Intent to Experiment: HTML-in-canvas

[Philip Rogers]

Contact emails

chri...@chromium.org, sche...@chromium.org, p...@chromium.org, sza...@chromium.org, foo...@chromium.org

Explainer

https://github.com/WICG/html-in-canvas

Specification

https://github.com/whatwg/html/pull/11588

Summary

HTML-in-canvas enables customizing the rendering of html using canvas with three new primitives: an attribute to opt-in canvas elements (layoutsubtree), methods to draw child elements (2d: drawElementImage, webgl: texElementImage2D, webgpu: copyElementImageToTexture), and a paint event which fires to handle updates.

Blink component

Blink>Canvas

Web Feature ID

canvas

Goals for experimentation

API shape

Origin Trial documentation link

https://github.com/WICG/html-in-canvas

Goals for experimentation

None

Risks

Interoperability and Compatibility

This API exposes a small amount of new information which carries an interop risk, such as the pixels of gradients and form controls.

Gecko: Negative (https://github.com/mozilla/standards-positions/issues/1076) Mozilla did not object to advancing the spec to stage 2 (consensus around rough API shape), and we are actively working to address their concerns about fingerprinting and compatibility.

WebKit: No signal (https://github.com/WebKit/standards-positions/issues/630)

Web developers: Positive (https://github.com/whatwg/html/issues/10650#issuecomment-3324124682) We have positive signals from users of the DevTrial: https://github.com/whatwg/html/issues/10650#issuecomment-3324124682

Other signals:

Security

https://github.com/WICG/html-in-canvas?tab=readme-ov-file#privacy-preserving-painting

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

No information provided

Debuggability

Content under canvas can be debugged like regular DOM content via devtools.

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

Yes
https://source.chromium.org/chromium/chromium/src/+/main:third_party/blink/web_tests/wpt_internal/html/canvas/drawElementImage/

DevTrial instructions

https://github.com/WICG/html-in-canvas?tab=readme-ov-file#developer-trial-dev-trial-information

Flag name on about://flags

chrome://flags/#canvas-draw-element

Finch feature name

CanvasDrawElement

Requires code in //chrome?

False

Tracking bug

https://crbug.com/500967896

Measurement

HTMLInCanvas UseCounter

Estimated milestones

Origin trial desktop first	148
Origin trial desktop last	151
DevTrial on desktop	138
Origin trial Android first	148
Origin trial Android last	151
DevTrial on Android	138
Origin trial WebView first	148
Origin trial WebView last	151

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5172548013916160

Links to previous Intent discussions

Intent to Prototype: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/a473b17f-def6-4bb7-85ee-344947c5ecabn%40chromium.org

This intent message was generated by Chrome Platform Status.

[Mike Taylor]

Exciting stuff - 

LGTM to experiment from M148 to M151 inclusive.

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[Mike Taylor]

Let me amend... LGTM once you've requested Privacy, Security, and Debuggability bits in your Chromestatus entry (in the Origin Trial section).

[Philip Rogers]

Correction: Gecko's position should be "No Signal". I've updated this in the Chromestatus link.

On Thursday, April 9, 2026 at 12:50:47 PM UTC-7 Mike Taylor wrote:

Let me amend... LGTM once you've requested Privacy, Security, and Debuggability bits in your Chromestatus entry (in the Origin Trial section).

On 4/9/26 3:48 p.m., Mike Taylor wrote:

Exciting stuff - 

LGTM to experiment from M148 to M151 inclusive.

On 4/9/26 2:49 p.m., Philip Rogers wrote:

Contact emails

chri...@chromium.org, schenney...@chromium.org, pdr@chromium.org, sza...@chromium.org, fooli...@chromium.org

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[Jake Archibald]

Thank you. We've been giving feedback on this API, and building demos to test parts of it. We definitely have concerns around the API, such as there being no way to set the texture size in WebGL, but we don't have an official positive/negative position right now.

When we have a position, we'll assign a label to https://github.com/mozilla/standards-positions/issues/1076. For comparison, see the current version of the translation API which has a negative position.

Jake.