- Aug 17, 2014
- 11,777
Third-party Chromium web browsers will lose Sync functionality and other functionality as Google will limit access to "private Chrome APIs" starting on March 15, 2021.
Google announced the plan to limit access to APIs on January 15, 2021 on the official Chromium blog. According to the provided information, certain, unnamed, third-party Chromium-based browsers use features that were not intended for use outside of Google Chrome.
Google mentions Sync and Click to Call specifically in the blog post, but those two appear to be not the only ones. There is no full list of APIs that Google considers for internal use only. A developer page on the Chromium web page lists more than 20 different APIs that are not available by default when creating a Chromium-based browser.
Besides Sync, APIs listed on the page include the Translate element, Safe Browsing, or spelling.
All of the listed APIs are not intended for use in distributions, according to the page.
"Many of the Google APIs used by Chromium code are specific to Google Chrome and not intended for use in derived products."
Google discovered the use of these APIs in a recent audit. The company notes that it discovered that some third-party Chromium-based browsers integrated Google features into their browsers, so that "a small fraction of users could sign into their Google Account and store their personal Chrome sync data, such as bookmarks, not just with Google Chrome, but also with some third-party Chromium-based browsers". Google will limit access to private Chrome APIs on March 15, 2021.
The company does not mention the names of the browser's that it discovered during the audit. It seems unlikely that major Chromium-based browsers use this. Browsers like Microsoft Edge or Vivaldi use their own sync infrastructure and functionality.
Google's announcement is vague as it lacks vital information. A likely explanation of what is going on is the following: some browser makers found a way to use certain APIs, the ones mentioned on the developer page linked above, that were not intended by Google for use in distributed third-party browsers; this allowed the makers of the browsers to use Google infrastructure, e.g. storage space and servers, to provide the functionality. Major Chromium-based browsers are likely not affected by the change.

Sync and other features may stop working in some Chromium browsers in March 2021 - gHacks Tech News
Some third-party Chromium web browsers will lose Sync functionality and other functionality in March 2021 as Google will start to limit access to "private Chrome APIs" starting on March 15, 2021.
