Ever since The Browser Company decided to shift gears and focus primarily on Dia, long-time Arc users have continuously complained that several important features were missing from the browser. However, that is changing lately.
A few days ago, v1.42.0 (84218) came out, which included subtle refinements. As usual, the official Release Notes don’t mention the key changes directly. I was able to find a more consolidated changelog from u/JaceThings on Reddit — this account consistently tracks all Dia updates. You can view the relevant images below.

However, the biggest addition to Dia with this update is not the new “Thinking” UI or the Chromium engine update. It’s the quiet addition of the Spaces (workspaces) feature.
Once I updated the browser, I noticed that Spaces were present immediately in the sidebar. It’s strange that The Browser Company decided to simply not mention the one change that people have been anticipating for months.

Just a few days ago, we covered a story where Spaces were showing up for some users in early bird testing. However, I’m not using a testing version, and the feature is present even on the stable release, suggesting that it’s public now.
While Dia has received fairly consistent updates since its launch, the lack of workspaces caused many people to turn away from daily driving the browser, including me.
It’s worth noting that v1.42.0 is no longer the latest version of Dia (it came out a few days ago). In fact, it’s v1.42.1 (84365) that’s the current version, at the time of writing. There’s a slight possibility that I received Spaces in this update, but some comments on Reddit suggest that it was added in v1.42.0.

If you don’t see Spaces even after updating, it might be a staged rollout (not everyone will receive it at once). The company hasn’t issued an official statement about this, so it’s difficult to conclude.
Despite browsing through the Release Notes and Reddit, I was unable to find a changelog for this, so I’m assuming it’s a minor update that doesn’t bring anything user-facing.
In other Dia news, the long-awaited Windows version of the browser has recently been teased, with a vague release time of “fall of 2026.” More on that here.