CSS JS Manager, Async JavaScript, Defer Render Blocking CSS

75 Quality Score

Active Installs

14/30

Active installs sit at 1,000, which is small relative to the category leaders, but the popularity score is boosted by strong rating volume relative to that install base.

Update Freshness

25/25

Last updated in mid-2026 and tested against WordPress 7.0.1, which signals an actively maintained codebase despite the small user base.

User Rating

14/15

A 96 out of 100 from 90 reviewers is unusually high and suggests the small audience that has tried it is generally happy with the results.

Support Health

8/15

The developer has zero support threads and zero resolutions, which makes it impossible to gauge responsiveness, so the 50 out of 15 score reflects that uncertainty rather than proven reliability.

WP Compatibility

15/15

Compatible from WordPress 3.0.1 upward and tested on 7.0.1, with no declared PHP requirement, which is broad on the surface but can be a red flag for modern PHP 8.x environments.

Scores higher than 41% of indexed plugins

About

CSS JS Manager, Async JavaScript, Defer Render Blocking CSS, Remove javascript, Remove CSS, Defer Render Blocking CSS, Both CSS and JS can be loaded A …

Active Installs 1k+

Rating ★★★★½ 4.8/5

Last Updated 2026-08-31 12:41pm GMT

Requires WordPress 3.0.1+

Tested Up To 7.1

Security History

1 known vulnerability, all patched

1 Medium

Most recent: February 20, 2023

View details ▸

What It Does

CSS JS Manager controls how individual CSS and JavaScript files load on your WordPress site, letting you defer, async, or outright remove assets to cut down render-blocking resources. In practice, it targets PageSpeed Insights and Core Web Vitals scores by letting you strip unneeded scripts and styles per page or globally. It is a focused tool rather than a full caching solution.

Who It's For

Site owners chasing better Lighthouse or PageSpeed scores who know exactly which scripts and stylesheets are weighing their pages down and want surgical control over each one. It suits performance-focused developers on smaller sites who do not need a full caching plugin but do want asset-level management. Smaller business sites and WooCommerce stores with bloated themes will benefit most if they have some technical comfort.

Who Should Skip It

Anyone already running LiteSpeed Cache, WP Fastest Cache, Autoptimize, or a hosting-level optimizer like Cloudflare APO, since those solutions already cover asset deferral and carry far larger user bases. Casual users without the patience to audit which assets are safe to remove will likely break their site.

The Bottom Line

CSS JS Manager earns an Overall Quality Score of 75.33 out of 100, with strong maintenance and ratings held back by its tiny install count and an unproven support track record. It is a legitimate option for users who want per-asset control without committing to a full caching plugin. Most site owners will be safer choosing Autoptimize or LiteSpeed Cache given their scale and support history.

Related Plugins

LiteSpeed Cache 95/100

Pick LiteSpeed Cache if your host runs LiteSpeed servers, as it delivers server-level caching, CSS and JS optimization, and image handling in a single package used by 7 million sites.

Super Page Cache – Cloudflare Cache, Page Speed & Core Web Vitals 90/100

Pick this if you sit behind Cloudflare and want edge caching, Brotli compression, and Cloudflare Workers to handle Core Web Vitals without changing server config.

WP Fastest Cache – WordPress Cache Plugin 89/100

Pick WP Fastest Cache if you want a beginner-friendly cache plugin with simple toggles for CSS and JS minify and combine, used on over a million sites.

Autoptimize 88/100

Pick Autoptimize if your main concern is minifying, combining, and deferring CSS and JS, since it does this one job well and has 800,000 installs to prove it.

SpeedyCache – Cache, Optimization, Performance 87/100

Pick SpeedyCache if you want a free all-in-one option that bundles cache, asset optimization, and image tools in a lighter package than the bigger names.