Smush
by WPMU DEV
Image optimization for WordPress. Lossless compression, lazy loading, WebP conversion, automatic.
- Lighthouse
- 95 / 100 Tested June 1, 2026
- Accessibility
- WCAG AA
- Open CVEs
- 0
- Last release
- May 15, 2026 v3.18.1
- WP.org rating
- 4.8
Smush is WPMU DEV's image optimization plugin, one of the longest-running in the WordPress ecosystem (launched 2011). Lossless compression of uploaded images, lazy loading, WebP conversion, bulk optimization. Free version handles most personal sites; Smush Pro adds bulk processing, larger file size limits, and CDN delivery.
Pros
- Long-running plugin with proven reliability
- Automatic optimization on upload (set and forget)
- Strong WPMU DEV ecosystem integration if you use other WPMU DEV products
- Free version is generous for most personal sites
Cons
- Pro tier required for bulk processing past 50 images at a time
- Performance gains depend heavily on the existing image library state
- Alternative plugins (ShortPixel, Imagify) may compress more aggressively at the same quality settings
Pick Smush when you want a long-running, well-tested image optimization plugin and you appreciate the WPMU DEV ecosystem integration.
Avoid for very large image libraries (10K+ images) where Pro becomes essential, or for sites where ShortPixel's more aggressive compression is preferred.
Frequently asked questions
- Is Smush free?
- Yes for the base tier (lossless compression, lazy loading, basic WebP). Smush Pro ($12+/month) adds bulk processing beyond 50 images, larger file size limits, CDN delivery, and Pro-tier optimization algorithms.
- Smush vs ShortPixel?
- ShortPixel typically compresses more aggressively at the same quality level. Smush has the larger install base and tighter WPMU DEV ecosystem integration. Performance-sensitive teams often pick ShortPixel; WPMU DEV product family users stick with Smush.
- Does Smush convert images to WebP?
- Yes, in both free and Pro tiers. WebP serving is automatic once enabled; the plugin handles fallback to original formats for browsers that don't support WebP.
- Is Smush part of WPMU DEV?
- Yes. WPMU DEV (Australia-based, founded 2004) owns Smush alongside Hummingbird, Defender, Forminator, and SmartCrawl. Subscription business model bundles the entire plugin portfolio.
Recent releases
- v3.18.1 May 15, 2026
WebP delivery improvements
- v3.18.0 April 8, 2026
New: AVIF format support in Pro
- v3.17.4 February 22, 2026
Patch release
- v3.17.3 January 18, 2026
Maintenance release
- v3.17.2 November 15, 2025
WordPress 6.7 compatibility
- v3.17.1 September 22, 2025
Lazy loading edge case fix
-
WP Rocket
Premium caching plugin. Page cache, file optimization, lazy loading, database cleanup, no free version.
-
LiteSpeed Cache
Free caching plugin from LiteSpeed Technologies. Top-tier performance when paired with LiteSpeed-hosted environments.
-
AI Engine
Most-featured AI plugin for WordPress. Chatbots, content generation, image generation, MCP server endpoints, multi-provider.
-
All-In-One Security (AIOS)
The most-installed free WordPress firewall and hardening plugin. Genuinely capable free tier from the UpdraftPlus team.
Performance testing
Tested on Kinsta Starter (Google Cloud C3D, Iowa). Configuration: Smush default settings with auto-optimization, Twenty Twenty-Four theme, sample media library of 50 images, mobile, 4G simulated, cold cache. 5 runs, median reported. Raw Lighthouse JSON downloadable on request.
Vulnerability tracking
Open and recently closed CVE counts pulled from Patchstack and Wordfence Intelligence on every build. Last disclosure date reflects the most recent public CVE for this plugin, not necessarily the most recent vendor patch.