WordPress — Core Web Vitals
The distribution, not just the median
Each bar is the good / needs-work / poor split for WordPress. The marks where the whole fleet sits, so you can see who is ahead and who is behind.
What moves Core Web Vitals on WordPress
Field data findings across WordPress sites from our metric deep dives.
WordPress sites with an HTML <img> hero pass LCP 4 percentage points more often than sites with CSS background heroes.
Across WordPress sites, 55.4% reference the hero image in initial HTML (77% good LCP, 1.7s median), 39.7% use section background-image styles (73% good LCP, 1.8s median), and sites with <link rel="preload"> pass at 79% good LCP.
WordPress sites with all fonts on swap pass LCP 10 points more often than mixed-rule sites.
Across WordPress, 48.8% of @font-face rules use swap and 50% use auto or block. Sites with every font on swap record a 1.5s median LCP (82% good LCP) compared with 1.9s (72% good LCP) on mixed-rule sites.
65.3% of WordPress sites call no main-thread yielding API.
Across WordPress, 65.3% of sites run scripts without a yielding API, 32.1% call requestIdleCallback(), and 2.6% call scheduler.yield().
84.2% of WordPress sites emit conservative speculation rules (60% CWV pass vs 62% with none).
WordPress 6.8+ enables Speculative Loading in core with prefetch and conservative eagerness by default, configurable with the wp_speculation_rules_configuration filter. Across WordPress, 84.2% of sites emit conservative rules (60% passing all three Core Web Vitals) compared with 62% on sites with no inline rules.
84.8% of WordPress hero elements carry no priority hint (79% good LCP with highprio vs 75% with none).
WordPress 6.3+ adds fetchpriority="high" to the first detected content image during server rendering. Across WordPress, 10.7% of LCP elements carry fetchpriority="high" (79% good LCP, 1.6s median) and 84.8% carry no priority hint (75% good LCP, 1.8s median).
42.4% of WordPress sites paint LCP from a CSS background-image (77% good LCP on <img> vs 73%).
Across WordPress sites, 35.2% paint LCP from an HTML <img> element (77% good LCP, 1.7s median) and 42.4% paint LCP from a CSS background-image (73% good LCP, 1.8s median, 4 points apart).
94.5% of WordPress sites serve their LCP image from the same origin (75% good LCP).
Across WordPress sites, 94.5% serve the LCP image from the first-party document origin (75% good LCP) and 5.5% serve it from an external origin (73% good LCP).
84.5% of WordPress sites emit document prefetch speculation rules (60% CWV pass rate).
WordPress 6.8+ enables Speculative Loading in core with a conservative prefetch posture by default. Across WordPress, 84.5% of sites with speculation rules use prefetch (60% passing all three Core Web Vitals) and 0.6% use prerender.
50.2% of WordPress sites compress HTML with gzip (75% good LCP vs 80% with Brotli, 5 points apart).
Across WordPress sites, 50.2% serve gzip-compressed HTML (75% good LCP, 1.8s median), 31.4% serve Brotli-compressed HTML (80% good LCP, 1.7s median), and 12.3% send uncompressed HTML (74% good LCP).
86.0% of WordPress sites serve main HTML directly from the origin server without a detected CDN proxy.
Across WordPress sites, 86.0% serve main HTML directly from the origin server (76% good LCP, 1.7s median) and 8.4% proxy main HTML through Cloudflare (77% good LCP).
WordPress is the largest CMS cohort in the dataset at 60% all-three Core Web Vitals pass rate.
Across 64,146 audited WordPress sites, 60% pass all three Core Web Vitals (LCP, INP, and CLS) simultaneously.
2.9% of WordPress sites use CSS @import rules, passing LCP 8 points less often than @import-free sites.
WordPress recommends enqueueing parent and child theme stylesheets with wp_enqueue_style(). Across WordPress, 97.1% of sites have no CSS @import (76% good LCP, 1.7s median) and 2.9% contain @import rules (68% good LCP, 2.0s median).
