Interop 2026 Launches Ambitious Push for Cross-Browser Web Standards

On February 12, 2026, Mozilla Hacks announced the launch of Interop 2026, the latest phase in a landmark industry collaboration aimed at eliminating web compatibility issues across major browsers. Spearheaded by Apple, Google, Microsoft, Mozilla, and Igalia, the initiative builds on the unprecedented success of its predecessors—Compat 2021, Interop 2022 through 2025—to ensure that critical web platform features achieve near-universal implementation and interoperability by year’s end.

According to Mozilla Hacks, the program has evolved from a modest experiment into the most effective mechanism for aligning browser vendors on web standards. Dashboard metrics from Web Platform Tests (wpt.fyi) reveal a dramatic convergence in compatibility scores: by December 2025, all major browsers—Chrome, Edge, Firefox, and Safari—achieved scores above 95%, up from single-digit gaps as recently as 2021. This trend underscores the program’s transformative impact on the web ecosystem, reducing the need for browser-specific workarounds and empowering developers to build once, deploy everywhere.

Interop 2026 introduces two flagship features poised to redefine web experiences. The first is Cross-Document View Transitions, an evolution of the 2025 success with same-document transitions. This feature enables smooth, animated page transitions without JavaScript—transforming traditional multi-page applications (MPAs) into fluid, single-page application (SPA)-like experiences. For developers, this means enhanced user engagement and reduced reliance on client-side routing frameworks, while preserving SEO and accessibility benefits inherent to server-rendered content.

The second major focus is JavaScript Promise Integration for WebAssembly. Currently, WebAssembly modules must either block execution or employ complex callback patterns when awaiting asynchronous JavaScript operations. The new specification allows Wasm code to asynchronously suspend and resume execution upon promise resolution, mimicking native synchronous behavior. This breakthrough simplifies the compilation of languages like C and C++ into WebAssembly, opening the door for high-performance desktop applications—such as CAD tools, video editors, and game engines—to run natively in browsers with minimal code restructuring.

Industry analysts note that these features represent more than technical improvements—they signal a cultural shift in browser development. Historically, competition among vendors led to fragmented implementations and proprietary extensions. Interop 2026 demonstrates a rare consensus: that the web’s long-term health depends on collaboration over competition. Igalia, the non-profit standards contributor, has played a pivotal role in bridging implementation gaps, particularly for Safari and Firefox, which historically lagged in feature adoption.

For web developers, the implications are profound. With cross-browser parity approaching 100% for core features, the need for polyfills, feature detection scripts, and vendor prefixes continues to decline. This reduces bundle sizes, improves performance, and accelerates development cycles. The Interop 2026 dashboard, accessible via wpt.fyi/interop-2026, provides real-time tracking of implementation progress, enabling developers to anticipate feature availability and plan accordingly.

As Jake Archibald, lead engineer at Google and a key voice in the Interop initiative, noted in the Mozilla Hacks announcement, “The web is no longer a battleground of incompatible implementations—it’s a shared foundation we’re all committed to strengthening.” With Interop 2026, that vision is no longer aspirational—it’s operational.