What is the CSS Unit Converter?
Convert between px, rem, em and %. The CSS Unit Converter is a free online tool that works instantly in your browser — no installation, no signup and nothing to upload. It sits alongside other Unit Converters tools on DevNibble such as Unit Converter, Data Size Converter, Length Converter.
How to use the CSS Unit Converter
- Paste the source data into the input.
- The converted output appears instantly.
- Copy or download the result.
Features
- Runs 100% in your browser — your data is never uploaded or stored.
- Free forever, with no account, no ads and no tracking.
- Copy or download your result in one click.
- Fast and responsive on desktop, tablet and mobile.
Frequently asked questions
Is the CSS Unit Converter free to use?
Yes — CSS Unit Converter is completely free with no sign-up, no ads and no limit on how many times you can use it.
Is my data private when I use the CSS Unit Converter?
Everything happens locally in your browser. Your input is never sent to a server, which makes CSS Unit Converter safe to use with private or sensitive data.
How do I use the CSS Unit Converter?
Type a value and pick its unit; CSS Unit Converter instantly shows the equivalent in every other supported unit.
Which units does the CSS Unit Converter support?
Convert between px, rem, em and %. All conversions use standard, internationally-recognised factors so the results are accurate in any direction.