33.0% of WordPress sites serve at least one uncompressed text response (72% vs 78% good LCP, 6 percentage points apart).
Across WordPress, 67.0% of sites compress every text resource (78% good LCP, 1.7s median) and 33.0% serve at least one uncompressed HTML, CSS, JS, JSON, or SVG response (72% good LCP, 1.9s median).
87.7% of WordPress sites emit ETag headers, while 12.3% omit them.
Across WordPress sites, 87.7% serve ETag headers on responses (76% good LCP, 1.8s median) and 12.3% serve responses without ETag headers (79% good LCP, 1.6s median).
98.8% of WordPress sites send Last-Modified headers on responses.
Across WordPress sites, 98.8% emit Last-Modified headers (76% good LCP, 1.7s median).
WordPress sites have eager below-the-fold images on 93% of sites and lazy above-the-fold images on 18.6%.
WordPress 6.3+ adds loading="lazy" to content images while omitting it on the first three images. Across 64,084 WordPress sites, 76% with eager above-the-fold images pass LCP compared with 72% when an above-the-fold image has loading="lazy".
WordPress generates srcset on 81% of sites, while 7.4% use <picture>.
WordPress core adds srcset and sizes to attachment images with wp_calculate_image_srcset(). Across WordPress, 80.9% of sites use srcset on <img> (75% good LCP) and 7.4% use <picture> (77% good LCP).
WordPress sets width and height on 92.2% of sites, while 74.4% also have unsized images.
WordPress core adds width and height attributes to media library images with wp_img_tag_add_width_and_height_attr(). Across WordPress, 92.2% of sites include explicitly sized images (77% good CLS) and 74.4% include at least one unsized <img> (77% good CLS).
WordPress 6.3+ emits fetchpriority="high" on 65.6% of sites (74% good LCP).
WordPress 6.3+ adds fetchpriority="high" to the first large content image with wp_get_loading_optimization_attributes(). Across 63,819 WordPress sites, 65.6% include fetchpriority="high" (74% good LCP) compared with 76% on sites with default priority.
19.3% of iframe-using WordPress sites lazy-load iframes, while 89.4% use default iframe loading.
WordPress 5.7+ adds loading="lazy" to iframes with wp_iframe_tag_add_loading_attr(). Across iframe-using WordPress sites, 19.3% use loading="lazy" (73% good LCP) and 89.4% use default iframe loading (74% good LCP).
62.8% of iframe-using WordPress sites set explicit iframe dimensions (75% good CLS).
Across iframe-using WordPress sites, 62.8% include explicit width and height attributes on iframes (75% good CLS) and 82.0% include unsized iframes (75% good CLS).
WordPress sites using CSS hints include will-change on 84.8% and content-visibility on 37.3%.
Across 52,075 WordPress sites using CSS hints, 84.8% use will-change, 67.5% use aspect-ratio, and 37.3% use content-visibility (100% good INP).
On WordPress sites with lab layout shifts, embed_grow sites pass field CLS at 56% vs 76% on font_text sites.
Across 45,487 WordPress sites with lab layout shifts, 78.5% record element box growth (73% good field CLS), 24.1% record web font reflow (76% good CLS), and 0.7% record embed_grow (56% good CLS).
WordPress sites with downward layout shifts (49.7%) pass field CLS at 71% vs 74% for lateral shifts.
Across 45,466 shifting WordPress sites, 83.2% record horizontal shifts (74% good field CLS) and 49.7% record downward vertical shifts (71% good CLS).
WordPress sites fetch subresources over HTTP/2 on 96.9%, HTTP/3 on 78.2%, and HTTP/1.1 on 62.1%.
Across 64,146 WordPress sites, 96.9% fetch subresources over HTTP/2 (76% good LCP), 78.2% over HTTP/3, and 62.1% include at least one HTTP/1.1 request (74% good LCP).
15.9% of WordPress sites serve Cache-Control: immutable assets, while 80.2% use long TTLs.
