The most substantive shift is in how privacy works by default. Mozilla is rewriting its Settings section in plainer language, making data choices easier to locate and act on without digging through technical menus. The new design also surfaces tools like private browsing and what Mozilla describes as a free built-in VPN rather than assuming users will find them on their own (Mozilla). Mozilla's announcement does not specify the VPN's availability or limitations.

Settings will also include direct controls for tuning Enhanced Tracking Protection and, for the first time, a master switch to disable AI features entirely (Mozilla). Mozilla frames accessibility as a core dimension of customization rather than a compliance checkbox, and says the new design system supports a strong default experience while leaving deeper flexibility intact.

Project Nova is also the visual culmination of a deliberate 2025 product push. Tab Groups launched as the most requested feature in Mozilla Connect's history (Mozilla), joined by Profiles for separating work and personal browsing, biometric Screen Lock for private mobile tabs, and PDF editing with signatures and commenting (Mozilla). The redesign gives those additions a coherent frame.

One tension worth naming: several 2025 features carry external dependencies that sit awkwardly alongside the independence messaging. Visual Search runs on Google Lens and requires Google as the default search engine to function (Mozilla). Mozilla's financial survival simultaneously depends on Google search revenue. Neither fact invalidates the privacy argument, but they're worth holding alongside it.

Mozilla's AI approach rests on a specific architectural choice: run models locally so browsing data never leaves the device. Several features already work this way, giving the position substance beyond marketing language.

Tab grouping uses a machine learning model compressed from 1GB to 57MB through distillation and quantization, downloaded once on first use and processed entirely within the browser (Mozilla). Page translation converts content locally with no server round-trip (Mozilla). Automatic alt-text generation for PDF images runs on-device, as does the article summarization behind Link Previews. Users can delete any downloaded model at any time from an on-device management screen (Mozilla).

The runtime got meaningfully faster last year. Mozilla replaced a WebAssembly inference layer with a native C++ backend; early benchmarks showed inference speeds two to ten times faster, with one specific task dropping from 3.5 seconds to 350 milliseconds on the same hardware (Mozilla). The engineers also parallelized a previously single-threaded matrix operation and implemented multi-threaded cache-aware transposition, and added graph caching to eliminate cold-start overhead that reached up to five seconds on larger models (Mozilla). GPU acceleration is not yet part of the shipping system; Mozilla says it requires additional sandboxing work before it can be enabled (Mozilla).

Where cloud-based AI enters Firefox, Mozilla's position is provider choice over lock-in. The sidebar lets users select from multiple AI chatbot providers, contrasting explicitly with browsers that assign a single default assistant (Mozilla).

One sourcing caveat applies to this entire section: all of it comes from Mozilla's own engineering and product blogs. No independent benchmarks comparing Firefox's local AI performance against Chrome, Edge, or Safari on equivalent hardware exist in the public record. The technical detail is specific and the architecture is credible, but external validation is absent.

Mozilla's headline figure is a 9% improvement in load times for key page content over the past year, tied to the argument that blocking trackers reduces page load work (Mozilla). The directional logic is sound. Mozilla has not published the methodology, device range, or benchmark construction behind the number, so it reads as a trend indicator rather than a competitive claim.

The AI runtime improvements are more technically grounded. The specific engineering changes parallelized matrix operations, multi-threaded transposition, compiled graph caching have traceable implications and are described in enough detail to be evaluated in principle (Mozilla). Tab grouping accuracy is acknowledged as a work in progress; the team notes future gains will depend on adding time-based signals and refining the embedding model (Mozilla).

Already shipped: Tab Groups (Mozilla), Profiles, Address Bar Shortcuts, Link Previews, Unload Tabs, offline page translation, on-device alt-text generation, PDF editing with signatures and commenting, biometric Screen Lock, AI chatbot sidebar with provider choice, and the faster native C++ AI runtime (Mozilla).

Coming with Project Nova: Redesigned Settings with plain-language privacy controls, the AI features off-switch, more visible access to private browsing and the described built-in VPN, and interface changes across desktop primarily and mobile (Mozilla). No specific release date beyond later this year.

Still requiring scrutiny: The 9% load-time figure lacks published methodology. The built-in VPN claim lacks detail on availability and scope. Independent performance comparisons against Chrome or Safari don't yet exist. And the DOJ antitrust case against Google remains unresolved. Mozilla has argued that banning search revenue payments to independent browsers would "threaten the survival of Firefox," with Mozilla's own expert testimony describing the revenue impact of switching default search providers as "precipitous" (Mozilla).

Mozilla has made a coherent product argument for what Firefox can be. The second half of 2026 will show whether that argument converts into users who pick the browser, not just inherit it.