.webp File Extension

What kind of file is a .webp?

A .webp file is a WebP raster image. It uses the image/webp MIME type and can hold a still image or animation. WebP supports lossy and lossless compression, full alpha transparency, color profiles, and EXIF or XMP metadata.¹

The identifying header begins with RIFF, a four-byte little-endian size, and the form type WEBP. In hexadecimal, that pattern is 52 49 46 46 ?? ?? ?? ?? 57 45 42 50. A following chunk may identify lossy VP8 , lossless VP8L, or extended VP8X data.¹

How do I open a .webp on my computer?

The simplest viewer is a current web browser. Chrome, Edge, Firefox, Opera, and Safari display WebP directly.² Drag the file into a browser window if your desktop's default photo app does not recognize it.

For editing and conversion:

• Adobe Photoshop 23.2 or later can open, create, edit, and save WebP without a plug-in.³
• GIMP and many current image editors support WebP still images and common WebP export options.
• Google's dwebp command-line tool decodes WebP, while cwebp creates WebP files from formats such as PNG and JPEG.⁴

Animated files may appear as one frame in software that supports still WebP but not animation. Keep untrusted image software updated because malformed files can still exploit decoder bugs.

Poly support for .webp

Poly gives WebP images thumbnails, an in-app preview, supported EXIF metadata, visual search, and agent understanding. You can find an image by filename or appearance, and the original file opens in the image viewer. Animated WebP can play there when the browser supports it.

Thumbnails, visual indexing, and agent understanding use a representative still rather than the complete animation. Text drawn into an ordinary WebP is not indexed as document text. If important information appears only in later frames, export those frames or use a supported video format.

History of .webp

Google announced WebP as a developer preview on September 30, 2010. The initial format applied VP8 intra-frame coding to still images. Lossless compression and alpha transparency followed in 2011.⁵⁶

WebP's formal media-type registration came much later. RFC 9649, published in November 2024, documents the container and lossless bitstream and registers .webp with image/webp. The RFC is Informational rather than an Internet Standards Track specification.¹

Working with .webp and alternatives

WebP uses 8-bit image data.¹ It is flexible for websites because one suffix covers photographs, transparent graphics, and animation.

In Google's reproducible study, WebP files were 25% to 34% smaller than JPEG at equivalent or slightly better SSIM across its tested datasets and settings.⁷ Treat that as a benchmark, not a guarantee. Compare your own source images at the quality you need.

Conversion can discard animation timing, transparency, color profiles, or metadata. Converting a lossy WebP to PNG prevents another lossy save but cannot restore discarded detail. Keep the original until you have checked the converted pixels, frames, and metadata.