This is a second time request for ServiceWorkerAutoPreload. The previous request was closed in #963. Now we have other browser interest, draft spec change, and the proposal was transferred into WICG. So let us ask the TAG review again.

こんにちは TAG-さん!

I'm requesting an early TAG design review of ServiceWorkerAutoPreload.

ServiceWorker fetch handlers are used for various reasons but there are many cases where developers use them with the intention of serving resources faster than the network, however in some cases ServiceWorker could be slower because of its startup. To fulfill their intention, this document proposes the introduction of “ServiceWorkerAutoPreload”, a new loading strategy for ServiceWorker. ServiceWorkerAutoPreload is a mode where the browser issues a network request (i.e. a regular request which may result in a HTTP cache hit or an actual fetch) in parallel with the ServiceWorker bootstrap, and consumes the network request result inside the fetch handler.

• Explainer¹: url

• User research: it is a well-studied phenomenon that faster sites are better for users, but we have not conducted any user studies specifically on this feature.

• Security and Privacy self-review²: url

• GitHub repo: url

• Primary contacts:

  • Shunya Shishido (@sisidovski), Google.

• Organization/project driving the design: Google Chrome browser loading team.

• This work is being funded by: Google

• Incubation and standards groups that have discussed the design: WICG

• Standards group(s) that you expect to discuss and/or adopt this work when it's
  ready: WebApp WG

• Multi-stakeholder feedback³:

  • Chromium comments:
  • Mozilla comments: ServiceWorkerAutoPreload mozilla/standards-positions#1036
  • WebKit comments: ServiceWorkerAutoPreload WebKit/standards-positions#359
  • ServiceWorkerAutoPreload WICG/proposals#155 (comment)

• Major unresolved issues with or opposition to this design: so far we don't have unresolved issues.

• I have reviewed the TAG's Web Platform Design Principles

You should also know that...

• Spec change PR: ServiceWorkerAutoPreload w3c/ServiceWorker#1756
• Previous TAG review request: ServiceWorkerAutoPreload #963