LiteSpeed vs Nginx for WordPress: 3 months of production benchmarks

TL;DR

Ran LiteSpeed Enterprise (LSWS) and Nginx side-by-side on identical VPS instances for 3 months, hosting the same 12 WordPress sites on each. LiteSpeed came out 33-45% faster on TTFB and moved 10/12 sites to a 90+ mobile PageSpeed score vs. 3/12 on Nginx. But ~80% of that advantage doesn't come from LSWS itself - it comes from the LSCache plugin, which also works with OpenLiteSpeed (free). If you're deciding today: OpenLiteSpeed + LSCache is the pragmatic answer for most WordPress workloads.

The setup

Two identical VPS instances at the same Israeli data center:

• Server A: LiteSpeed Enterprise 6.2 + LSCache 5.7 + PHP 8.2 (LSAPI) + CloudLinux
• Server B: Nginx 1.24 + PHP 8.2 FPM + FastCGI cache + Redis object cache

Spec on each: 4 vCPU, 8 GB RAM, 100 GB NVMe, Ubuntu 22.04.

12 WordPress sites migrated to each (same versions, same plugin stack):

• 4 brochure sites (~50 pages, empty WooCommerce)
• 4 WooCommerce stores (500-2000 products)
• 4 Elementor blogs (500+ posts)

Load simulated with k6, 100 concurrent users, 30-min runs, realistic paths: home → category → product → cart → checkout.

Results - TTFB

Results - RPS under load

The gap widens with deeper PHP call trees. WooCommerce with a big catalog is nearly 2× faster on LSWS. Reason: LSAPI keeps a persistent worker pool that avoids PHP-FPM's cold-start overhead on complex requests.

Results - PageSpeed Insights (mobile)

Averages across all 12 sites, both stacks with the same image + Critical-CSS pipeline:

LiteSpeed moved 10/12 sites to 90+. Nginx got 3/12 there.

The plot twist

Three months in, I did one more test: installed OpenLiteSpeed (free, MIT license) + LSCache on Server B, in place of Nginx. Same 12 sites.

~80% of LiteSpeed Enterprise's advantage came from the cache plugin, not the server.

LSCache does four things no other WordPress cache plugin does at the same level:

• QUIC.cloud CDN, free tier (built into the plugin)
• Image optimization + WebP conversion in-process
• Automatic Critical CSS generation
• ESI edge-side includes - cache the shell of a page while keeping dynamic bits fresh (mini-carts, logged-in nav)

Recommended config

wp-config.php:

define('WP_CACHE', true);
define('WP_DEBUG', false);
define('WP_REDIS_HOST', '127.0.0.1');
define('WP_REDIS_PORT', 6379);
define('WP_REDIS_DATABASE', 0);
define('WP_POST_REVISIONS', 5);
define('AUTOSAVE_INTERVAL', 300);

Critical LSCache settings (Dashboard → LiteSpeed Cache):

• Cache → General → Enable Cache: On
• Cache → General → Cache Logged-in Users: Off (important)
• Cache → Object → Object Cache: Redis
• Cache → ESI → Enable ESI: On
• CDN → QUIC.cloud CDN: On
• Page Optimization → CSS: Combine + Minify + UCSS
• Page Optimization → JS: Combine + Defer
• Page Optimization → Images: Guest Optimization + Lazy Load
• Page Optimization → HTML: Minify + DNS Prefetch

When Nginx still wins

• API-only WordPress backends (headless) - Nginx + FPM has a tighter footprint for pure JSON responses.
• Truly static traffic - landing pages, marketing sites with no dynamic content. Nginx + static file cache is unbeatable there.
• Team that only knows Nginx - LSWS/OLS learning curve isn't worth it for a single box.

Eight-point WordPress performance checklist

1. curl -o /dev/null -s -w "%{time_starttransfer}\n" https://yoursite.com/ → TTFB under 200 ms
2. PageSpeed Insights on home + 3 product pages → LCP under 2.5 s
3. GTmetrix waterfall → cache HIT on every static asset
4. X-LiteSpeed-Cache: hit header on repeat requests (or equivalent for your cache)
5. Search Console → Core Web Vitals → 90%+ URLs "Good"
6. wp cli plugin list --status=active → under 25 active plugins
7. wp-admin → Site Health → no "Critical" issues
8. Redis object cache active - check "Cache Statistics" in your cache plugin

Bottom line

For WordPress in 2026:

• On a shared host: LiteSpeed Enterprise + LSCache is the strongest option. Pay the license, forget about tuning.
• On your own VPS: OpenLiteSpeed + LSCache gets you 90% of the way there for free.
• Nginx: still the right call for API-only or ultra-static workloads, or if your team lives and breathes it.

Two days of proper LSCache config usually beats switching hosts.

I run Linux Hosting, an Israeli hosting provider running LiteSpeed Enterprise + LSCache across every plan. Comments and pushback welcome - this was measured on a real customer fleet, but every setup is different and I'd love to see other benchmarks.