Hello all, This is hopefully our final extension request for this feature. As noted in the template, I am requesting for M153 in order to ensure we have time to do final updates that were discovered as necessary when re-enabling tests that were written during early development. All anticipated large-scale changes have landed.
Best, Michael On Tue, Jul 21, 2026 at 2:43 PM Chromestatus < [email protected]> wrote: > *Contact emails* > [email protected], [email protected] > > *Specification* > > https://webaudio.github.io/web-audio-api/#dom-baseaudiocontext-renderquantumsize > > *Design docs* > *No information provided* > > https://github.com/WebAudio/web-audio-api/blob/main/explainer/user-selectable-render-size.md > > *Summary* > Adds an optional renderSizeHint to AudioContext and OfflineAudioContext. > This allows developers to customize the WebAudio render quantum size by > passing a specific integer, use the default of 128 frames by omitting the > hint or passing "default", or request that the User-Agent select an optimal > size by specifying "hardware". > > *Blink component* > Blink>WebAudio > <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWebAudio%22> > > *Web Feature ID* > web-audio <https://webstatus.dev/features/web-audio> > > *TAG review* > *No information provided* > > *TAG review status* > Issues addressed > > *Origin Trial Name* > WebAudio Configurable Render Quantum > > *Goals for experimentation* > Validate performance improvement gained by matching render quantum size to > software buffer sizes when using a numeric renderSizeHint. Verify actual > audio processing output is unchanged when using a numeric renderSizeHint. > We have a primary partner for this Origin Trial, and we would like to see > if the performance and ergonomics of the API satisfy this partner's need. > This partner is not going to use the "hardware" hint, and we think that it > is still valuable to conduct an Origin Trial to gather feedback on the rest > of the API. > > *Chromium Trial Name* > WebAudioConfigurableRenderQuantum > > *Origin Trial documentation link* > > https://webaudio.github.io/web-audio-api/#dom-audiocontextoptions-rendersizehint > > *WebFeature UseCounter name* > kWebAudioRenderSizeHint > > *Risks* > > > *Interoperability and Compatibility* > Low. The feature is already specified. > > *Gecko*: No signal ( > https://github.com/mozilla/standards-positions/issues/1407) A Firefox > developer wrote the specification change ( > https://github.com/WebAudio/web-audio-api/pull/2469). > > *WebKit*: No signal ( > https://github.com/WebKit/standards-positions/issues/662) > > *Web developers*: Positive ( > https://github.com/WebAudio/web-audio-api/issues/1503) Developers have > requested a way to increase the render quantum size, and are looking > forward to the feature being implemented. > > *Other signals*: > > *Ergonomics* > An identified use case of this feature is to match buffer sizes used by > other Chromium audio APIs, in order to improve performance. > > *Activation* > There is an ongoing privacy discussion about how to mitigate > fingerprinting concerns around the "hardware" hint ( > https://github.com/WebAudio/web-audio-api/issues/2659). The "hardware" > hint as implemented in Chromium currently will always return the default > 128 render quantum size, which exposes no user information. This is allowed > by the spec, which says "It is a hint that might not be honored." > > *Security* > There is concern that a very low render quantum size could allow an > AudioWorklet to create a high-resolution timer, but very high sample rates > are already allowed and have a similar risk so the marginal change in > security is probably low. > > *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? > Low. The change is to ship a new API. > > > *Reason this experiment is being extended* > Unexpected delays in implementation, due in part to issues which were > uncovered by the Origin Trial itself. We would like one more milestone for > the trial. > > *Reason this experiment is being extended* > During the last extension we resolved the fingerprinting concerns and > landed what we thought were our final changes, but re-enabling tests that > were added during early development revealed that some nodes still need to > be manually updated. It's possible that the work could be finished before > M152 branch, but it would be a very tight deadline so we would like one > final extension to M153. > > *Reason this experiment is being extended* > During the previous extension we uncovered additional fingerprinting > concerns that we would like to resolve before shipping. Team member out of > office time means that we will not be able to resolve this before M151, and > we would like the trial extended to coincide with the new shipping date if > possible to continue gathering feedback. > > *Ongoing technical constraints* > None. > > *Debuggability* > It may be worth exposing the render quantum size value in the DevTools > WebAudio pane, similar to sample rate. > > *Will this feature be supported on all six Blink platforms (Windows, Mac, > Linux, ChromeOS, Android, and Android WebView)?* > Yes > All supported platforms have mechanisms to implement this feature. > > *Is this feature fully tested by web-platform-tests > <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* > Yes > > https://wpt.fyi/results/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-rendersizehint.html > https://wpt.fyi/results/webaudio/the-audio-api/the-offlineaudiocontext-interface/offlineaudiocontext-rendersizehint.html > > *Flag name on about://flags* > N/A (launch with --enable-features=WebAudioConfigurableRenderQuantum) > > *Finch feature name* > WebAudioConfigurableRenderQuantum > > *Requires code in //chrome?* > False > > *Tracking bug* > https://crbug.com/40637820 > > *Launch bug* > https://launch.corp.google.com/launch/4416924 > > *Measurement* > UseCounters: WebAudioRenderSizeHint, WebAudioRenderQuantumSize > > *Availability expectation* > We expect that Firefox will implement the feature independently at some > point. > > *Adoption expectation* > We expect that specific partners will use this functionality immediately > upon its launch in Chrome. > > *Adoption plan* > We are communication with partners, and also in communication with Mozilla > via the Audio Working Group. > > *Non-OSS dependencies* > > Does the feature depend on any code or APIs outside the Chromium open > source repository and its open-source dependencies to function? > No. > > *Estimated milestones* > Shipping on desktop 153 > Origin trial desktop first 145 > Origin trial desktop last 151 > Origin trial extension 1 end milestone 151 > Origin trial extension 2 end milestone 153 > Origin trial extension 3 end milestone 152 > DevTrial on desktop 145 > Shipping on Android 153 > Origin trial Android first 145 > Origin trial Android last 151 > Shipping on WebView 153 > Origin trial WebView first 145 > Origin trial WebView last 151 > > *Anticipated spec changes* > > Open questions about a feature may be a source of future web compat or > interop issues. Please list open issues (e.g. links to known github issues > in the project for the feature specification) whose resolution may > introduce web compat/interop risk (e.g., changing to naming or structure of > the API in a non-backward-compatible way). > https://github.com/WebAudio/web-audio-api/issues/2663 > https://github.com/WebAudio/web-audio-api/issues/2664 > > *Link to entry on the Chrome Platform Status* > https://chromestatus.com/feature/5078190552907776?gate=5107396847468544 > > *Links to previous Intent discussions* > Intent to Prototype: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/688d3254.2b0a0220.361edb.0299.GAE%40google.com > Intent to Experiment: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CA%2BuAeqS%3DygCo2wPaf0Cfo%2B%2BdEoHGWx%2Byc4%2BfO84U%2B_5hQqOvYg%40mail.gmail.com > Intent to Extend Experiment 1: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/69dd7ab5.050a0220.c8e20.0171.GAE%40google.com > Intent to Extend Experiment 3: > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6a3319c8.3af95f39.17d45c.005e.GAE%40google.com > > > This intent message was generated by Chrome Platform Status > <https://chromestatus.com>. > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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