How to use GTMetrix to improve Magento performance
This article describes how you can use the information in GTMetrix performance reports to help improve Magento site performance.
We strongly recommend you follow the Magento optimization steps described in this article
if you have not already done so.
If you configure the settings as described below and your site's performance is still not at the level you want, there are additional options:
GTMetrix is an online tool that analyzes site performance and speed. All you have to do is provide a URL for GTMetrix to analyze, and it generates a detailed performance report. The report contains statistics and specific recommendations you can follow to help improve your site's performance.
Running a GTMetrix performance report
To run a GTMetrix performance report for your site, follow these steps:
- Use your web browser to go to http://gtmetrix.com.
- In the Analyze Performance of text box, type the URL for your web site:
- Click GO!. GTMetrix analyzes your site.
The length of time to complete the analysis depends on how busy the GTMetrix site is at the moment, as well as your own site's speed. The entire analysis process can take several seconds up to a minute.
- After GTMetrix completes the analysis, it displays a performance report for your site.
- The Summary section provides an overall grade and some basic site statistics:
- The Breakdown section provides specific recommendations about how to improve performance, with the areas needing the most attention listed first:
Analyzing GTMetrix results
GTMetrix performance reports provide a lot of information. In the Breakdown section, the Page Speed and YSlow tabs display specific recommendations that can make a direct impact on your site's speed and performance.
GTMetrix provides a performance grade and a description for each recommendation. Some recommendations are more important than others, and have a larger impact on site speed. Recommendations that have the most effect on performance include:
- Enable gzip compression (Page Speed) and Compress components with gzip (YSlow): Enabling gzip compression reduces the size of each file the site serves. For information about how to enable compression for a Magento site, please see this article.
- Serve resources from a consistent URL (Page Speed) and Reduce DNS lookups (YSlow): The fewer domains that your site uses to serve content, the fewer times a web browser must look up where a domain is hosted. For example, as described here, at an average of 130 milliseconds per DNS lookup, four separate domains serving your content could add half of a second (or more) to the overall load time.