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