Deprecations and removals in Chrome 88

Chrome 88 beta was released on December 3, 2020 and is expected to become the stable version in the third week of January 2021.

# Don't allow popups during page unload (enterprises)

Since Chrome 80, pages have no longer been able to open a new page during unloading using window.open(). Since then enterprises have been able to use the AllowPopupsDuringPageUnload policy flag to allow popups during page unload. Starting in Chrome 88, this flag is no longer supported.

# Web Components v0 removed

Web Components v0 have been in a reverse origin trial since Chrome 80. This allowed users of the API time to upgrade their sites while ensuring that new adopters of Web Components used version 1. The reverse origin trial ends with Chrome 87, making Chrome 88 the first in which version 0 is no longer supported. The Web Components v1 APIs replace Web Components v0 and are fully supported in Chrome, Safari, Firefox, and Edge. This removal covers the items listed below.

Custom Elements v0 HTML Imports Shadow DOM v0

# FTP support removed

Chrome has removed support for FTP URLs. The legacy FTP implementation in Chrome has no support for encrypted connections (FTPS), nor proxies. Usage of FTP in the browser is sufficiently low that it is no longer viable to invest in improving the existing FTP client. In addition, more capable FTP clients are available on all affected platforms.

Google Chrome 72 and later removed support for fetching document subresources over FTP and rendering of top level FTP resources. Navigating to FTP URLs results in showing a directory listing or a download depending on the type of resource. A bug in Google Chrome 74 and later resulted in dropping support for accessing FTP URLs over HTTP proxies. Proxy support for FTP was removed entirely in Google Chrome 76.

The remaining capabilities of Google Chrome’s FTP implementation were restricted to either displaying a directory listing or downloading a resource over unencrypted connections.

In Chrome 77, FTP support was disabled by default for fifty percent of users but was available with flags.

In Chrome 88 all FTP support is disabled.

# Deprecation policy

To keep the platform healthy, we sometimes remove APIs from the Web Platform which have run their course. There can be many reasons why we would remove an API, such as:

• They are superseded by newer APIs.
• They are updated to reflect changes to specifications to bring alignment and consistency with other browsers.
• They are early experiments that never came to fruition in other browsers and thus can increase the burden of support for web developers.

Some of these changes will have an effect on a very small number of sites. To mitigate issues ahead of time, we try to give developers advanced notice so they can make the required changes to keep their sites running.

Chrome currently has a process for deprecations and removals of API's, essentially:

• Announce on the blink-dev mailing list.
• Set warnings and give time scales in the Chrome DevTools Console when usage is detected on the page.
• Wait, monitor, and then remove the feature as usage drops.

You can find a list of all deprecated features on chromestatus.com using the deprecated filter and removed features by applying the removed filter. We will also try to summarize some of the changes, reasoning, and migration paths in these posts.