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Autoptimize

By Optimizing Matters

Performance & Optimization / Caching Solutions

Autoptimize Review - In-Depth Analysis

Autoptimize speeds up your website by optimizing JS, CSS, images, HTML, and Google Fonts. It also supports lazy-loading and asyncing JS.

Performance Overview

WPS Score

7.37/10

User Rating

4.7/5 (based on 1426+ reviews)

Active Installations

800,000+

Update Frequency

Very Good It is calculated using the weighted average of same category plugins.

Security Score

1 / 10 (Very Low Risk) It is calculated using the weighted average of all versions.

What It Does

Autoptimize makes optimizing your site really easy. It can aggregate, minify and cache scripts and styles, injects CSS in the page head by default but can also inline critical CSS and defer the aggregated full CSS. It moves and defers scripts to the footer and minifies HTML.

You can optimize and lazy-load images with support for WebP and AVIF formats, optimize Google Fonts, async non-aggregated JavaScript, and remove WordPress core emoji cruft. As such, it can improve your site's performance even when already on HTTP/2.

There is extensive API available to enable you to tailor Autoptimize to each and every site's specific needs. If you think performance indeed is important, you should at least consider one of the many free page caching plugins to complement Autoptimize or even consider Autoptimize Pro, which not only has page caching but also image optimization, CDN, critical CSS, and more.

Comparing to Alternatives

Autoptimize is a popular plugin focused on optimizing CSS, JS, and HTML to improve website performance. Compared to other optimization plugins, it offers a robust set of features with a focus on minification and aggregation.

Top alternatives

Strengths

Effective minification and aggregation of CSS, JS, and HTML files
User-friendly interface with straightforward setup
Strong community support and frequent updates
Includes options for async and defer loading of scripts

Weaknesses

Does not include integrated caching, requiring a separate caching plugin
Some users report compatibility issues with certain themes or page builders
Pro version can be costly relative to free alternatives

User Sentiment Analysis

User feedback on Autoptimize highlights both its effectiveness and some challenges encountered during use.

Positive highlights

"Just a few clicks and the site goes to 90% and B at GTMetrix 🙂" - Mittsforcode
"Useful plugin and great free support" - MarcGuay
"We've been using this plugin for literally about a decade now... Support is prompt, personal, and amazing." - thefitrv
"Fantastic plugin for optimizing CSS and JS! Reduced load time by almost 30%." - juanmag
"Perfect, fast Support!" - Peter Kinny

Common complaints

Creates excessive cache files, sometimes very large in size
Can break CSS and page layouts, especially on homepages
Sends unsolicited emails about cache issues
Requires additional caching plugin for full performance

Weaknesses

Cache management can be problematic leading to large storage use
Compatibility issues with some themes and page builders like Elementor

Who Should Use This?

Best for

Website owners and developers looking for a powerful and easy-to-use plugin to minify and optimize CSS, JS, and HTML files to improve site speed.

Not ideal for

Users seeking an all-in-one caching and optimization solution or those unfamiliar with troubleshooting potential compatibility issues may find this plugin less suitable.

Pricing & Value

Free version includes

The free version offers comprehensive minification and aggregation of CSS, JS, and HTML, along with options for async and defer loading, providing significant performance improvements.

Pro version

The premium version adds advanced features such as image optimization, critical CSS generation, and priority support to further enhance website speed and user experience.

Final Verdict

Autoptimize is a highly effective plugin for optimizing front-end assets, improving load times significantly when configured correctly.

While it excels at minification and aggregation, users should be aware of potential cache management issues and the need for a separate caching plugin for best results.

Other Notable Features

Here are a few other notable features of this free Autoptimize plugin.

Performance

Optimize

Pagespeed

FAQ

It minifies all scripts and styles and configures your webserver to compresses them with good expires headers. JavaScript be default will be made non-render-blocking and CSS can be too by adding critical CSS. You can configure it to combine (aggregate) CSS & JS-files, in which case styles are moved to the page head, and scripts to the footer. It also minifies the HTML code and can also optimize images and Google Fonts, making your page really lightweight.

Autoptimize supports this, but it is not enabled by default because non-local fonts might require some extra configuration. But if you have your cross-origin request policy in order, you can tell Autoptimize to put your fonts on the CDN by hooking into the API, setting autoptimize_filter_css_fonts_cdn to true this way;

add_filter( 'autoptimize_filter_css_fonts_cdn', '__return_true' );

Domain mapped multisites require Autoptimize to be initialized at a different WordPress action, add this line of code to your wp-config.php to make it so to hook into setup_theme for example:

define( 'AUTOPTIMIZE_SETUP_INITHOOK', 'setup_theme' );

Yes, if you want to serve files from e.g. /wp-content/resources/aggregated_12345.css instead of the default /wp-content/cache/autoptimize/autoptimize_12345.css, then add this to wp-config.php:

define('AUTOPTIMIZE_CACHE_CHILD_DIR','/resources/'); define('AUTOPTIMIZE_CACHEFILE_PREFIX','aggregated_');

As from AO 2.4 AO “listens” to page cache purges to clear its own cache. You can disable this behavior with this filter;

add_filter('autoptimize_filter_main_hookpagecachepurge','__return_false');

By default AO uses non multibyte-safe string methods, but if your PHP has the mbstring extension you can enable multibyte-safe string functions with this filter;

add_filter('autoptimize_filter_main_use_mbstring', '__return_true');

Autoptimize caches aggregated & optimized CSS/ JS and links to those cached files are stored in the HTML, which will be stored in a page cache (which can be a plugin, can be at host level, can be at 3rd party, in the Google cache, in a browser). If there is HTML in a page cache that links to Autoptimized CSS/ JS that has been removed in the mean time (when the cache was cleared) then the page from cache will not look/ work as expected as the CSS or JS were not found (a 404 error).

This setting aims to prevent things from breaking by serving “fallback” CSS or JS. The fallback-files are copies of the first Autoptimized CSS & JS files created after the cache was emptied and as such will based on the homepage. This means that the CSS/ JS migth not apply 100% on other pages, but at least the impact of missing CSS/ JS will be lessened (often significantly).

When the option is enabled, Autoptimize adds an ErrorDocument 404 to the .htaccess (as used by Apache) and will also hook into WordPress core template_redirect to capture 404’s handled by WordPress. When using NGINX something like below should work (I’m not an NGINX specialist, but it does work for me);

location ~* /wp-content/cache/autoptimize/.*\.(js|css)$ {     try_files $uri $uri/ /wp-content/autoptimize_404_handler.php; }

And this a nice alternative approach (provided by fboylovesyou);

location ~* /wp-content/cache/autoptimize/.*\.(css)$ {     try_files $uri $uri/ /wp-content/cache/autoptimize/css/autoptimize_fallback.css; } location ~* /wp-content/cache/autoptimize/.*\.(js)$ {     try_files $uri $uri/ /wp-content/cache/autoptimize/js/autoptimize_fallback.js; }