content/browser/prerender/README.md - experimental/chromium/src - Git at Google

 This directory contains the experimental Prerender2 implementation
 (https://crbug.com/1126305). This feature is now behind the
 `blink::features::kPrerender2` flag.

 If you're interested in relevant code changes, join the
 prerendering-reviews@chromium.org group.

 # Summary

 Prerendering is "pre"-rendering, it's about pre-loading and rendering a page
 before the user actually navigates to it. The main goal of prerendering is to
 make the next page navigation faster, or ideally nearly instant.

 The Prerender2 is the new implementation of prerendering.

 # Terminology

 - **Trigger**: "Trigger" is an entry point to start prerendering. Currently,
   `<link rel=prerender>` is the only trigger.
 - **Activate**: The Prerender2 runs navigation code twice: navigation for
   prerendering a page, and navigation for displaying the prerendered page.
   "Activate" indicates the latter navigation.
 - **Legacy Prerender**: "Legacy Prerender" is the previous implementation of
   prerendering that does not use NoStatePrefetch. This is already deprecated
   (https://crbug.com/755921).
 - **NoStatePrefetch**: An internal mechanism for speculative prefetching of
   pages and their subresources that are on a critical path of page loading
   without executing any JavaScript or creating a complex state of the web
   platform (https://www.chromestatus.com/feature/5928321099497472). This
   mechanism is not purely "no state" because the HTTP cache allows to create
   cookies and other state related to validating cache entries. The current
   prerendering uses this mechanism, that is, it does not actually render pages,
   while the Prerender2 renders pages.

 # References

 The date is the publication date, not the last updated date.

 - [Prerender2](https://docs.google.com/document/d/1P2VKCLpmnNm_cRAjUeE-bqLL0bslL_zKqiNeCzNom_w/edit?usp=sharing) (Oct, 2020): Introduces how Prerender2 works and more detailed designs such as Mojo Capability Control.
	This directory contains the experimental Prerender2 implementation
	(https://crbug.com/1126305). This feature is now behind the
	`blink::features::kPrerender2` flag.

	If you're interested in relevant code changes, join the
	prerendering-reviews@chromium.org group.

	# Summary

	Prerendering is "pre"-rendering, it's about pre-loading and rendering a page
	before the user actually navigates to it. The main goal of prerendering is to
	make the next page navigation faster, or ideally nearly instant.

	The Prerender2 is the new implementation of prerendering.

	# Terminology

	- Trigger: "Trigger" is an entry point to start prerendering. Currently,
	`<link rel=prerender>` is the only trigger.
	- Activate: The Prerender2 runs navigation code twice: navigation for
	prerendering a page, and navigation for displaying the prerendered page.
	"Activate" indicates the latter navigation.
	- Legacy Prerender: "Legacy Prerender" is the previous implementation of
	prerendering that does not use NoStatePrefetch. This is already deprecated
	(https://crbug.com/755921).
	- NoStatePrefetch: An internal mechanism for speculative prefetching of
	pages and their subresources that are on a critical path of page loading
	without executing any JavaScript or creating a complex state of the web
	platform (https://www.chromestatus.com/feature/5928321099497472). This
	mechanism is not purely "no state" because the HTTP cache allows to create
	cookies and other state related to validating cache entries. The current
	prerendering uses this mechanism, that is, it does not actually render pages,
	while the Prerender2 renders pages.

	# References

	The date is the publication date, not the last updated date.

	- [Prerender2](https://docs.google.com/document/d/1P2VKCLpmnNm_cRAjUeE-bqLL0bslL_zKqiNeCzNom_w/edit?usp=sharing) (Oct, 2020): Introduces how Prerender2 works and more detailed designs such as Mojo Capability Control.