The Browser Company announced on Thursday that it will sunset its design-focused Arc browser on December 22, 2026, and steer users toward Dia, its AI-first browser, citing rising security costs in the AI era.

"Keeping a browser secure takes constant, dedicated work that is only increasing in the age of AI," the company wrote.

"Dia was built from the ground up to meet today's security standards, so that's where our engineering and security teams will focus moving forward."

The wind-down will occur in three stages. Effective immediately, new Arc accounts cannot be created. On November 23, Arc Search on iOS and Android will lose AI features such as "Browse for Me," and users will no longer be able to sign in or sync tabs, though the app will remain a basic local browser.

On December 22, Arc will cease functioning on Mac and Windows, accounts will be deactivated, and personal data will be erased within 30 days. Arc Search will also be pulled from the Google Play Store.

While The Browser Company says Dia now exceeds Arc in speed, stability and security benchmarks, many social-media users expressed disappointment and called for Arc to be open-sourced.

CEO Josh Miller noted that Arc runs on the Arc Development Kit (ADK), a proprietary internal SDK that also powers Dia, making open-sourcing Arc tantamount to giving away Dia's core IP.

"While we'd love to open-source Arc someday, we can't do that meaningfully without also open-sourcing ADK," Miller previously said. "And ADK is still core to our company's value."

For those transitioning, Dia will retain equivalents of key Arc features. Users can still swipe between work and personal environments via Dia's "Profiles" (formerly Arc's Spaces). Arc's vertical tabs will be offered as an optional sidebar, and Folders are now called "Pinned Tab Groups."

Passwords, bookmarks, extensions and history will move to Dia automatically, and Arc features will stay free within Dia, with AI optional.

The shutdown closes a chapter that began in 2025 when the startup halted active feature development on Arc. The Browser Company, acquired by Atlassian for $610 million in 2025, had earlier admitted that while early adopters loved the novel interface, the "novelty tax" and complexity limited broader uptake. Arc retained a devoted enthusiast base but never achieved the mass-market Chrome alternative the makers envisioned.