The Browser Company will switch off Arc on 22 December, citing security. In 2025, it said only 5.52% of daily users regularly used more than one Space.
Arc, the browser from The Browser Company, stops working on Mac and Windows on 22 December. Sign ups for new Arc accounts closed on 22 October.
A May 2025 letter from the company said few daily users regularly used some of Arc's features. Seventeen months ago it told Arc members "we're not trying to shut Arc down". It also said it was not actively developing the core product experience as it used to.
The company now cites security as the reason for closing Arc. The open question is whether Dia, the newer browser, keeps the power users who built their days around Arc. Atlassian agreed to buy the company behind both in September 2025.
The reason on arc.net is security. The company says keeping a browser secure "takes constant, dedicated work that is only increasing in the age of AI". It says Dia "was built from the ground up to meet today's security standards".
The company's engineering and security teams will now focus on Dia. It also claims Dia now surpasses Arc on stability, speed and security benchmarks, without giving figures.
What the 2025 usage figures showed
The company's letter to Arc members, dated 27 May 2025, explains the business decision. It says Arc's day one retention was strong.
Arc's metrics, though, looked more like a specialised professional tool, such as a video editor, than a mass market consumer product. The letter adds that the company would have stopped work on Arc a year earlier. It says it had already seen the growth and retention data.
Only 5.52% of Arc's daily active users regularly used more than one Space. Live Folders reached 4.17%, and Calendar Preview on Hover reached 0.4%.
The Browser Company reported that Arc's signature features were used by a small share of daily users, while Dia's chat with tabs and personalisation were used by about 40 and 37 percent.
View data
| Feature | Share of daily active users, percent |
|---|---|
| Arc: more than one Space regularly | 5.52 |
| Arc: Live Folders | 4.17 |
| Arc: Calendar Preview on Hover | 0.4 |
| Dia: chat with tabs | 40 |
| Dia: personalisation | 37 |
The same letter gives usage figures for Dia. Its chat with tabs and personalisation features were used by 40% and 37% of daily users.
The company published these numbers to explain why it was backing Dia. They compare different features in different products, so they are not a retention rate. The letter also says Dia is "not really a reaction to Arc and its shortcomings".
Why Arc stayed closed source
The letter also shows what keeping Arc alive involved. It says most people had not noticed that the team stopped building new features, which it took to mean users wanted stability.
The team still made regular Chromium upgrades and fixed security vulnerabilities for Arc. For Dia it grew its security engineering team from one to five.
Arc and Dia also share a foundation, the company's internal toolkit for building browsers, which it calls ADK. The letter says the team had considered both selling and open sourcing Arc, and called either one complicated. Open sourcing Arc would mean open sourcing ADK, which it called core to the company's value.
Atlassian's plans for Dia
Atlassian has its own stated aim for Dia. On 4 September 2025 Atlassian said it had agreed to acquire The Browser Company. It called it "the team behind the incredible Dia and Arc browsers".
Its post argues that today's browsers were built for browsing, not for work. The post sets out the goal of making Dia "the knowledge worker's browser". Security, compliance and admin controls, it said, would be built into every aspect of Dia.
Atlassian estimates the market in its announcement. It says 85% of enterprise workflows happen inside web browsers, and fewer than 10% of organisations have adopted a secure browser. It links Gartner material for both figures.
The post pitches Dia as a browser knowledge workers can bring to the office. Atlassian described its admin controls in September 2025 as an intention, not a shipped product.
Its fourth quarter results show fiscal 2026 revenue of $6.6bn, up 26%, for the year to 30 June 2026. Free cash flow was $1.3bn. The results give no Dia figure.
What users can move and when
The company describes a straightforward move to Dia. Passwords, bookmarks, extensions and history import into Dia. Arc Spaces become Dia Profiles, Dia is free to download, and the AI features are optional.
The company says the browser features people use in Arc are free in Dia. Arc's FAQ says Dia keeps vertical tabs in the Sidebar, Pinned Tabs and Split View. It adds that Dia comes from the team that built Arc, including the whole security team.
The shutdown starts with phone features. On 23 November, Browse for Me and other AI features switch off on iOS and Android. Arc Search then runs as a lite browser with no sign in or sync.
The desktop deadline follows in December. On 22 December the Mac and Windows apps stop, accounts are deactivated and personal data is deleted within 30 days. From 22 October, that gives 61 days of notice.
Until 22 December, arc.net says Arc keeps working and gets basic updates, and existing accounts are unaffected by the sign up change. The latest Arc version adds an option to export all of your data.
Arc Search for Android is also removed from Google Play and from installed devices on 22 December. After that date the company can no longer retrieve Arc user data for data requests.
Moving to Dia needs no export. Anyone heading to another browser can save tabs as links with Export Data, but must do so before 22 December.
On 5 November, Atlassian reports its first quarter of fiscal 2027 at 5pm Eastern, according to its investor events page. The shareholder letter and call are the next place it could give a Dia user number or enterprise customer count.
Until then, the Dia figures in this report are still the company's 2025 feature-usage numbers. Arc users must choose a replacement by 22 December.