How to simulate limited bandwidth in Google Chrome and Firefox

Your development machine is usually on a very good network connection.
To test how your application behaves on a slow network (e.g. mobile), you can simulate limited bandwidth.

Chrome

• Open the dev tools (Ctrl+Shift+I or F12) and switch to the "Network" tab
• In the row below the dev tool tabs, there's a throttling dropdown which reads "Online" by default.
• Inside the dropdown, you will find a few presets and an option to add your own download/upload/latency settings.

Firefox

• Open the dev tools (Ctrl+Shift+I or F12) and switch to the "Network" tab
• On the right of the row right below the dev tool tabs you will find an option which reads "No throtteling" by default.
• Pick one of the presets available there.

(Almost) any application: trickle

There is a Linux utility called "trickle" that allows you to do limit the bandwidth available to a process.

You may need to install it first. For example, on Ubuntu:

Copysudo apt-get install trickle

To start an application with limited downstream or upstream, run it through trickle. Example:

Copytrickle -d 50 -u 20 firefox

This will start a Firefox process which is limited to 50 kB/s download and 20 kB/s upload.

Note that this will not work on some applications (e.g. Chrome).

Simulating limited CPU power

Note that mobile devices often also have limited CPU resources. We have a separate card about that.