Launching Interop 2026 (https://hacks.mozilla.org/2026/02/launching-interop-2026/)

Jake Archibald reports on Interop 2026, the initiative between Apple, Google, Igalia, Microsoft, and Mozilla to collaborate on ensuring a targeted set of web platform features reach cross-browser parity over the course of the year.

I hadn’t realized how influential and successful the Interop series has been. It started back in 2021 as Compat 2021 (https://web.dev/blog/compat2021) before being rebranded to Interop in 2022 (https://blogs.windows.com/msedgedev/2022/03/03/microsoft-edge-and-interop-2022/).

The dashboards for each year can be seen here, and they demonstrate how wildly effective the program has been: 2021 (https://wpt.fyi/interop-2021), 2022 (https://wpt.fyi/interop-2022), 2023 (https://wpt.fyi/interop-2023), 2024 (https://wpt.fyi/interop-2024), 2025 (https://wpt.fyi/interop-2025), 2026 (https://wpt.fyi/interop-2026).

Here’s the progress chart for 2025, which shows every browser vendor racing towards a 95%+ score by the end of the year:

The feature I’m most excited about in 2026 is Cross-document View Transitions (https://developer.mozilla.org/docs/Web/API/View_Transition_API/Using#basic_mpa_view_transition), building on the successful 2025 target of Same-Document View Transitions (https://developer.mozilla.org/docs/Web/API/View_Transition_API/Using). This will provide fancy SPA-style transitions between pages on websites with no JavaScript at all.

As a keen WebAssembly tinkerer I’m also intrigued by this one:

JavaScript Promise Integration for Wasm (https://github.com/WebAssembly/js-promise-integration/blob/main/proposals/js-promise-integration/Overview.md) allows WebAssembly to asynchronously ‘suspend’, waiting on the result of an external promise. This simplifies the compilation of languages like C/C++ which expect APIs to run synchronously.

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