Chrome DevTools: Custom Network Throttling Profiles

Introduction

DevTools supports Network throttling (and even CPU Throttling). The built-in presets for Network Panel Throttling are essentially Fast 3G, Slow 3G and Offline.

This tip is to demonstrate that you can create your own throttling presets, where you can customise the speeds for download, upload and latency.

How to use this feature

1. Go to Settings > Throttling.
2. Select Add a custom profile.
3. Enter a Profile Name, Download speed, Upload speed and Latency.
4. You can apply your new throttling profile from the Network Panel throttle options.

Worth knowing

You can add more nuanced throttling profiles, for example:

• A profile to match a train journey where the connection is fast, yet flakey.
• A profile to match regular download speeds, but slow upload speeds - as is the case with some ISPs around the world.
• A profile to match slow speeds and high latency, to simulate the experience for some people in rural areas.

As for definitions:

• Network throttling artificially limits the maximum download throughput (rate of data transfer).
• Latency manipulation enforces a minimum delay in connection (RTT).

Extra resource

CPU Throttling is useful to apply when testing website performance - especially if you're testing on a high-end developer machine.