useless, not working Rated 1 out of 5 stars

by Tarun Mahashwari on March 19, 2017 ·

worst add on

Literally does nothing Rated 1 out of 5 stars

by Joe on Feb. 1, 2017 ·

This plugin must have been killed off a while back. It literally does nothing after you install it. There isn't even a button to click to run the plugin.

This user has a previous review of this add-on.

Rated 1 out of 5 stars

by Kekkyojin on Jan. 11, 2017 ·

Stopped working.

Furthermore, it will need to be moved into Firefox DevTools instead of Firebug

Not working in FF50 Rated 1 out of 5 stars

by iVipera on Jan. 10, 2017 ·

Its not working in firefox 50.

Wastage of Time Rated 1 out of 5 stars

by Muhammad Idrees on Dec. 6, 2016 ·

stupid add-on. does not install.

does not work Rated 1 out of 5 stars

by EthernetGuru on Sept. 22, 2016 ·

does not work in v51 nightly.

Do`nt work in FF48 Rated 1 out of 5 stars

by nikello on Sept. 16, 2016 ·

Do`nt work in FF48

Everything working FF 48.0 Rated 5 out of 5 stars

by labzzzz on Aug. 12, 2016 ·

Enter this url in FF about:addons.
Then click on YSlow Prefencies and check first checkbox. Then, when u'll reload u page, it would work!

Not working Rated 1 out of 5 stars

by Lautaro on July 5, 2016 ·

In FF 47

Worst Experience Ever Rated 1 out of 5 stars

by sanjeev on June 30, 2016 ·

This addon is a total waste of time. Not only is this useless because when you finally get to access it - clicking on the "Run Test" doesnt respond, it also irritates you while installing it and figuring out where to find it - ie, inside firebug!

Complete and Utter waste of time ever.

Dead Rated 1 out of 5 stars

by mikkok on June 29, 2016 ·

This used to be a great addon but has not worked in a very long time. Mozilla should just pull it off the site already.

Does not work Rated 1 out of 5 stars

by Sphawk on June 19, 2016 ·

with Firefox 47

Does not work Rated 1 out of 5 stars

by Dennis on May 28, 2016 ·

with Firefox 46.

Does not work Rated 1 out of 5 stars

by Jaym3s on May 26, 2016 ·

FF 46.0.1

It mostly works for me in FF 46.02! Rated 4 out of 5 stars

by stormybeach on May 26, 2016 ·

In Firefox, go to Add-ons, then Extensions, then see Yslow. Click options and click "Automatically run YSlow when page finishes loading." It will give the overall rating plus the element ratings, but the elements themselves are still not clickable. Great insight anyway.

Not Working Rated 4 out of 5 stars

by docenttmp on May 2, 2016 ·

FF 45 - Yslow was broken

It dosen't work Rated 1 out of 5 stars

by web-dev on April 23, 2016 ·

there isn't anything work,click yslow there isn't anything happen

Not working Rated 1 out of 5 stars

by mikethevike84 on Feb. 25, 2016 ·

Installed for Firefox 44.0.2 - doesn't run.

Broken Rated 1 out of 5 stars

by xxclixxx on Jan. 29, 2016 ·

Used to work great, but seems to be broken.

YSlow Workaround! Rated 1 out of 5 stars

by Michael on Jan. 19, 2016 ·

It's clear from this very long thread YSlow isn't working anymore with current FF versions. However there's hope!

These three sites will give the web page speed info desired and more: gtmetrix.com | host-tracker.com | webpagetest.org

gtmetrix.com has both PageSpeed and YSlow operating.