The browsers and connection bandwidths available in your Synthetic settings

Default browsers

SpeedCurve provides the following browsers to test with:

BrowserNetworkViewportDisplay DensityCPU Slow Down Factor
Desktop FastWifi Fast1366 x 7681X0
Desktop SlowWifi Slow1366 x 7681x0
Mobile FastMobile 4G Fast390 x 6632X0
Mobile MediumMobile 4G Fast390 x 6632X2
Mobile SlowMobile 4G Slow390 x 6632X3

These profiles don't reference specific emulated hardware, e.g. "iPhone 15" or a particular browser like "Chrome" or "Firefox". They are designed to be a great place to start your web performance testing and provide long-lived browser profiles with names that don't age. We will periodically update these profiles as web performance trends change.

Browser version

We update our browser versions during a scheduled test agent update approximately every 4-6 months. You can see the browser version that was used to run a test at the top of each test result page :


The connection for our tests is throttled to emulate the average bandwidth of users. When adding a Custom Browser you can adjust the connection speed to emulate slower mobile or faster fiber connections.

Wifi Fast80 Mbps40 Mbps10 ms
Fibre19.5 Mbps4.9 Mbps4 ms
Wifi Slow10 Mbps10 Mbps40 ms
Cable5 Mbps1 Mbps28 ms
Mobile 4G LTE12 Mbps12 Mbps70 ms
Mobile 4G Fast9 Mbps9 Mbps150 ms
Mobile 4G9 Mbps9 Mbps170 ms
Mobile 4G Slow1.6 Mbps0.8 Mbps150 ms
Mobile 3G1.6 Mbps0.8 Mbps300 ms

Emulated devices



These old emulated device test profiles have been deprecated and will not be included when adding new teams. If you need to recreate these old browsers you can do so by adding a Custom Browser and referencing the settings below.

DeviceNetworkViewportDisplay DensityCPU Slow Down Factor
Apple iPadWiFi768x10242X1.8
Apple iPhone 5Mobile 3G320x5682X3
Apple iPhone 6Mobile 3G375x6272X2.6
Apple iPhone 7Mobile 4G375x6672X1.2
Apple iPhone 8Mobile 4G LTE375x6672X0
Apple iPhone XMobile 4G LTE375x8123X0
Google Nexus 6Mobile 3G412x6593.5X2.9
Google Nexus 7Mobile 3G600x9602X3.1
Google Nexus 10Mobile 3G800x12802X3
Google PixelMobile 4G411x7312.6X2.4
Google Pixel 2Mobile 4G LTE411x7312.6X2.2
Samsung Galaxy S IIIMobile 3G360x6402X3.2
Samsung Galaxy S4Mobile 3G360x6403X3.1
Samsung Galaxy S7Mobile 4G360x6403X2.3
Samsung Galaxy S8Mobile 4G LTE360x7404X2.2