What is a WEBP File?

What Is a WebP File?

WebP is an image file format created by Google, first released in 2010. It was designed specifically for web use — to deliver images with smaller file sizes than JPG and PNG while maintaining comparable or superior visual quality.

The file extension is .webp.

How Does WebP Work?

WebP uses a combination of advanced compression algorithms borrowed from the VP8 video codec. It can operate in two modes:

• Lossy WebP: Similar to JPG — discards some imperceptible detail to achieve very small file sizes. Typically 25–34% smaller than equivalent JPG.
• Lossless WebP: Similar to PNG — stores every pixel exactly. Typically 26% smaller than equivalent PNG.

WebP also supports transparency (like PNG) and animation (like GIF) in both modes.

WebP Browser Support

All modern browsers support WebP. Internet Explorer does not, but IE has a global usage rate below 1%.

Should You Use WebP for Your Website?

Yes — if your website serves a modern audience. Switching from JPG and PNG to WebP typically reduces total page image weight by 25–40%, directly improving load speed and Core Web Vitals scores.

How to convert: Use our free PNG to WEBP converter to convert your site images in seconds.

The Technical Story

WebP was developed by Google after they acquired On2 Technologies in 2010. On2's VP8 video codec technology was adapted for still images, producing a format that outperformed existing image codecs.

The key technical innovations: WebP lossy mode uses transform-domain quantization similar to what VP8 uses for video — a more sophisticated approach than JPEG's DCT (Discrete Cosine Transform). For lossless mode, WebP uses a predictive algorithm that's more efficient than PNG's filtering.

The result: smaller files at equivalent quality, or better quality at equivalent file size.

Browser and Platform Support in 2025

WebP is universally supported in modern browsers:

• Chrome: since 2010
• Firefox: since 2019
• Edge: since 2018
• Safari: since 2020 (iOS 14 and macOS Big Sur)
• Opera: since 2011

Native app support:

• Android: native support in the OS image frameworks
• iOS: limited native support — requires specific APIs or conversion

For web development, WebP is safe to serve to any modern audience. For image files shared person-to-person (emailed, sent via messaging apps), JPG or PNG remains more compatible.

WebP Features

Lossy compression: Similar to JPG but more efficient. For photos, lossy WebP at quality 80 is visually similar to JPG at quality 90 but significantly smaller.

Lossless compression: Preserves every pixel exactly, like PNG. WebP lossless is typically 25–35% smaller than equivalent PNG.

Transparency: WebP supports alpha channel transparency in both lossy and lossless modes. This makes it a viable replacement for PNG in web contexts.

Animation: WebP supports animation, like GIF but with dramatically better compression and quality. Although video tags with WebM are often more appropriate for long animations.

Practical Impact on Web Performance

The impact of switching to WebP is concrete. A typical web page with 10 images:

• Before: 10 JPGs averaging 300 KB each = 3 MB of image data
• After: 10 WebPs averaging 200 KB each = 2 MB of image data

A 33% reduction in image payload. On a 10 Mbps mobile connection, this is approximately 0.8 seconds of load time saved just from images. For Largest Contentful Paint (Google's primary page speed metric), this difference is often the gap between a "Good" and "Needs Improvement" score.

Converting Images to WebP

weFixPDF's PNG to WebP tool converts PNG files to lossless WebP in your browser — files are never uploaded to a server. For JPG-to-WebP conversion (lossy), Squoosh (Google's browser-based image optimizer) is a good option. For batch conversion in development workflows, the Sharp library (Node.js) handles WebP conversion programmatically.