Known limitations
We strive to provide the best possible experience for our users, but no software is perfect. This page outlines some of the known limitations of tweak, so that users can be aware of any potential issues they may encounter.
Intercepting service worker requests​
tl;dr tweak DOES NOT intercept service worker requests.
If your aim is to use tweak to intercept and mock requests made from service workers, then tweak won't work for you. Due to tweak's design and platform limitations it's impossible for our extension at this time to support service workers. If this is a critical use case for you, reach out to us via email, your feedback it's very important to use.
Rewriting the body of a document​
tl;dr tweak DOES NOT let you rewrite the contents of documents such as HTML, CSS or JavaScript files.
Mock and modify rules work with XHR and fetch; those are the requests whose body you can edit. Our tool is especially designed and optimized for this particular use case, so if you work with XHR or fetch, picking tweak is a no-brainer.
You can point those files somewhere else, though: a redirect rule swaps a stylesheet, a script, an image or the page navigation itself for another URL (a local build, for instance), and a headers only rule rewrites their headers. Both are applied by the browser rather than by tweak inside the page, which is why they reach requests XHR and fetch never see. What neither can do is edit the bytes that come back.
Headers only and redirect rules are Chromium only​
Headers only and redirect rules are applied by the browser itself, through an API the Firefox build does not have. They are available on Chrome and other Chromium browsers (Edge, Brave, Arc, Opera); on Firefox the rule type dropdown does not offer them. Mock and modify rules work on both.
Disabled sites​
Frequent users that have the tweak extension enabled have reported issues across particular widely used web applications such as Google Calendar or Gmail. In order to avoid any interference with the normal operation of these applications, tweak will not load on these specific domains. Here's the complete list of disabled sites:
- google.com (all subdomains: Gmail, Calendar, Docs, Drive, Meet, Sheets, YouTube, Cloud Console, etc.)
- zoom.us
- teams.microsoft.com
- zendesk.com
- clickup.com
- chat.openai.com / chatgpt.com
- x.com
- facebook.com
- instagram.com
- linkedin.com
- tumblr.com
- stackblitz.com
- costco.com
Tweak also does not load when you open files with the formats csv, json or xml directly in the browser.
Slow popup opening​
tl;dr this is a long-standing Chrome bug, not something tweak can fix on its own.
Some users report that clicking the tweak toolbar icon feels sluggish: the click animation plays for about 0.25s, then there's dead air for roughly 0.75s before the popup actually appears. This is intermittent but recurrent, and it's the delay you feel on the "bad" opens.
This is not specific to tweak. The same behavior has been reproduced against other popular extensions such as Tampermonkey, Feedly Notifier and uBlock Origin (though notably not against Stylish), and it has been tracked upstream in the Chromium issue tracker for years:
Because the delay happens in the browser's own extension popup rendering path, before tweak's code runs, there is no workaround we can ship from our side. We keep tweak's popup startup work as small as possible so that once Chrome hands over control, the UI is ready immediately.
Found other issues?​
If you want to report a problem or bug please submit your request here.
Need something else? Request a feature