No. 13
Uptime
No. 12
Google Chrome DevTools
No. 11
Website Audit
No. 10
DareBoost
No. 9
Yellow Lab Tool
No. 8
Site 24x7
No. 7
Dotcom-monitor
No. 6
Gt matrix
No. 5
WebPageTest
No. 4
Uptrends
No. 3
Google PageSpeed Insites
No. 2
Sematext
No. 1
Pingdom Speed Test