CSS Prefixer - Add Vendor Prefixes to CSS Online

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.

How to Use the CSS Prefixer

Follow these steps to add vendor prefixes to your CSS. Each step uses the actual buttons and panels on this page.

Paste, Upload, or Load Sample

Paste CSS into the left Input CSS panel, or click Upload to load a .css file. Click Sample to see example telecomm subscriber dashboard styles with properties that need prefixes. Example:

.subscriber-card {
  display: flex;
  transform: translateY(-2px);
  transition: all 0.3s ease;
}

View Prefixed Output

The right Prefixed CSS panel shows output with -webkit-, -moz-, -ms-, and -o- prefixes where needed. Properties like flex, transform, and transition get all necessary prefixed versions for cross-browser support.

Copy or Download

Click Copy to copy to clipboard, or Download to save as .css. Use Clear to start fresh. All processing runs in your browser.

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: