SPOF-O-Matic
Malware Detected
This extension has been flagged as potentially malicious.
Extension Delisted
This extension is no longer available in the official store. Delisted on 2025-09-17.
Detects likely third-party single points of failure as you browse and allows you to Simulate 3rd party resources being unavailable.
Updates in 0.8:
- Create a WebPagetest comparison video directly from the SPOF-O-matic results
Updates in 0.7:
- Improved detection for domains with 3-tiers to the TLD (*.co.uk for example)
Updates in 0.6:
- Fixed black-holing of font stylesheets
Updates in 0.5:
- Added support for detecting external css files for fonts
- Fixed URL parsing to detect more cases
Description:
Detects likely third-party single points of failure as you browse and allows you to Simulate 3rd party resources being unavailable so you can see what the impact would be on sites.
To enable content blocking, click the greyed-out black hole icon in the toolbar.
As you browse the icon in the toolbar will display a warning icon if you are on a site that is likely to have problems loading third-party content. If you click on the icon it will display the list of suspect resources as well as how much of the page content they block (resources closer to the top of the page will have more of a user impact).
Note: SPOF-O-Matic will re-request the pages you browse in order to get the original HTML to scan for blocking scripts so you may see duplicate requests for the base page in tools like fiddler or wireshark.
Latest reviews
really nice tool...
Great extension to test and showcase 3rd party dependencies.
great tool from patrick
thx so much for this tool - we love it!
