WEBP MIME Type

About WebP image files

Supported by every current browser, usually 25–35% smaller than JPEG at similar quality, with transparency and animation. Serve it with <picture> and a JPEG or PNG fallback if you still support very old Safari versions (before 14).

File signature

WEBP files start with "RIFF", then "WEBP" at byte 8. The extension and the type a browser reports for an upload both come from the file name, so check these bytes on the server before trusting a file.

Serve .webp with the right Content-Type

Content-Type: image/webp

image/webp webp;

AddType image/webp .webp

@webp path *.webp
header @webp Content-Type "image/webp"

curl -sI https://example.com/file.webp | grep -i '^content-type'
# Content-Type: image/webp

Set the type in code

res.set('Content-Type', 'image/webp');
// Or make the browser download it:
res.attachment('file.webp');

import mimetypes

mimetypes.add_type('image/webp', '.webp')  # if your system doesn't know it
mimetypes.guess_type('file.webp')[0]  # 'image/webp'

mime.AddExtensionType(".webp", "image/webp")
w.Header().Set("Content-Type", "image/webp")

Accept .webp uploads

<input type="file" accept=".webp,image/webp">

The accept attribute only filters the file picker; users can still choose another file. Listing the extension as well as the type matters, because operating systems don’t always report the type you expect.

Related types

• .avif (image/avif): AVIF image
• .jpg (image/jpeg): JPEG image
• .png (image/png): PNG image
• .gif (image/gif): GIF image

More images

.heic , .ico , .bmp , .tiff . Look up any extension or type with the MIME type lookup.

Sources

• IANA registration: image/webp
• MDN: Common media types

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Frequently asked questions