What's new in Chrome extensions and the Chrome Web Store in 2025?

[00:00] Hello and welcome back to Developer Mode. We're closing out the festive season with one last episode. [00:07] For this one, I thought it would be interesting to take a look back at everything that has changed in the Chrome extensions platform, [00:12] and the Chrome Web Store in 2025. And as you can see, we really went all out with the lighting. [00:19] If you're ready to jump straight to the month by month breakdown, you can use the chapters below. [00:23] Otherwise, I have some thoughts on the year as a whole, and then we'll get straight into it. [00:33] 2025 is almost over. A lot has happened. The transition to Manifest v3 is complete, and we've launched new platform APIs in Chrome and a lot of really exciting capabilities in the Chrome Web Store. [00:45] Of course, AI has been an overarching theme for the year. Overwhelmingly, what I've seen is extensions being used as a platform to experiment. [00:54] whether that is with new agenting capabilities where an extension drives the browser, or as a way to add smaller pieces of functionality to existing features like tab groups. [01:03] I think that experimentation with extensions will only continue as technologies like MCP and WebMCP mature. But I'll leave the speculation about where the future is going for another video. [01:14] And of course, lots has been happening in the community too. [01:17] Libraries like WXT, which make building extensions easier, have continued to gain adoption. And there have been some great talks on extensions, which I've seen at events throughout the year. [01:27] So we'll start in January. We launched a new DevTools feature, which allows you to see data stored in the Chrome.Storage extension API.

[01:36] At the time, a feature request for this was the fourth most starred issue for DevTools, so I was really excited when we released this. [01:43] I recorded a fun "What's New in DevTools" video about this feature with the team if you want more details. [01:48] Moving on to February, we added support for creating multiple worlds in the User Scripts API. [01:55] That was a bit of a niche change, but work on that API continued into March when we launched the userscripts.execute API. [02:02] That one had come up a lot as a request from developers, and allows you to immediately execute arbitrary code provided by the user [02:09] as long as the necessary conditions are met. [02:11] March was also the month when we launched the ability to cancel a pending submission in the Chrome Web Store. [02:17] That's really useful if you have changes you want to make and want to update your submission immediately rather than waiting to hear back on your current one. [02:25] This has honestly been a long time coming, so I'm glad we can finally say it's here. [02:30] In April, we landed some new changes in the Puppeteer testing library to make it easier to load extensions. [02:36] This was all built on top of WebDriver ByDye, a new standard that browsers have been working together on, which provides a much greater range of testing capabilities when compared to its predecessor. [02:46] May was Google I/O month. There are two great videos from that time, so I'll leave you to watch those on your own. [02:52] Suffice it to say that David, Hafsa and Sebastian were the first to talk about a lot of what I'm covering today. [02:59] in June. [03:00] we announced some changes to how users grant extensions access to the User Scripts API. [03:05] Previously, you had to enable developer mode on the Chrome extensions page, but that was a global toggle and it was a bit unclear to users.

[03:12] There's now a separate toggle for individual extensions, which is something largely based on feedback that you shared. [03:18] June was also the month when many of the built-in AI APIs in Chrome made it to stable. [03:23] With Chrome 138, you can use the prompt API in Chrome extensions and the summarizer, translator, and language detector APIs anywhere on the web, including extensions. [03:34] All without a flag or origin trail. [03:36] Our built-in AI documentation has everything you need to get started. [03:41] In July, we largely completed the transition to Manifest V3, [03:45] disabling Manifest V2 on all channels for all users. [03:49] The final piece was turning it off for users of enterprise policy [03:52] which happened later in the year. [03:54] Now, I know this has been a lot of work for the whole community, so thank you for working with us. [03:59] August was the end of a few months of travel for much of the team, with IO Connect in Berlin in June, India in July, and China in August. As part of this, we held a meetup with the Google Developer Group in Shanghai, and it was great to see how big of a community we have in China. [04:14] Thanks to everyone for coming along. [04:17] In September, we started shipping various additions to the sidepanel API. [04:21] This was part of Google Summer of Code, a program where students can contribute directly to Chromium. [04:26] That included sidepanel.getLayout to determine if the panel is on the left or right of the screen, and on opened and on closed events. [04:34] We also ship some improvements to the error section on the Chrome extensions page. [04:39] October saw the launch of the new Chrome Web Store API. This has new capabilities like authentication with service accounts and the ability to update partial rollout percentages.

[04:49] One thing that I'm really excited about here is more detailed API reference documentation and libraries to interact with the API. [04:56] Using those is much simpler than writing API calls by hand. [05:00] We continued the Chrome Web Store launches in November, beginning the rollout of new publisher pages that show all items from a given publisher. [05:08] And we also announced support for the browser namespace as an alternative to accessing extension APIs with the window.chrome global. [05:16] We had tried to roll this out earlier in the year, but found some incompatibilities with Mozilla's Web Extension Polyfill library. So we made a number of improvements to our messaging APIs, and we're giving that a second try. [05:28] That change is moving through Chrome's release process, and if all goes well, it should be in stable by January. [05:34] Which brings us to now! It's been a busy year of launches, not to mention all of the various events we've been attending and other things we've been doing throughout 2025. [05:44] Thank you for being part of the community and watching our videos, and for making libraries, replying to questions from other developers, and generally making this a great space to be a part of. [05:54] Bob, see you next year! [05:55] Happy holidays.