Apple opens Interop 2027 proposals to align Safari, Chrome, and Firefox

Standardizing web technologies across Safari, Chrome, and Firefox reduces the engineering overhead required to maintain consistent video playback and UI performance across different browser engines. For the streaming ecosystem, this initiative ensures that advanced features like WebRTC and WebTransport function reliably regardless of the user's device or browser choice, preventing platform-specific fragmentation. As Apple and its partners move toward Interop 2027, the focus on mature, testable standards will likely accelerate the deprecation of proprietary workarounds for media delivery. Watch for the final list of 2027 focus areas to be announced following the review of developer submissions this fall.

The Interop initiative has become a central mechanism for aligning browser engine development across competing vendors. In 2025, Interop 2025 expanded its focus areas to 27 categories, up from 20 in 2024, with contributions from Apple, Google, Microsoft, Mozilla, and Igalia covering layout, accessibility, and media capabilities. Igalia, a Spanish engineering consultancy, has played an outsized role in the effort, contributing patches to both WebKit and Blink engines. Igalia was recognized in the Interop 2024 wrap-up for its work on CSS Grid and WebGPU implementations, demonstrating that smaller firms can influence the direction of major browser engines through the shared test suite framework. The initiative's reliance on Web Platform Tests as the single source of truth for pass/fail criteria means that streaming-relevant APIs like Media Source Extensions and Encrypted Media Extensions are directly subject to the same compatibility scoring.

On the regulatory front, Apple's participation in Interop carries additional weight following enforcement pressure from the European Union. The EU's Digital Markets Act required Apple to allow alternative browser engines on iOS starting in early 2024, a mandate that directly challenged WebKit's exclusive status on iPhone. Apple initially responded with a compliance framework that drew criticism from developers, and in May 2025 the European Commission opened formal proceedings against Apple over whether its browser choice screen and engine access terms met DMA obligations. Apple and Meta reach DMA compliance agreements that improve Safari's standards compliance could serve as a partial defense against further regulatory scrutiny by demonstrating that Apple is not using WebKit divergence as a competitive moat.

From a technical standpoint, the Interop scoring methodology provides measurable benchmarks that streaming engineers can track. The 2024 Interop results showed that all four major engines reached above 90% pass rates on core CSS and DOM tests, but media-related focus areas like WebRTC and WebCodecs lagged at approximately 75-80%, highlighting where streaming applications still face cross-browser inconsistencies. Apple Safari native HLS pipeline restricts interactive HEVC video performance, which is particularly relevant for streaming platforms building custom players. Mozilla shipped WebCodecs support in Firefox 130 in September 2024, closing a gap that had previously forced developers to fall back to Media Source Extensions for frame-level control. The inclusion of such APIs in Interop 2027 focus areas would give streaming teams a concrete timeline for when they can rely on uniform behavior across Safari, Chrome, and Firefox without engine-specific polyfills.