User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:55.0) Gecko/20100101 Firefox/55.0 Build ID: 20170523100217 Steps to reproduce: network.http.speculative-parallel-limit;0 network.predictor.enable-prefetch;false network.predictor.enabled;false network.prefetch-next;false Normal websites do not make speculative connections on hovering a link. Have I missed something?
STR: open about:networking and hover elements on about:newtab
Connections are probably made to take thumbnails.
(In reply to Loic from comment #2) > Connections are probably made to take thumbnails. Thank you for your hint! I thought thumbnails/screenshots would be made on my first visit of an url (which is present on the newtabpage) and then get saved on the harddisk until a new thumbnail would be made when I revisit that url and some timer has elapsed. And if I place a bookmark there for which no thumbnail is available, a pref decides wether to load it in the background to make a thumbnail or to let it blank until I visit it (this bug is about that). But this pref, for example, has not that behavior: https://hg.mozilla.org/integration/mozilla-inbound/rev/9ca23d313302#l1.12 > // enables showing basic placeholders for missing thumbnails > pref("browser.newtabpage.thumbnailPlaceholder", false); I think this pref should also decide about renewing a thumbnail only on click (uBlock Origin might set this with its disable-all-prefechting option) or on hover (default, current behavior).