With Firefox's built-in session restore, tabs will usually show results from cache if the cached files have not "expired" (the server set the expiration date when Firefox originally downloaded the page). So in that case, you definitely need to reload the page to update it.

If you always want a fresh load, you could clear Firefox's cache: How to clear the Firefox cache.

Doesn't Firefox pre57 refresh tabs upon first selection? Am I mistaken?

I don't remember whether Firefox 56 and earlier used the cached page or bypassed the cache and reloaded from the server. It's been nine months!

I still run a pre-Quantum version of Firefox regularly, but I have never used any sort of "Tabs Session" extension. That said, from my perspective it worked the same in the "legacy" versions of Firefox as it does in Quantum; tabs are reloaded from the cache and need to be Reloaded from the original server, in cases where the web page has been updated.

Hi noel_envoide, do you recall ever customizing this setting:

http://kb.mozillazine.org/Browser.cache.check_doc_frequency

I don't think that browser.cache.check_doc_frequency has any effect on restoring pages via "Show my windows and tabs from last time" if you leave tabs open.

jscher2000 said

Hi noel_envoide, do you recall ever customizing this setting: http://kb.mozillazine.org/Browser.cache.check_doc_frequency

Hey 'jscher2000,

This is interesting, from http://kb.mozillazine.org/Browser.cache.check_doc_frequency

When a page is loaded, it is cached so it doesn't need to be downloaded to be redisplayed. If the page changes after a previous visit, you may want to redownload it anyway to get the updated page. This preference controls how often to check for a newer version of a cached page.

Possible values and their effects

Value set to 0 = Check for a new version of a page once per session (a session starts when the first application window opens and ends when the last application window closes).

Value set to 1= Check for a new version every time a page is loaded.

Value set to 2 = Never check for a new version - always load the page from cache.

Value set to 3 = Check for a new version when the page is out of date. (Default)

My current setting is the default "3".

So, what exactly happens by selecting "1"?

noel_envoide said

This is interesting, from http://kb.mozillazine.org/Browser.cache.check_doc_frequency ... So, what exactly happens by selecting "1"?

I haven't tested it myself, but I would expect Firefox to send a request to the server to verify that the page hasn't been updated since the last time Firefox retrieved it.

jscher2000 said I haven't tested it myself, but I would expect Firefox to send a request to the server to verify that the page hasn't been updated since the last time Firefox retrieved it.</blockquote> Yeh, that's what it looks like to me too. Thanks for the advice.

I'll let you know how it goes..