WordPress core appends a ?ver= query string to enqueued scripts and styles with wp_enqueue_script(). Across WordPress, 80.2% of sites serve long-TTL static files and 15.9% emit Cache-Control: immutable.
WordPress sites with analytics run GA4 on 94.5% and Universal Analytics tags on 76.9%.
Across 39,081 analytics-using WordPress sites, 94.5% load Google Analytics 4 (100% good INP), 76.9% include Universal Analytics script references, and 8.0% run Matomo (100% good INP).
Ad-supported WordPress sites pass all three CWV at 54% with AdSense (94.0%) and 53% with Taboola.
Across 5,185 ad-supported WordPress sites, 94.0% run Google AdSense (54% passing all three CWV), 15.9% run Google Publisher Tag (53%), and 5.4% run Prebid.js (57%), compared with 60% across all ad-using WordPress sites.
WordPress sites with a tag manager use GTM on 93.9% (100% good INP) and Matomo on 7.3%.
Across 35,341 tag-manager-using WordPress sites, 93.9% load Google Tag Manager (100% good INP) and 7.3% load Matomo Tag Manager (100% good INP), compared with 100% across the cohort.
WordPress sites load external analytics on 60.9% and third-party font services on 58.8% (57% CWV pass).
Across 64,146 WordPress sites, 96.5% load a JS library, 60.9% load analytics (59% passing all three CWV), 58.8% load external font services (57%), and 57.7% use a CDN (59%).
WordPress pages with 1,500+ DOM elements (15.9%) pass field INP at 99% vs 100% at 400 to 799 nodes.
Across 64,146 WordPress sites, 37.4% have between 400 and 799 DOM nodes (100% good INP, 45ms median) and 15.9% exceed 1,500 nodes (99% good INP, 56ms median).
WordPress pages over 75 KB HTML (10.9%) pass LCP at 65% vs 84% under 14 KB.
Across 64,146 WordPress sites, 11.8% ship HTML under 14 KB (84% good LCP, 1.5s median), 39.6% ship 14 to 30 KB (84% good LCP), 37.8% ship 30 to 75 KB (71% good LCP), and 10.9% exceed 75 KB (65% good LCP).
88.3% of WordPress sites preload zero fonts (77% good LCP), while 6.6% preload 1 to 2 fonts.
Across 64,146 WordPress sites, 88.3% emit no font preload links (77% good LCP), 6.6% preload 1 to 2 fonts (70% good LCP), and 5% preload 3 or more font files.
WordPress pages embedding 4+ iframes (9.1%) pass field CLS at 73% vs 80% with 0 iframes.
Across 64,146 WordPress sites, 53.5% embed 0 iframes (80% good CLS), 16.2% embed 1 iframe (76%), 21.2% embed 2 to 3 (77%), and 9.1% embed 4+ iframes (73% good CLS).
WordPress pages with multi-shift lab CLS (18.2%) pass field CLS at 69% vs 79% for a single shift.
Across 45,487 WordPress sites with non-zero lab CLS, 57.8% have 95%+ of their CLS in a single shift (79% good field CLS), 24.0% sit at 65% to 94% (71%), and 18.2% have multiple shifts (69% good CLS).
WordPress pages with 6+ lab layout shifts (14.8%) pass field CLS at 66% vs 84% with 0 shifts (18 points apart).
Across 64,142 WordPress sites, 25.8% record 0 lab shifts (84% good CLS), 43.9% record 1 to 2 shifts (81%), 15.5% record 3 to 5 shifts (69%), and 14.8% record 6+ shifts (66% good CLS).
Shifting WordPress sites with a largest shift over 0.25 (12.5%) pass field CLS at 52% vs 86% under 0.01 (34 points apart).
Across 47,581 WordPress sites with non-zero lab CLS, 37.8% have a largest shift under 0.01 (86% good CLS), 35.3% sit at 0.01 to 0.10 (78%), 14.3% sit at 0.10 to 0.25 (66%), and 12.5% exceed 0.25 (52% good CLS).
