Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Firefox ver 28 or 29 slows after varying lengths of time on Windows 8.1 box.

more options

Hardware - HP Laptop Envy Windows 8.1 Firefox Version 29

Firefox slows down following launch. Slowdown occurs anywhere from 15 minutes to five hours after launch. Shutting Firefox down and restarting eliminates the slowdown issue temporarily but again the slowdown will recur in the 15 minute to five hour period. Same problem was occurring with FIrefox 28. Checking the Task Manager window FIrefox can be observed using 15 % to 25 % of CPU cycles. Shutting down Firefox and restarting it the task manager shows Firefox using only 0.5 to 5% of CPU resources. Over time this climbs until the slowdown becomes annoying. Have disabled antivirus, and removed Adobe Flash player previously. I find that Internet Explorer demonstrates the same behavior after a comparable time window.

I have tried several "FIXES" recommended on various websites but the slowdown issue persists. Suggestions, ideas, anything welcomed.

Hardware - HP Laptop Envy Windows 8.1 Firefox Version 29 Firefox slows down following launch. Slowdown occurs anywhere from 15 minutes to five hours after launch. Shutting Firefox down and restarting eliminates the slowdown issue temporarily but again the slowdown will recur in the 15 minute to five hour period. Same problem was occurring with FIrefox 28. Checking the Task Manager window FIrefox can be observed using 15 % to 25 % of CPU cycles. Shutting down Firefox and restarting it the task manager shows Firefox using only 0.5 to 5% of CPU resources. Over time this climbs until the slowdown becomes annoying. Have disabled antivirus, and removed Adobe Flash player previously. I find that Internet Explorer demonstrates the same behavior after a comparable time window. I have tried several "FIXES" recommended on various websites but the slowdown issue persists. Suggestions, ideas, anything welcomed.

All Replies (3)

more options
more options

I experience the same problem in Chrome. I've seen it eat 80% of my CPU, though it normally sits around 45% when it occurs. It's why I started migrating to Firefox. Interestingly enough, I haven't been having that problem lately - it seems to come and go.

My initial thought would be that there's some common internet protocol or software causing this. Maybe it's security-related, a botnet blindly DoSing vulnerable browsers. The Java Development Toolkit Plugin says it's vulnerable and I suspect the underlying issues are common across browsers. I have no actual information, so take what I say with salt until someone smarter chimes in.

more options

Thanks for the suggestions Guigs 2 and Redel. Some of the items had already been tried and others were items which when tried did not bring apparent change. The moe I delve into the mix the more I am convinced it is something in WIndows. It is hard to believe that Chrome, IE and Firefox would all exhibit the same behavior. Possible? Well yeah but seem unlikely to me.

Initially I suspected Adobe Flash as it also was showing high resource utilization. Hopefully some one is able to piece this puzzle together before folks start going to Linux.