Intent to Deprecate and Remove: "on-demand" value for hover/any-hover media queries.

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Mustaq Ahmed

Mar 7, 2017, 10:43:35 AM3/7/17
to blink-dev

Primary eng (and PM) emails


Remove the support for “hover: on-demand” and “any-hover: on-demand” media queries. The “on-demand” value is satisfied for the pointing devices that, for example, “can't normally hover, but will activate hover on a long press”.

After the proposed change, a pointing device that used to satisfy the “on-demand” value would satisfy the “none” value instead.


The “on-demand” value for hover/any-hover media queries has been removed from the spec about a year ago because it doesn’t seem to have a convincing use case.

Spec change:

Spec discussion:

Compatibility And Interoperability Risk

The risk of breakage is low because of low usage. We manually tested selected existing sites (among the few we found) that contain “hover: on-demand”, and found them working fine with the proposed change. See Usage Information below for details.

The interop risk is also low since mobile Safari doesn’t support “on-demand”, and Firefox doesn’t even support hover/any-hover media queries ( Edge has a bug to remove “on-demand” support (

Alternative implementation suggestion for web developers

After the change, web developers should use “hover: none” and “any-hover: none” instead of “hover: on-demand” and “any-hover: on-demand” respectively.

Usage information

UseCounter data: So far we have data available from M57 beta (and dev as well) which shows that ~0.02% page visits parse the “on-demand” CSS value.

HttpArchive data: In the 2015-01-15 dataset, there are ~35 sites matching r"hover:\s*on-demand" (out of 16.7M entries). We manually checked the top ones among those ~35 sites (more precisely, the ones with ranking <50k) using a Chromium build that doesn’t support “on-demand”, and found all of them working fine:

OWP launch tracking bug

Entry on the feature dashboard

Requesting approval to remove too?


Chris Harrelson

Mar 10, 2017, 12:58:21 PM3/10/17
to Mustaq Ahmed, blink-dev

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Dimitri Glazkov

Mar 11, 2017, 11:00:53 AM3/11/17
to Chris Harrelson, Mustaq Ahmed, blink-dev

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Jochen Eisinger

Mar 16, 2017, 1:32:24 PM3/16/17
to Dimitri Glazkov, Chris Harrelson, Mustaq Ahmed, blink-dev
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