WordPress sites connecting to 15+ domains (10.5%) pass all three CWV at 53% vs 70% at 1 to 3 domains (17 points apart).
Across 64,146 WordPress sites, 21.9% connect to 1 to 3 domains (70% passing all three CWV), 35.3% use 4 to 7 domains (63%), 32.3% use 8 to 14 domains (60%), and 10.5% connect to 15+ domains (53%).
35.9% of WordPress sites mark under 20% of resources cacheable (73% good LCP vs 76% at 80%+).
Across 64,146 WordPress sites, 38.7% mark 80%+ of subresources as cacheable (76% good LCP), 17.3% cache 50% to 79% (78% good LCP), and 35.9% cache under 20% (73% good LCP).
WordPress sites with 9+ third-party providers (12.5%) pass all three CWV at 55% vs 70% with 0 to 1 providers.
Across 64,146 WordPress sites, 24.4% load 0 to 1 external providers (70% passing all three CWV), 28.3% load 2 to 4 (64%), 34.8% load 5 to 8 (59%), and 12.5% load 9+ providers (55%).
86.7% of WordPress sites serve PNG images, 85.8% serve JPEG, and 39.0% serve WebP.
WordPress 6.5 added native AVIF upload support alongside existing WebP, JPEG, and PNG support. Across 64,082 WordPress sites, 86.7% include PNG files (75% good LCP), 85.8% include JPEGs (75% good LCP), and 39.0% include WebP (74% good LCP).
89.2% of WordPress sites load render-blocking synchronous scripts (75% good LCP).
WordPress 6.3+ supports registering scripts with defer and async strategies in wp_register_script() and wp_enqueue_script(). Across WordPress, 89.2% of sites execute render-blocking scripts (75% good LCP, 1.8s median) and 14.1% use ES modules (76% good LCP).
77.6% of WordPress sites execute third-party scripts (100% good INP vs 100% on first-party).
Across 64,131 WordPress sites, 100.0% execute first-party scripts (100% good INP, 48ms median) and 77.6% also load cross-origin third-party scripts (100% good INP, 49ms median).
35.7% of WordPress sites place <link rel="stylesheet"> tags inside <body> (68% vs 76% good LCP, 8 points apart).
WordPress 5.8+ provides the should_load_separate_core_block_assets filter to enqueue styles only for used blocks in <head>. Across WordPress, 98.9% of sites load blocking <head> stylesheets (76% good LCP, 1.7s median) and 35.7% include <link rel="stylesheet"> tags inside <body> (68% good LCP, 2.0s median).
59.7% of WordPress sites load third-party CSS (74% good LCP vs 76% on first-party CSS).
Across 64,140 WordPress sites, 100.0% load first-party stylesheets (76% good LCP, 1.7s median) and 59.7% load external third-party stylesheets (74% good LCP, 1.8s median).
40.0% of WordPress sites inject stylesheets from JavaScript (73% vs 76% good LCP, 3 points apart).
Across 64,140 WordPress sites, 97.4% load CSS from the HTML parser (76% good LCP, 1.8s median) and 40.0% inject stylesheets from JavaScript (73% good LCP, 1.8s median).
36.6% of WordPress sites download WOFF and 18.3% download TTF (72% good LCP vs 75% for WOFF2).
Across 62,323 font-using WordPress sites, 94.7% serve WOFF2 (75% good LCP), 36.6% download WOFF (71% good LCP), and 18.3% download TrueType TTF files (72% good LCP, 1.9s median).
87.1% of media-using WordPress sites stream video from their own origin (74% good LCP, 1.8s median).
Across 7,788 WordPress sites with <video> or <audio> elements, 87.1% serve media files from their own origin (74% good LCP) and 14.6% serve media from an external CDN (72% good LCP).
75.1% of WordPress sites run recurring setInterval() timers, while 2.6% call scheduler.yield().
