Almost half of the top 1000 retail websites don’t follow two easy performance best practices. Does yours?

I’m hip-deep in data from a big research project (the topic is still under wraps) that we’re working on here at Strangeloop. We’ve been studying the top 1000 online retailers, and we noticed a trend so significant that it merits some attention of its own.

Check out these charts showing how the top 1000 retail sites rated with two page speed scores: Keep-alive Enabled and Compress Text.*

Alexa Retail 1000: Page speed score for keep-alivesAlexa Retail 1000: Page speed scores for text compression

Summary

  • 85% of these sites use keep-alives.
  • 53% do compression.
  • But when I overlaid these two sets of numbers, I was surprised to find that 47% don’t do one or the other.

These are two of the easiest, lowest-hanging fruit on the performance optimization tree, and almost half of the leading retail websites aren’t taking advantage of them simultaneously.

Keep-Alives

TCP connection is the process by which both the user and the server send and receive acknowledgment that a connection has been made and data can begin to be transferred. Too many TCP connections will slow down your site. It’s not easy to speed up TCP connection, but you can control how many times the connection takes place.

If you’re an exec/marketing manager: First, test your site and get its keep-alive score. If it’s anything less than an A, then take a look at your site’s waterfall chart. (Here’s a quick primer on how to interpret this chart.) If you’re seeing a lot of orange bars, you have a problem that could be fixed by using keep-alives.

If you’re in dev/ops: Make sure you have the proper configuration on your servers and load balancer. Also, we saw a number of CDNs that don’t do keep-alives properly, so keep your eyes open for lots of orange bars on content coming from your CDN.

Compress Text

The average size of the web pages we studied is 836kb, which is a major slowness factor. Compressing resources can reduce the number of bytes sent over the network. Text compression isn’t the only way to reduce your payload, but it is the easiest.

If you’re an exec/marketing manager: As above, test your site and get its compress text score, then check out its waterfall chart. If you’re seeing a lot of bright blue bars, you have a problem that could be fixed through compression.

If you’re in dev/ops: Make sure you’re following Google’s best practices for compression, as outlined here.

Don’t underrate these two simple measures.

They can have a huge impact on page speed. In a session where I first de-optimized, then re-optimized, the Velocity website, the first fixes I implemented were keep-alives and text compression. With just these two fixes, the site experienced major improvements in these areas:

  • Start render: 52% faster
  • Document complete: 40% faster
  • Fully loaded: 31% faster

These two steps alone are not enough, but they’re definitely must-haves before you reach for the fruit on the higher branches.

*All tests conducted on Webpagetest — IE7 on DSL via the server in Dulles, VA.

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