What is Manifest V3?
In a blog post, Google said that Chrome will take a gradual and experimental approach to turning off Manifest V2 to ensure a smooth end-user experience during the phase-out process. “We would like to make sure developers have the information they need, with plenty of time to transition to the new manifest version and to roll out changes to their users,” said the company.
What is the timeline for Manifest V3?
Google has made it clear that Starting in January in Chrome 112, Chrome may run experiments to turn off support for Manifest V2 extensions in Canary, Dev, and Beta channels. Further, starting in June in Chrome 115, Chrome may run experiments to turn off support for Manifest V2 extensions in all channels, including stable channel. In June 2023, the Chrome Web Store will no longer allow Manifest V2 items to be published — which means the old extensions will stop working. From January 2024, if developers of extensions haven’t moved to Manifest V3, the older extensions will all be removed from Chrome Web Store.
Why is this a problem for ad blockers?
According to a report by Ars Technica, ad blockers will become useless once this version is rolled out. The report says that a lot of ad blockers end up relying on an API called webRequest, which is present in Chrome. With Manifest V3, developers will have no choice but to use an API called declarativeNetRequest, which as per the report, will “force them to use a blocklist of specific URLs”. Essentially, Google will create a list of blocked URLs and that list is restricted to just 30,000 entries. Ad-blockers to work effectively come with a list of over 300,000 entries. Many privacy groups have been up in arms against Google’s move to Manifest V3.
Electronic Frontier Foundation, a privacy advocacy group, in a blog post dated December 2021, said that “Manifest V3 is another example of the inherent conflict of interest that comes from Google controlling both the dominant web browser and one of the largest internet advertising networks.”
The privacy group believes that the move to Manifest V3 will will restrict the capabilities of web extensions — “especially those that are designed to monitor, modify, and compute alongside the conversation your browser has with the websites you visit.”