Appendix G: Modern platform features: support at a glance (October 2026)
Always confirm on MDN (Baseline badge) before shipping. "Polyfill" means a maintained polyfill exists.
| Feature | Chrome/Edge | Firefox | Safari | Chapter |
|---|---|---|---|---|
Iterator helpers, Set methods, Promise.try (ES2025) |
✔ | ✔ | ✔ (recent versions) | §54–§55 |
ES2026: Array.fromAsync, Error.isError, Math.sumPrecise, Uint8Array base64 |
✔ | ✔ | check MDN | §55 |
| Temporal | 144+ | 139+ | Technology Preview; polyfill | §55 |
using / await using |
134+ | 141+ | partial; compile with TypeScript/Babel | §55 |
| WebGPU | 113+ | 141+ (Windows), expanding | 26+ | §57–§58 |
| Built-in AI: Summarizer, Translator, Language Detector | 138+ desktop | ✘ | ✘ | §59 |
| Built-in AI: Prompt API | extensions; origin trial on the web | ✘ | ✘ | §59 |
WebMCP (document.modelContext) |
early preview / origin trial | ✘ | ✘ | §60 |
Sanitizer API (setHTML) |
146+ | 148+ | ✘ (use DOMPurify) | §59, §65 |
| Trusted Types | ✔ | ✔ (recent versions) | ✔ (recent versions) | §65 |
WebAuthn JSON helpers (parseCreationOptionsFromJSON) |
✔ | ✔ | ✔ (recent versions) | §67 |
scheduler.yield() |
129+ | check MDN | ✘ (fall back to setTimeout) |
§83 |
| Long Animation Frames API | 123+ | ✘ | ✘ | §83 |