this converter suite is built with developers in mind. Copy buttons on every output let you quickly transfer values to your code. Monospace fonts ensure digit alignment for easy reading. Input fields accept keyboard entry for fast workflows, and all results update in real-time as you type - no need to click a convert button.

Privacy and Performance

Like all SimpleTaskTools utilities, this converter runs entirely in your browser. There are no server calls, no data collection, and no tracking. Your color codes, timestamps, and pixel values remain completely private. The client-side architecture also means instant results with zero latency, regardless of your internet connection speed.

Developer Unit Converter - PX to REM, Hex to RGB, Unix to Date

Quick Reference (base 16px)