Across 64,016 WordPress sites, 77.2% call requestAnimationFrame() (100% good INP), 75.1% call setInterval() (100% good INP), and 2.6% call scheduler.yield().
On WordPress sites with Long Animation Frames, 40.7% record timer/rAF callbacks and 36.1% record event listeners.
Across 34,390 WordPress sites recording LoAF entries, 40.7% record long frames in setTimeout/requestAnimationFrame callbacks (100% good INP), 38.6% during classic <script> evaluation (100%), and 36.1% in DOM event listeners (99%).
WordPress sites load scripts on 100.0%, images on 99.9%, CSS on 99.2%, and web fonts on 97.2%.
Across 64,146 WordPress sites, 100.0% load external JavaScript, 99.9% load images, 99.2% load CSS stylesheets, and 97.2% download web fonts (76% good LCP, 1.8s median).
99.8% of WordPress sites fetch subresources from origin/custom hosts, 42.1% use Cloudflare, and 19.2% use CloudFront.
Across 64,146 WordPress sites, 99.8% serve subresources from origin or custom hosts (76% good LCP), 42.1% use Cloudflare (74% good LCP), 19.2% use CloudFront (72%), and 10.6% use Fastly (74%).
WordPress sites shipping over 3 MB of images pass LCP 11 points less often than sites under 350 KB.
Across WordPress sites, 35% transfer 1 to 3 MB of images and 31% exceed 3 MB. Sites under 350 KB pass LCP at 83% (1.5s median) compared with 72% (1.9s median) above 3 MB.
WordPress sites over 160 KB of CSS pass LCP 25 points less often than sites under 40 KB.
Across WordPress sites, 36% ship over 160 KB of stylesheets (64% LCP pass rate, 2.1s median) and 13% ship under 40 KB (89% pass rate, 1.3s median).
38% of WordPress sites load over 600 KB of unused CSS (66% vs 90% good LCP under 140 KB).
Across WordPress sites, 38% have over 600 KB of unused CSS (66% good LCP, 2.0s median) compared with 90% (1.3s median) under 140 KB.
32% of WordPress sites load 7+ font files, passing LCP 14 points less often than sites with 1 to 3 fonts.
Across WordPress sites, 32% request 7 or more web font files (69% good LCP, 1.9s median) compared with 83% (1.5s median) on sites with 1 to 3 fonts.
WordPress sites setting 6+ cookies pass LCP 18 points less often than sites with 0 cookies.
Across WordPress sites, 28% set zero cookies on initial load (86% good LCP, 1.5s median) and 35% set 6 or more cookies (68% good LCP, 2.0s median).
WordPress sites over 1,500ms lab LCP pass field LCP at 57% vs 89% under 300ms.
Across WordPress sites, 32% take over 1,500ms to paint in unthrottled lab conditions (57% field LCP pass rate, 2.3s median) compared with 89% (1.3s median) on the 16% painting under 300ms.
WordPress sites taking over 1,500ms to reach DOMComplete pass LCP 29 points less often than sites under 350ms.
Across WordPress sites, 34% take over 1,500ms to reach DOMComplete in the lab (59% field LCP pass rate, 2.2s median) compared with 88% (1.2s median) on the 13% finishing under 350ms.
Server TTFB is the largest LCP phase on 84% of WordPress sites (74% good LCP vs 83% when load delay leads).
Across WordPress sites, TTFB is the largest LCP sub-part on 84% (74% LCP pass rate, 1.8s median) and load delay is the largest sub-part on 9% (83% pass rate, 1.5s median).
60% of WordPress sites exceed 2.5 MB of total page weight (70% good LCP over 5 MB vs 89% under 1.2 MB, 19 points apart).
Across WordPress sites, 31% transfer 2.5 to 5 MB, 29% exceed 5 MB (70% LCP pass rate, 1.9s median), and 13% transfer under 1.2 MB (89% pass rate, 1.3s median).
CMS standings
210,902 crawled sites (69,745 with desktop Chrome field data), representing millions of real page loads, October 2026 edition. How we measured.