Website Performance and Network Tools
Check how a website loads and responds: page speed and Core Web Vitals, page weight, mobile-friendliness, whether a site is up, and IP address details. These checks run from our server (or through Google PageSpeed Insights, where stated), so they test the site from outside your own network.
- 100% freeNo sign-up needed
- Clear about data2 of 9 run in your browser
- Instant resultsNothing to install
Speed and page weight
Measure how fast a page loads and what it weighs.
Website Speed Checker
Test page speed and Core Web Vitals with PageSpeed Insights.
Uses our server
Page Size Checker
Measure HTML size, compression and total page weight.
Uses our server
Mobile-friendliness
See how a page looks and behaves on phones.
Mobile-Friendly Test
Check a page's viewport, text size and layout on phones.
Uses our server
Cross Browser Tester
Preview a page at phone, tablet and desktop sizes side by side.
Uptime and outages
Check whether a website is up or down right now.
Is It Down? Website Down Checker
Check if a website is down for everyone or just you.
Uses our server
Website Uptime Checker
Check if your site responds right now, with status and timing.
Uses our server
Network and browser information
See your IP address, browser and connection details.
IP Address Lookup
See your public IP or look up any IP's country and network.
Uses our server
What Is My Browser?
See your browser, version, OS, screen size and user agent.
Also useful here
Tools from other categories that fit this job.
HTTP Status Checker
Check status codes, headers and response time for one or 20 URLs.
SEO tools Uses our server
No tools in this category match your filter. Try the all tools page.
What these checks can and can't tell you
A check shows the result for one request, from one location, at one moment. If a site is "down" for you but "up" in our check, the problem is likely your connection, DNS or a regional outage. If a check fails for us too, the site is probably down for everyone. For ongoing monitoring with alerts, use a dedicated uptime-monitoring service; these tools are for spot checks.
Questions about website performance tools
Common questions from people using these tools.
Do these tools measure my website traffic?
No. None of these tools measure visitor numbers. For traffic, use your analytics or Google Search Console. These tools measure speed, availability and technical details.
Where are the checks run from?
From our web server. The speed test uses Google PageSpeed Insights, which runs Lighthouse on Google's infrastructure and adds real-user data from the Chrome UX Report when Google has enough of it.
What's the difference between an uptime check and monitoring?
A check tests the site once, when you click. Monitoring repeats the check every few minutes and alerts you when it fails.