Arcmark: Bringing the Arc Sidebar Experience to Every Browser

2026-02-21 | Product Hunt | Official Site | GitHub

Interface Breakdown: On the left is the Arcmark sidebar, a cyan window attached to the browser showing workspaces (Katalog), folders (Applications, Billing), and quick-launch icons. On the right is a standard Chrome window. The design is minimalist, feeling like Arc's sidebar extracted into a standalone app.

30-Second Quick Judgment

What is it: A native macOS bookmark manager that "sticks" to any browser window like a sidebar, bringing Arc's most popular bookmark management experience to Chrome, Safari, Brave, and more.

Is it worth watching: If you're an ex-Arc user, or if you've always envied Arc's sidebar but didn't want to switch browsers—it's worth a 5-minute trial. It's free, open-source, and costs nothing to try. However, if you already have a mature bookmarking setup (Raindrop.io, Anybox, etc.), this might feel too lightweight.

Interesting Backstory: After Arc Browser was acquired by Atlassian for $610M in September 2025, feature development stalled, leading many users to seek alternatives. Arcmark developer Ahmed Sulaiman was one of them—he wanted to leave Arc but couldn't give up the sidebar, so he wrote his own in Swift.

Three Questions That Matter

Is it for me?

Target User Persona:

• Former Arc users migrating to other browsers due to Arc's stagnation.
• macOS users who need to manage a large volume of bookmarks/links daily.
• Developers or knowledge workers who frequently switch between multiple sites.

Are you the target? If you meet these criteria: (1) Use a Mac, (2) Have over 50 bookmarks, (3) Feel native browser bookmark management is too weak—then yes.

When would you use it?:

• When migrating from Arc to Chrome/Safari and wanting to keep the sidebar organization—Use it.
• When conducting project research and wanting to categorize links by workspace—Perfect.
• If you need cross-browser sync or mobile access—Not for you; check out Raindrop.io.

Is it useful?

ROI Judgment: If you open more than 20 different websites a day, it's worth a shot. Zero cost—the worst-case scenario is spending 5 minutes to find it's not for you and deleting it.

Is it delightful?

The "Aha!" Moments:

• Sidebar auto-follow: The sidebar moves with the browser window when switching Spaces; no need to reopen it.
• Workspaces + Custom Colors: Distinguish different projects by color at a glance.
• Arc Import: Import pinned tabs directly from Arc for a painless migration.

Real User Feedback:

"You get workspace-based links/bookmarks organization with nested folders, drag-and-drop reordering, and custom workspace colors. For the most part, I tried replicating Arc's sidebar UX as close as possible." -- Developer Ahmed Sulaiman (Hacker News)

The editor of Tao of Mac featured Arcmark within days of its release, calling it "a native macOS bookmark manager that can be attached to any browser window as a sidebar." -- Tao of Mac

On the Mac Power Users forum, Arc users have been discussing the lack of good bookmark management; Arcmark hits that pain point perfectly. -- MPU Talk

For Independent Developers

Tech Stack

• Language/Framework: Swift + AppKit (Pure native macOS, not Electron)
• Storage: A single JSON file (~/Library/Application Support/Arcmark/data.json)
• Core API: macOS Accessibility API (Used to attach the window to the browser)
• Build Tools: Shell scripts (./scripts/run.sh, ./scripts/build.sh --dmg)
• License: MIT

Core Implementation

Arcmark's technical highlight is using the macOS Accessibility API for window attachment. Essentially, it listens for the active browser window's position and "pins" its own window next to it, following it through movements and Space switches. This clever implementation requires Accessibility permissions; without them, it functions only as a standard standalone window.

The data layer is extremely simple—just a JSON file. No database, no Core Data, just direct JSON I/O. For the low-frequency write scenario of bookmarking, this is perfectly adequate, and users can easily back up or manually edit the file.

Open Source Status

• Fully Open Source: github.com/Geek-1001/arcmark
• MIT License: Free to fork, modify, and use commercially.
• Clean code structure with CLAUDE.md and docs/ explaining the architecture.
• Build Difficulty: Medium. Estimated 2-3 weeks for a single dev to build a base version. The challenge lies in the window-following logic via the Accessibility API.

Business Model

None. This is a pure personal side project to solve the developer's own problem. No fees, no ads, no data collection.

Giant Risk

Yes, but low. Browser vendors (Chrome, Safari) could improve their bookmarking at any time, but they haven't done much in 10 years. The real risk comes from competitors like SupaSideBar, which is more feature-rich and commercialized. However, Arcmark's "free + open-source" positioning gives it a unique niche.

