Slow It Down

Simulate slow networks; gain empathy

Sometimes I remind myself of the difference between sympathy and empathy. Sympathy is pity. Empathy is feeling the same thing as someone else.

A man waits on a rural porch for a website to load on his Dell laptop.

Load already! 1

Are you a web developer? You have a superfast machine and business-class cable or fiber Internet at work. You don’t wait for the Internet; the Internet waits for you.

Are you a designer? Your mock-ups have zero latency in Photoshop (if we disregard its constant crashes). So are the prototypes developers implement and show to you at the office.

The story is different for your users.

Speed still matters. Perhaps more than ever. It’s almost impossible for any web page to load in under a second when it’s loading into the palm of a hand belonging to a body waiting at a bus stop.2

Fortunately, you don’t need to leave the office to gain empathy for users on slow networks.

How to Simulate Slow & Unreliable Networks

I have three tips for three different scenarios. Get ready to empathize!

  1. Is testing low-bandwith scenarios in Google Chrome enough? Chrome now has a built-in throttling tool.

  2. Would you like to test in any browser, and not only reduce your bandwidth, but also insert latency, delayed DNS lookups, and even dropped packets? Try Network Conditioner, which Apple provides via XCode.3 Here are some installation instructions current for OS X 10.10 Yosemite.

  3. To test slow networks on other devices, such as phones, tablets, and your colleagues’ computers, you may want to look into the command-line tool Throttle.

Designers & Product Managers

Please don’t think that worrying about speed is someone else’s job. As a designer or product manager, the entire experience is your responsibility, and the choices you make can affect performance at least as much as a developer’s.

You can also ask your favorite command-line-literate collaborator or QA engineer to set up the aforementioned Throttle so that you can empathize from any device you please.


A suggestion: Do not ship new features or redesigns until they have been tested on slow networks. Make it a rule.

A final quote

Brad Frost has been quoted as saying, “Ultimately, performance is about respect.”

I love that. Use your new empathic powers to gain respect for your customers and visitors today.

  1. Animation based upon a photo by beccaplusmolly, originally entitled “grouchy slow internet face: james getting impatient…”, used and remixed with permission. (Thanks!) ↩︎

  2. Or worse yet, a subway station. ↩︎

  3. It does not throttle requests made to your own computer, though, so be aware of that while developing locally. (Hurray for staging servers.) ↩︎

July 13th, 2013. (Updated: December 08, 2014 at 1:47pm.)
Alan Hogan (@alanhogan_com).  Contact · About