Arc vs Firefox

Out of the box, Firefox uses a traditional horizontal tab strip which can get crowded quickly. However, Firefox pioneered 'Multi-Account Containers,' allowing users to color-code tabs that isolate cookies (e.g., banking in one container, social media in another). For vertical tabs, Firefox relies on extensions like 'Tree Style Tab' or 'Sidebery,' which are incredibly powerful but require setup. While highly capable with add-ons, its native management is less innovative than Arc's cohesive system.

Being Chromium-based, Arc inherits Google's security architecture, which is solid against malware. The Browser Company has stated they do not sell user data, and Arc includes built-in ad/tracker blocking capabilities. However, because it relies on the Chromium engine, it is subject to the limitations of Manifest V3 (limiting ad-blocker efficacy) and the underlying engine's telemetry quirks. While better than Chrome, it does not have the institutional privacy DNA that Mozilla possesses.

Arc offers a highly polished, modern aesthetic that feels like a native Apple app. Its unique 'Boosts' feature allows users to customize the look of any website (changing fonts, removing elements, recoloring) with a simple UI, effectively democraticizing CSS injection. The browser adapts its color scheme to the website you are viewing. However, the sidebar layout is mandatory; you cannot revert to a top bar, which forces a workflow change.

Firefox is the most customizable browser in existence if you are willing to tinker. Through userChrome.css, users can completely rewrite the browser's UI, hiding bars, moving buttons, or creating multi-row tabs. For average users, the 'Themes' store is vast. Unlike Arc, Firefox allows you to rearrange almost every UI element (Home, Back, Search bar) via a simple drag-and-drop customization menu. It supports both modern and classic workflows.

Firefox uses Gecko, the only major alternative to Blink and WebKit. While compatible with 99% of the web, users may occasionally encounter sites optimized solely for Chrome that render incorrectly in Firefox. However, Gecko is often more text-rendering friendly and handles font smoothing differently. Firefox has its own extension store, which is large but lacks some specific niche extensions found only in the Chrome Web Store.

Firefox has taken a more cautious approach to AI. While it has introduced sidebar integration for chatbots (allowing you to pin ChatGPT or Gemini to the side), it lacks the deep, browser-level AI utility that Arc offers. Firefox focuses on 'Local AI' experiments to ensure privacy, meaning features are less flashy and cloud-dependent. For users wanting AI to actively manage their browser workflow, Firefox lags behind.

Arc is known to be resource-intensive. Because it renders the web via Chromium and maintains a rich, animation-heavy UI with sidebar previews and Spaces, it can consume significant RAM and battery, especially on laptops. While 'Memory Saver' modes exist, the browser prioritizes smoothness and features over raw efficiency. On older Macs or machines with 8GB of RAM, Arc can feel heavier than its competitors.

Arc has a companion app for iOS and Android (Arc Search) which includes 'Browse for Me' AI summarization. Syncing works well for Spaces and Pinned tabs between Mac and Windows. However, the mobile experience is fundamentally different from the desktop experience, it's more of a companion than a full browser port. The ecosystem is growing but still feels like a 'desktop-first' product.