This website is hosted on a German server and I don’t currently use a CDN. So German visitors should be getting the quickest performance timings. But what about my homies in Cali or elsewhere?
I went to WebPagetest and tested a page containing the most resources using “Motorola G (gen 4)” mobile browser emulation and a “3G Fast” connection.
The Page is Rendered Quickest Outside of the Host Country. How Can That Be?
As expected, the time to first byte is shortest in Germany – that’s where I host my site.
But tests run from three locations outside of Germany (Isreal, San Francisco and Dulles, Virginia) were visually complete before the German test.
In fact, the visual progress of German test was pretty average compared to the other test locations.
Apparently, the test from Dulles, VA was fastest to visually complete.
That seemed odd. If the physical distance between host and client is shortest in Germany, then shouldn’t the page finish rendering the quickest there?
More Bytes Sent to Dulles, VA
Then I had a look at Image Bytes and noticed: way more image bytes were being sent to Dulles, VA.
That’s when I realized:
If you test from “Moto G (gen 4)”, you’re testing on a real device – even if you select Browser Emulation.
Indeed, when comparing test results from "Moto G (gen 4)” and “Virginia USA - EC2” (both with browser emulation), you see more image bytes are downloaded and an additional image request.
And performance timings around the board are better for "Moto G (gen 4)” than “Virginia USA - EC2”.
I then compared test results using only device emulation (no real devices) and Bytes and Requests were the same:
Lessons Learned
Testing my website from around the world using WebPagetest taught me:
- When testing from various locations around the world, make sure you use emulation only – no real devices.
- Testing on real devices will of course give you more realistic performance timings than on emulated devices, but if you’re using public WebPagetest, the test location is Dulles, VA.