Compare Websites Loading Speed (Side-by-Side) with This Tool

By Jake Rocheleau. in Toolkit. Updated on September 18, 2022.

It’s no secret that a website’s load time is a huge factor in usability. This also affects your site’s Google rankings, so your page speed is definitely worth optimizing.

If there’s a competitor you’re trying to outrank, one metric you might analyze is page speed. And, with a tool like Duoload, you can check the speed of two pages simultaneously, right from your browser.

This is one of the few tools I’ve found where you can study page loading times together in a single window. You can watch how they render and which page elements load first on both sites.

The loading process is controlled through a single button, so you press it once to load both websites at the same time. Pretty neat!

I would love to see an extra feature to set a custom proxy or IP to load from different countries. But for now, you can only get this to work if you run traffic through a VPN.

Still, Duoload is quite valuable because it also lets you browse around the websites to see the difference in page speeds. This way you can gauge the overall user experience between two different sites and check your site against other competitors.

This is a super basic web app but it leaves plenty of room for customization.

You can find all the source code for free on GitHub to download a copy and even host it yourself. This lets you edit the app to include any changes to the JavaScript for tracking load times, large HTTP assets, and even adding a 3rd website pane into the mix.

If you have suggestions for extra features or want to share some love, you can always drop a line to the creator Lea Verou on her Twitter @LeaVerou.