11ai HTML5 media and embeds

Media affects accessibility, bandwidth, permissions, and third-party privacy at once. Resolve the exact file, public contract, target browsers and assistive technologies, and acceptance check before editing.

Version baseline: HTML5, represented by the current WHATWG HTML Living Standard (last updated 20 July 2026), verified 31 July 2026. Use current conforming HTML5 features; treat frozen W3C snapshots and obsolete elements as legacy, and verify browser and assistive-technology support per feature.

Inspect first

rg -n '<img|<picture|<source|<video|<audio|<track|<iframe' TARGET
rg -n 'loading=|fetchpriority=|allow=|sandbox=|autoplay' TARGET

Resolve the media source, intrinsic dimensions, alternative, expected interaction, third-party origin, and permission needs before editing.

Confirm before changing:

• Useful alt text or intentional empty alt.
• Width and height to reserve layout space.
• Captions, transcripts, and controls.
• Iframe sandbox and permission policy.

Operate

npm run build --if-present
npm test --if-present

Use picture and srcset only when source selection is understood, lazy-load below-the-fold media, and grant embeds only the permissions they require.

Never enable autoplay with sound, remove iframe sandboxing, or download and replace licensed media without explicit approval. Require explicit approval for any broader or destructive form of that change, and preview the affected files or public surface first.

Verify and report

npm run lint --if-present
npm test --if-present
npm run build --if-present

Inspect network requests, layout shift, fallback content, keyboard controls, captions, and blocked-permission behavior. Report the target, files changed, public behavior, compatibility or accessibility impact, checks run, and rollback. Hand configuration failures to 11ai-operator-html-5-troubleshooting and cross-system seams to 11ai-operator-html-5-integrations.