The Browser Company, led by founder Josh Miller, is integrating select features from its predecessor browser Arc into the new AI web browser Dia, following Arc’s discontinuation and Dia’s $610 million acquisition by Atlassian, to enhance user experience with AI capabilities.
Arc debuted in mid-2023 as an attempt to update web browsing for contemporary internet usage patterns. It introduced separate workspaces to distinguish between professional and personal activities, allowing users to maintain isolated environments without overlap. Pinned tabs enabled quick access to frequently visited sites, keeping them readily available across sessions. The Command Bar functioned similarly to Apple’s Spotlight search, providing a centralized tool for launching applications, searching content, and executing commands efficiently. The sidebar consolidated essential elements, including the search bar for quick queries, a list of open tabs for easy navigation, user bookmarks for organized favorites, and audio controls for managing media playback directly within the interface.
Miller later recognized that Arc’s ambitious design created barriers to widespread use. In a blog post published earlier this year, he stated, “Arc was simply too different, with too many new things to learn, for too little reward… On top of that, Arc lacked cohesion in both its core features and core values. It was experimental — that was part of its charm — but also its complexity.” This assessment highlighted how the browser’s innovative elements, while appealing to some, overwhelmed average users with unfamiliar mechanics and insufficient immediate benefits.
As a result, The Browser Company chose to discontinue Arc and open-source its code, redirecting resources toward Dia’s development. This shift allowed the team to preserve Arc’s codebase for community use while concentrating on a more refined product. The year-plus experience with Arc yielded valuable data on user preferences, revealing which features enhanced browsing and which added unnecessary friction. These observations inform Dia’s design, ensuring it prioritizes elements that align with user needs.
why is dia just becoming arc https://t.co/S3ZkDd1Gzx
— aether (@AetherAurelia) November 1, 2025
On Sunday, November 3, 2025, Miller shared details via a post on X, emphasizing Dia’s improved foundation. He wrote, “Dia’s architecture is much better for AI, speed, and security.” This upgrade addresses Arc’s limitations by optimizing the underlying structure for artificial intelligence integration, faster performance, and enhanced data protection. Miller continued, “We’re adapting Arc’s greatest hits to be native to Dia,” indicating a deliberate incorporation of proven components from Arc into Dia’s core system. He specifically mentioned, “Sidebar mode for Arc fans,” confirming the addition of this popular interface element in Dia’s latest early release for testers. Concluding the post, Miller summarized, “Dia + Arc = snappier, smarter, simpler by default w/ Pro mode— Josh Miller (@joshm) November 3, 2025.” The Pro mode likely offers advanced options, but the base version focuses on streamlined functionality.
Early adopters have tested Dia extensively, providing real-world validation. One long-time Arc user, now participating in Dia’s Early Bird program, posted on X: “I’m daily-driving @diabrowser as a years-long Arc user and now an Early Bird, and I can say I’m so close to not miss Arc. Dia browser now has: – Focus mode – Vertical tabs – Pinned tabs (grid-view) – Google Meet PIP …and I now wait for only three things before deleting Arc—”. This feedback underscores Dia’s progress in replicating Arc’s appeal while introducing refinements.
Beyond the initial list, Dia has implemented automatic picture-in-picture functionality for Google Meet, which activates when users switch tabs, keeping video calls visible and productive. Custom keyboard shortcuts further personalize the experience, allowing users to assign keys to frequent actions for quicker workflows. These additions draw directly from Arc’s effective tools, adapted to Dia’s more efficient framework.
Miller indicated ongoing efforts to migrate Arc’s Spaces feature to Dia. In Arc, Spaces created dedicated browsing zones, each with independent pinned tabs for site access, favorites for quick links, customizable themes for visual distinction, separate history logs for tracking activity, and isolated cookies to prevent cross-session data mixing. Transferring this to Dia would maintain compartmentalized browsing without the prior complexities.
Current testing includes pinned tabs in Dia, with the team evaluating their integration for seamless use. Miller sought user input on potential enhancements, such as swipeable profiles for effortless switching between accounts and updates inspired by Arc Search for the forthcoming Dia mobile application scheduled for 2026. These solicitations aim to refine features based on direct community responses.
Dia emphasizes reduced bloat from inception, stripping away extraneous elements to deliver a lean interface. It incorporates AI-native elements, including memory functions to retain user context across sessions and agents for automated tasks, built into the architecture rather than as afterthoughts. This approach ensures AI drives core operations without compromising simplicity.
Despite the acquisition by Atlassian, The Browser Company maintains independent operations, preserving its agility in development. This autonomy enables the addition of more “browser basics,” which Miller uses to describe beloved Arc features now enhancing Dia. Under Atlassian’s ownership, Dia pursues deeper integrations with tools like Jira for project management and Linear for workflow tracking, embedding browser capabilities into professional ecosystems.
