CSS Prefixer
Automatically add vendor prefixes to your CSS
Input CSS
Prefixed CSS
What is a CSS Prefixer?
Browser vendors add experimental CSS features using prefixes like -webkit-, -moz-, -ms-, and -o-. Without these prefixes, your modern CSS won't work in older browsers. This CSS prefixer automatically adds all necessary vendor prefixes to ensure your CSS (Cascading Style Sheets) works across different browsers and versions.
According to MDN Web Docs, vendor prefixes are critical for cross-browser compatibility. Our tool follows the Can I Use database to determine which properties need prefixes, ensuring your styles work on Chrome, Firefox, Safari, Edge, and older browser versions.
Everything runs locally in your browser. No uploads, no servers – just paste your CSS and get prefixed output instantly.
Why Use This CSS Prefixer
Automatic Detection
Automatically identifies properties that need vendor prefixes. No need to memorize which CSS features require prefixes – we handle it all.
All Major Prefixes
Adds -webkit-, -moz-, -ms-, and -o- prefixes where needed. Covers Chrome, Firefox, Safari, Edge, Opera, and their older versions.
Preserves Structure
Maintains your CSS structure, comments, and formatting. Only adds prefixes – your code organization stays intact.
Flexbox & Grid Support
Special handling for Flexbox and CSS Grid properties. These modern layout features require extensive prefixing for older browsers.
Animation & Transform
Prefixes animations, transforms, and transitions automatically. Ensures your animations work smoothly across all browsers.
Instant Preview
See prefixed output as you type. Real-time processing shows exactly what your CSS will look like with all vendor prefixes.
How to Add Vendor Prefixes
Add Your CSS
Paste your CSS into the left editor, or click "Upload" to load a .css file. You can also try the "Sample" button to see example prefixing. Works with any modern CSS including Flexbox, Grid, animations, and transforms.
Automatic Prefixing
Prefixes are added instantly as you type or paste. The tool detects properties like transform, animation, flex, and many others that need vendor prefixes. Each property gets all necessary prefixed versions.
Copy or Download
Click "Copy" to grab the prefixed CSS, or "Download" to save it as a file. The output includes all vendor prefixes needed for maximum browser compatibility. All processing is instant and local.
When You'd Use This
Cross-Browser Compatibility
Building a site that needs to work on older browsers? Add vendor prefixes to ensure modern CSS features like Flexbox and Grid work everywhere. Essential for enterprise projects with legacy browser support.
Quick Prototyping
Testing CSS animations or transforms across browsers? Prefix your code first to avoid browser-specific issues. Saves time when you're iterating quickly on designs.
Legacy Projects
Maintaining older projects that still support IE11 or older Chrome versions? Add prefixes to new CSS features before deploying. Prevents breaking existing browser support.
Learning CSS
Understanding which CSS properties need vendor prefixes? Use this tool to see which features require prefixing. Educational for developers learning about browser compatibility.
Common Questions
What are vendor prefixes?
Vendor prefixes are browser-specific CSS property prefixes like -webkit-, -moz-, -ms-, and -o-. Browsers use them to implement experimental or non-standard CSS features before they become official standards.
Do I still need prefixes in modern browsers?
For cutting-edge features, yes. While modern browsers support most standard CSS, some newer properties and older browser versions still require prefixes. Check Can I Use for specific property support.
Which properties need prefixing?
Common ones include transform, transition, animation, flex properties, border-radius (older browsers), box-shadow, and many others. Our tool automatically detects these based on MDN standards.
What's the order of prefixed properties?
Prefixed properties should come before the standard property. Our tool follows this convention: vendor prefixes first (-webkit-, -moz-, -ms-, -o-), then the standard unprefixed property last.
Will this make my CSS file larger?
Yes, adding vendor prefixes increases file size. However, the trade-off is browser compatibility. For production, use this with minification and consider using Autoprefixer in your build process.
Is my CSS data safe?
Absolutely. All processing happens in your browser using JavaScript. Your CSS never leaves your computer – no server uploads, no data storage, completely private.
Related CSS Tools
Prefixing is just one part of CSS development. Here are other tools that might help: