“My site loads 40 CSS files, but I can barely see any of those elements on the home page” — that sentence comes up in almost every page speed consultation I do, usually with Elementor or Divi sites. The culprit is almost never the theme, but the sum of all active plugins dutifully loading their CSS and JavaScript on every page — including where they are not needed at all. Three tools address exactly this problem, but in completely different ways: Autoptimize, Asset CleanUp and WP Rocket. One thing up front: these are not three interchangeable caching alternatives. Autoptimize and Asset CleanUp do not replace a caching plugin — in practice they usually run in addition to WP Rocket, LiteSpeed Cache or another cache layer. WP Rocket, by contrast, already brings its CSS/JS optimisation built in. Here is my assessment of when each tool makes sense.
The three tools at a glance
Autoptimize (free, open source): the classic among asset optimisers, in the WordPress directory for over ten years. It aggregates, minifies and caches CSS, JavaScript and HTML, moves scripts to the footer, can optimise Google Fonts and lazy-load images. Very lean, very focused — it deliberately does no page caching and has no intention of doing so.
Asset CleanUp (free tier plus Pro from around $49/year for one site, $79 for three sites, $149 for unlimited sites, as of 2026): its distinguishing feature is per-page control. For each post or page you can see exactly which plugin loads which CSS/JS, and switch off individual files in a targeted way — for example the contact form CSS on pages without a form. For page-builder-heavy sites with a lot of plugin ballast this is often the single biggest lever there is.
WP Rocket (paid, entry level $59/year for one site, as of 2026): the all-in-one caching plugin that I have already covered in detail in WP Rocket vs Perfmatters vs LiteSpeed Cache. This article is not about caching, but specifically about the built-in CSS/JS optimisation: minification, Delay JavaScript Execution and Remove Unused CSS. The right choice for anyone who does not want a second plugin to look after.
Comparison at a glance
| Criterion | Autoptimize | Asset CleanUp | WP Rocket |
|---|---|---|---|
| Price | €0 (completely free) | €0 basic / from $49/year Pro | $59/year |
| Per-page control | ❌ Global rules only | ✅ Outstanding, per post/page | Partly (exclusion lists, less granular) |
| CSS/JS minification | ✅ Very solid | ✅ (combined with aggregation) | ✅ Comprehensive |
| Unused CSS removal | ❌ (aggregation/defer only) | ✅ Pro version, manually per page | ✅ Automated (Remove Unused CSS) |
| Standalone or add-on to a cache plugin | Add-on, no caching of its own | Add-on, no caching of its own | Standalone all-in-one (cache + optimisation) |
| Learning curve | Shallow | Moderate to high (detailed work per page) | Very shallow |
Autoptimize — the lean standard for most sites
Strengths: Autoptimize does exactly what it was built for, and does it reliably: aggregate and minify CSS and JS, move scripts to the footer, inline critical CSS. The resource footprint is minimal, the plugin is completely free, and no Pro version is needed for the core function. For 80% of the sites I look after, the basic configuration combined with a cache plugin is entirely sufficient.
Weaknesses: No per-page control. If a single plugin loads unnecessary CSS site-wide, you cannot use Autoptimize to disable it selectively on individual pages — only aggregate and minify globally. Autoptimize also does not do genuine “remove unused CSS” in the sense of cutting unused selectors out of the CSS.
When to choose Autoptimize: As a standard add-on alongside any cache plugin, when you have no page-builder-specific CSS/JS bloat problems — classic blogs, corporate sites with a manageable number of plugins, anything where “aggregate and minify” already solves most of the problem.
Asset CleanUp — the surgical solution for page builder sites
Strengths: The unique selling point is unbeatable: you open a page on the front end, see a list of all loaded CSS and JS files with the plugin they belong to, and disable individual files directly on that page — no code, no risk for other pages. Especially on Elementor or Divi sites, where every installed widget plugin serves its CSS site-wide, this is the biggest lever I regularly find in audits. A contact form page does not need to load WooCommerce CSS, and a landing page without a slider does not need slider JS.
Weaknesses: The per-page maintenance is work — on larger sites with a hundred subpages this is not a five-minute setup but an iterative process over weeks. Anyone who carelessly disables the wrong file may in the worst case break the layout or a function on exactly that page. There is no automated “remove unused CSS” as in WP Rocket — control stays manual.
When to choose Asset CleanUp: Elementor or Divi sites with many plugins and visible CSS/JS bloat, and sites with recurring page types (landing pages, product pages) where the one-off maintenance work pays off across many similar pages.
Do you want to know which CSS on your site is actually needed — and which is just ballast? In my online course I show you how I work through a site page by page with Asset CleanUp without breaking anything. → To the online course
WP Rocket — the built-in solution for those already on board
Strengths: If you are using WP Rocket for caching anyway, you get CSS/JS optimisation without a second plugin, without a second update to keep an eye on, and without compatibility risk between two tools. Remove Unused CSS analyses each page individually and loads only the CSS actually used — automated, with no manual per-page work. Delay JavaScript Execution postpones script execution until the first user interaction and in practice often affects the PageSpeed score more than any other single measure.
Weaknesses: It costs money, and you are essentially paying for caching AND optimisation in one package — anyone who only needs optimisation is paying for features they do not use. Per-page control does exist (exclusion lists for particular URLs or scripts), but it is nowhere near as granular and clear as in Asset CleanUp.
When to choose WP Rocket: If you already use WP Rocket for caching, or intend to anyway, and do not want to manage a second plugin layer. For the details on WP Rocket's caching side, see my comparison WP Rocket vs Perfmatters vs LiteSpeed Cache.
Head to head: feature depth
| Feature | Autoptimize | Asset CleanUp Pro | WP Rocket |
|---|---|---|---|
| Aggregate & minify CSS | ✅ | ✅ | ✅ |
| Aggregate & minify JS | ✅ | ✅ | ✅ |
| Move scripts to the footer | ✅ | ✅ | ✅ |
| Inline critical CSS | ✅ (manual/power-up) | ❌ | ✅ (automated) |
| Delay JS execution | ❌ | ❌ | ✅ |
| Automatically remove unused CSS per page | ❌ | ❌ (manual deactivation only) | ✅ |
| Selectively disable CSS/JS per post/page | ❌ | ✅ Core feature | Limited |
| Google Fonts optimisation | ✅ | ✅ (basic) | ✅ |
| HTML minification | ✅ | ❌ | ✅ |
| Its own page caching | ❌ | ❌ | ✅ |
| Database cleanup | ❌ | ❌ | ✅ |
Prices compared (as of 2026)
- Autoptimize: completely free, no Pro version needed for the core function. Individual power-ups (e.g. for critical CSS) are available separately and optionally.
- Asset CleanUp: free tier with basic functions (test mode, simple deactivation). Pro version from around $49/year for one site, $79/year for three sites, $149/year for unlimited sites.
- WP Rocket: from $59/year for one site (single licence), with tiered licences for multiple sites — here you pay for the complete package of caching and optimisation, not just for the CSS/JS features.
Who is each option right for?
The solopreneur with a blog and a lean plugin stack: Autoptimize alongside any cache plugin (e.g. the free WP Super Cache or your host's own server cache). No reason to pay more when the problem is small.
The Elementor agency client with many widget plugins: Asset CleanUp Pro. This is exactly where the difference between “somehow optimised” and “genuinely lean” shows — the per-page control wins load time points that no other tool on this list reaches.
The existing WP Rocket customer who does not want a third plugin layer: WP Rocket. You already have Remove Unused CSS and Delay JavaScript Execution in the licence package — adding Autoptimize or Asset CleanUp on top would bring conflicts rather than extra benefit.
My conclusion
These three tools are not truly in competition with each other — they solve different stages of the same problem. Autoptimize is my standard recommendation as a free add-on to any cache plugin when the requirements are modest. I bring in Asset CleanUp specifically for page builder sites with visible CSS/JS bloat — the per-page control is worth the money if you are prepared to invest the maintenance work. I recommend WP Rocket if you want an all-in-one package anyway and do not want to manage a second plugin to look after. Do not mistake these three for interchangeable caching alternatives — Autoptimize and Asset CleanUp generally still need a separate caching plugin alongside them.
Frequently asked questions
Do I need this in addition to WP Rocket?
No, in most cases not. WP Rocket already brings minification, Delay JavaScript Execution and Remove Unused CSS. Adding Autoptimize or Asset CleanUp on top tends to result in duplicate aggregation and conflicts rather than genuine extra benefit. The one exception: if you need Asset CleanUp's granular per-page control because WP Rocket's exclusion lists are not precise enough — in which case test the combination carefully on a staging environment.
Can I use Autoptimize and Asset CleanUp at the same time?
Technically possible, but not advisable. Both intervene in the aggregation of CSS/JS and can slow each other down or cause layout errors. Pick one.
Does one of these tools replace a caching plugin?
No — except WP Rocket, which is a fully fledged caching plugin in its own right. Autoptimize and Asset CleanUp optimise assets but do not cache whole pages. Without a separate caching plugin (WP Rocket, LiteSpeed Cache or similar) you are missing a central performance building block. More on this in WP Rocket vs Perfmatters vs LiteSpeed Cache.
How much does Remove Unused CSS really deliver?
In my tests on Elementor sites, between 10 and 25 PageSpeed Insights points, depending on the starting point. On sites with few plugins the effect is smaller; on page builder sites with a lot of CSS ballast it is clearly noticeable.
Can I accidentally break things with Asset CleanUp?
Yes, that is the biggest risk of the manual approach. Test mode initially shows changes only to you before you make them live for all visitors — use that consistently, and check every page on the front end after a deactivation.
What about image optimisation — do these tools handle that too?
Autoptimize offers simple lazy loading and WebP/AVIF support, as does WP Rocket. For genuine image compression I recommend dedicated tools — see ShortPixel vs Optimole.
The takeaway
First check which caching plugin you are already using — that decides the direction. If WP Rocket is already running, use its built-in optimisation. If a different caching setup is in place and you see a lot of unnecessary CSS/JS ballast on page builder pages, Asset CleanUp is worth it. For everything in between, Autoptimize is the solid, free standard route. If you are not sure where your site actually stands, my online course is the direct route to a well-founded assessment instead of guesswork. → To the online course
You will find all my tool comparisons at a glance in the WordPress tool comparisons overview.
Image source for featured & inline images: illustrations created in-house in the pletzenauer design (no stock photos).
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