Tools to test your website’s performance

There are many developer oriented tools out there for testing web site performance. Many are free (free as in beer), some are open source (free as in speech), and a few are also subscription based.

If you are not using performance analysis tools in your development process, I highly recommend it. Tools are what take something good and make it great (including you). The main thing these tools focus on is page load time and caching performance. Reducing bandwidth also results in cost savings.  Often times the ‘problems’ these tools uncover are easy to fix.


The original innovator in this area was YSlow which started in 2007, backed by Yahoo!. YSlow is open source and operates as Chrome and Firefox plugins.


This site gets a B performance grade. I can live with that.  Everything I’m getting an ‘F’ on is either out of my control or overkill for a personal blog.  For example, gzip is now allowed with this hosting plan. The gravatar images don’t have an expires header set (that amazes me).  Also, I’m not going to the trouble of setting up a CDN to serve images for my blog.

I was able to address the Etags and most of the Expires Header warnings by adding this to .htaccess:

#disable etags
FileETag none

#set expires headers
ExpiresActive On
ExpiresByType image/gif "access plus 7 days"
ExpiresByType image/jpg "access plus 7 days"
ExpiresByType image/jpeg "access plus 7 days"
ExpiresByType image/png "access plus 7 days"
ExpiresByType image/x-icon "access plus 7 days"
ExpiresByType image/ico "access plus 7 days"
ExpiresByType application/javascript "access plus 7 days"
ExpiresByType application/x-javascript "access plus 7 days"
ExpiresByType text/javascript "access plus 7 days"
ExpiresByType text/css "access plus 7 days"


Alternatives to YSlow:

Keep in mind, YSlow runs from your machine, so the effect of any proxies on your network will throw the results. This is where external cloud based tools come in. The following tools do pretty much the same thing as YSlow, looking at site load time, JavaScript/CSS evaluation, use of CDNs, etc.

Pingdom Site Tools:

What I love about this tool is it captures DNS lag time in addition to download and processing time from up to 3 different geographically distant servers. I’m a fan/customer of pingdom’s alert service. There is a checkbox to make the results private.


 Other Site Analysis Tools:

  • -> Very similar to YSlow and Pingtom Tools
  • -> More of a network / file size analysis.

  • – results are generally public but you can download and run this program on your own server if you want. Very useful if you have lots of websites to check and want to automate that process.


Going beyond just page load time:

HTML Validator:

Complete suite:

  • Combines site speed test, ranking, SEO evaluation, social media evaluation, HTML validation. Woo is right, but you only get to run one site evaluation per week for free (bah)…
  • I’m impressed, but it is spendy.

Other tools I have bookmarked or use on a regular basis:

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