For Product Managers

Pain Point Analysis

• Core Pain Point: Arc Browser's 2025 stagnation left users needing to migrate but missing the sidebar experience.
• Pain Intensity: Mid-frequency essential. It's a major pain point for ex-Arc users and a "nice-to-have" for others.
• Market Context: After Arc's $610M acquisition by Atlassian and the shift toward the Dia browser, the community complained about feature stagnation. Zen Browser has already gained 38,300 GitHub Stars as an alternative.

User Personas

Feature Breakdown

Competitor Comparison

Key Takeaways

1. "Unbundling" Strategy: Arc is a full browser; Arcmark extracts only the most popular sidebar feature into a standalone tool. This "unbundling platform features" approach is worth noting.
2. Perfect Timing: Launching a sidebar alternative exactly when Arc users are looking for an exit strategy is brilliant.
3. Local-First + Simple Data: Using JSON instead of a database allows users to own their data—backing up, migrating, or editing it manually.

For Tech Bloggers

Founder Story

• Ahmed Sulaiman (GitHub: Geek-1001), London.
• Current Product Lead at Pitch (collaborative presentation tool).
• Previously worked at Abstract (design version control) and Flawless App (acquired UI tool).
• Techstars alum and co-founder/CEO of Fragment.
• Also building CrossPatch (crosspatch.io), a team progress tracker.
• Motivation: "I wanted to leave Arc but couldn't give up the sidebar, so I wrote my own."

Discussion Angles

• The Death of Arc and the War of Alternatives: Following the $610M acquisition, the community split. Some went to Zen Browser, some are waiting for Dia, and others are looking for sidebar replacements like Arcmark and SupaSideBar.
• Open Source vs. Commercialization: Arcmark chose free/open-source; SupaSideBar chose a subscription. Which is more sustainable?
• The Accessibility API Controversy: Requiring system-level permissions for window attachment may worry security-conscious users.

Hype Data

• PH: Only 2 votes, very low heat currently.
• Hacker News: Show HN post from about 6 days ago.
• Tao of Mac: Featured and covered.
• Overall Judgment: Very early stage, hasn't gone viral yet. However, the "Arc alternative" niche is hot (Zen Browser 38K+ Stars).

Content Suggestions

• The Hook: "Arc is dead, but its sidebar was just resurrected by open source"—tell the Arcmark story within the context of the acquisition.
• Trend Jacking: Use the recurring "Arc alternative" discussions to highlight this tool.

For Early Adopters

Pricing Analysis

No paid version, no "Pro" features. MIT licensed—you can even fork it to make it your own.

Getting Started

• Setup Time: 5 minutes.
• Learning Curve: Low.
• Steps:
  1. Download the DMG from GitHub Releases.
  2. Open and grant Accessibility permissions (for the sidebar attachment feature).
  3. Create workspaces, add bookmarks, and drag to organize.
  4. If you're an Arc user, go to Settings for a one-click Pinned Tabs import.

Pitfalls & Complaints

1. Accessibility Permissions: Mandatory for the core attachment feature, which triggers a system security prompt.
2. macOS Only: Windows, Linux, and iOS users are out of luck.
3. No Cloud Sync: If you switch Macs, you must manually move the JSON file.
4. Very Early Stage: Low PH votes and recently released; expect some bugs.

Security & Privacy

• Data Storage: 100% local, single JSON file, no internet connection.
• Privacy: No data collection, no account registration required.
• One Concern: Accessibility permissions theoretically allow an app to read screen content. However, Arcmark is open-source, so you can audit the code yourself.

Alternatives

For Investors

Market Analysis

• Segment Size: Bookmark management market ~$500M in 2024, projected to reach $1.2B by 2033 (10.5% CAGR).
• Broader Market: Online bookmarking services market ~$2B in 2025, reaching $4.3B by 2035.
• Key Stat: 72% of digital professionals rely on bookmarking tools; remote work has boosted growth by 55%.

Competitive Landscape

Timing Analysis

• Why Now: Arc's acquisition and stagnation in late 2025 created a massive pool of "homeless" power users.
• Tech Maturity: macOS Accessibility API is mature; Swift/AppKit development is efficient for experienced devs.
• Market Readiness: Arc successfully educated users on the value of sidebar management; the demand is real.

Team Background

• Founder: Ahmed Sulaiman, Product Lead @ Pitch, ex-Abstract/Flawless App.
• Team Size: Solo personal project.
• Track Record: Flawless App was acquired; Techstars alum; multiple successful open-source projects.

Funding Status

• Unfunded: Personal open-source project with no current commercial intent.
• Investment Suitability: Low. The founder has explicitly positioned this as a free open-source side project, not a startup venture.

Conclusion

One-liner: Arcmark is a precision tool for the "I miss Arc's sidebar" pain point—free and open-source, but still in its early, basic stages.

Resource Links

2026-02-21 | Trend-Tracker v7.3