Don't "Accept" image/webp

Name: Don't "Accept" image/webp
Rating: 4.2922 (154 reviews)
Author: jscher2000

By: jscher2000

This extension removes image/webp and/or image/avif from the list of formats Firefox tells sites that it accepts. That discourages many servers from replacing JPEG and PNG images with WebP/AVIF. (But some may send them anyway; they aren't blocked.)

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Features & Capabilities

The "Don't "Accept" image/webp" Firefox extension allows users to disable the browser's acceptance of WebP and AVIF image formats by removing these from the Accept request headers sent to websites. This encourages sites to serve traditional JPEG or PNG images instead, improving compatibility or user preference without blocking images outright. Version 0.8 adds the ability to exempt specific sites, with Patreon exempted by default, while version 0.9 resolves conflicts with other extensions such as "Load Reddit Images Directly" to ensure smooth operation. The extension only modifies the Accept header and does not read request or response data, prioritizing privacy. It acts as a valuable workaround for Firefox users who cannot directly change certain network preferences starting from Firefox 68. This tool helps users regain control over image formats served, enhancing browsing experience and compatibility.

User Growth & Download Statistics

Add-on Privacy & Security Developer Tools

By:

Daily users:

Rating:

Version:

0.9 Last updated: 2023-11-08

Version code:

5647222

Creation date:

2020-06-17

Risk:

Permissions:

Size:

16.90KB

Email:

js*****@outlook.com

URLs:

Website

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-07-06

Compare stats and ranking:

Ranking

# 495 ▼ 2

Other rankings

#66 in Photos, Music & Videos

#14 in hd image keyword 13

#17 in image keyword 74

#19 in hd images keyword 23

#20 in web page keyword 54

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Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

jscher2000

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/dont-accept-webp/

Email:

js*****@outlook.com

Website:

https://github.com/jscher2000/dont-accept-webp

Permission Change History

2023-11-08: Version 0.8.2 → 0.9

Add Permissions: management

User Reviews

Users largely report that the add-on often reduces WebP usage and yields JPEG/PNG on many sites, and that it installs easily. However, effectiveness is inconsistent: some pages still serve WebP, and there is no guarantee it will block WebP on all sites. Positive feedback is common when it works, but reliability varies across sites and pages.

Pros

Blocks or reduces WebP delivery on many sites, often resulting in JPEG/PNG being served instead when possible.
Works as intended on a good number of pages, with users frequently noting it does what it says.
Easy to install and simple to use, with positive quick-start feedback.
Helps users who rely on JPEG/PNG workflows or editing tools that dont support WebP.

Cons

Not reliable across all sites; results are inconsistent and WebP is still delivered on many pages.
No hard guarantee of blocking WebP; the extension mainly suppresses the browser Accept header, but sites can ignore it.
Some popular sites (e.g., YouTube, AliExpress) may still serve WebP or override behavior on certain pages.
Several users report it sometimes does nothing or stops working, indicating unreliable performance across scenarios.

Recent reviews

Doesnt' work for static wikia nocookie but you just add "&format=original" in the url of image (do not forget to open image in the next tab).

by Mê*****, 2026-07-05

Alters your header to indicate your browser doesn't understand the webp format. Some web-servers will return a larger jpeg in place of the webp file, but not all servers will respect that/not all images have a native jpeg backup. This is a limitation of the server, not this extension.

by Al*****, 2026-06-06

Doesn't work.

by Jo*****, 2025-12-14

View all user reviews ›

Is Don't "Accept" image/webp Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

Don't "Accept" image/webp requires some sensitive permissions that could impact your browser and data security. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

Don't "Accept" image/webp has earned a fairly good reputation and likely can be trusted.

Risk likelihood analysis details

Medium This extension has medium user count. Unpopular extensions may not be stable or safe.
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