This is a step-by-step guide/tutorial with images on how to install, setup, configure and use the free version of ‘Autoptimize’ WordPress plugin.

It is in use by 1+ million active websites with 4.5 star review rating.

The ‘Autoptimize’ is of the most popular WordPress plugin to increase your WordPress website loading time. Learning how to speed up WordPress is very important since the mobile use of internet is increasing each year. WordPress performance optimisation cache plugins are a one way solution.

Optimising your WordPress theme and page settings will improve much more your WordPress website speed. The less website elements are loaded, the faster your website becomes.

How to Install Autoptimize

To install, go to ‘Plugins > Add New’ and on the top right corner next to ‘Keyword’ type ‘Autoptimize’. Wait for the plugin to appear and then click its ‘Install Now’ button. Wait again until you see the its ‘Activate’ button and click it.

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In the side WordPress menu, go to ‘Plugins’, find ‘Autoptimize’ plugin, click its settings link.

autoptimize wordpress plugin guide tutorial how to install


Autoptimize Plugin Settings Tab: JS, CSS & HTML

Go to the tab ‘JS, CSS & HTML’ and activate the following options:

Javascript options: ‘Optimize JavaScript Code’ + ‘Aggregate JS-files

These options will find the javascript files from plugins and other sources and combine them into one file. That results in loading less website elements for faster loading. Javascript is related with functions and automation of code.

CSS options: ‘Optimize CSS Code‘ + ‘Aggregate CSS-files‘.

These options will find the themes CSS files. That results in loading less website elements for faster loading. CSS is related with visuals like fonts, colors and layout.

HTML options: ‘Optimize HTML Code’

CDN options: Enter here the URL provided by your CDN provider (if you have activated it on your hosting provider server or purchased it elsewhere). CDN (Content Delivery Network) is a service that optimises website loading time for worldwide visitors. The CDN url might look like this:



The characters ‘//’ are used if some of your website links start with https and some with http (mixed content).

CDN options: It is better that you don’t activate them until you compelte all your optimisations and check them with speed tools (GTmetrix). Then activate Misc Options one by one and test 3X with GTmetrix.

Click ‘Save Changes and Empty Cache‘.

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Autoptimize Plugin Settings Tab: Images

Image Optimization is a useful feature to avoid installing more plugins for that purpose. Test it in the final optimisation stage to see if speed results are good.

Click ‘Save Changes’ if you made changes.

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Autoptimize Plugin Settings Tab: Extra

Activate ‘Remove emojis‘. This improves speed without negative impact.

If you want a fast site, then don’t use Google fonts or use activate the option ‘Leave as is‘.

To improve the visual style of your website you have to use Google fonts, but this will slow down your website. You can try to compensate by activating the rest of the option. Use GTMetrix to see which option is best while also checking how you website looks while it’s loading.

Click ‘Save Changes’.

autoptimize wordpress plugin guide tutorial extra auto optimizations


The tab ‘Critical CSS’ is not a free feature.

CDN Setting Verification

To make sure that you CDN configuration works ok, open your website and force reload it by pressing Ctrl+F5 . Open its source code with the keyboard shortcut Ctrl+U. Check if the text/image links contain the CDN URL you entered in ‘CDN Based URL’.


There are many additional options that you can activate but the results are never the same for all website owners. The results of using additional settings depend on the server type, theme and theme user settings, plugins and scripts. Therefore its better to activate one and then run a speed test and also check your website functionality for strange behavior. Each time your activate one setting run the speed testing 3 times.

How to Check Autoptimize Speed Optimisation Results

To test the results of your settings, use website speed tools like GTmetrix, Google PageSpeed Insights, Pingdom Tools or WebPageTest. GTmetrix produces realistic results and includes the function Waterfall (tab) to see a number of elements loaded and their loading time.

Speed Testing Considerations

1. Start by using the default recommended settings of the plugin.

2. Run GTmetrix website speed and performance optimization testing tool to analyse website loading time. Run Gmetrix on a specific website page 3 times to get a realistic analysis.

3. Make one more setting change/addition in the plugin and repeat step 2.

4. Check the GTmetrix Waterfall tab to see which website elements load. Inspect their size and loading time. Try to reduce website the number of website elements and their size.

5. Use only the necessary tracking scripts since they really affect loading time.

6. Don’t install too many or slow plugins.

7. Use image lazy loading to improve speed.

8. Reduce image size with compression before you load it on your website page.

9. Use default fonts instead of google fonts, if possible.

10. Prefer gif images since they are smaller in size, if possible.


There are many WordPress cache plugins and methods to reduce loading time. Speed improvement is important but don’t waste too much time of speed optimisation. Try to get the website loading within 3 seconds and focus mostly on content creation and promotion.

Website performance also depends on hosting package. VPS and cloud hosting is faster that shared hosting. Some hosting providers provide features like varnish, OP cache and Redis that improve loading speed even further.

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