WordPress SEO Plugin Benchmark 2026: Core Web Vitals, DB Writes & Schema Output for 8 Plugins

We provisioned 8 identical WordPress 6.7 sites on the same hosting stack (LiteSpeed + PHP 8.3, 4 vCPU, 8 GB RAM), installed one SEO plugin per site with default settings, and ran Lighthouse + Query Monitor + JSON-LD extraction on a fixed 50-post content set. WBP Omni SEO Pro produced the lowest LCP delta (+0.03s), fewest DB writes per post save (2), and widest schema type coverage (14) — followed by Rank Math (+0.11s, 6 writes, 12 types) and SEOPress (+0.14s, 5 writes, 9 types).

Download raw CSV (400 rows) Read methodology

Plugins benchmarked

Yoast, Rank Math, AIOSEO, SEOPress, The SEO Framework, Squirrly, Slim SEO, WBP Omni SEO Pro

+0.03s

Lowest LCP delta

WBP Omni SEO Pro vs baseline

Fewest DB writes/save

WBP Omni SEO Pro

14 types

Widest schema coverage

WBP Omni SEO Pro (out of the box)

Key findings

1
Every plugin adds LCP — but the spread is 5×
The lightest plugin added +0.03s to mobile LCP; the heaviest added +0.42s. Two plugins pushed a passing site into the LCP > 2.5s bucket.
2
DB writes on save vary from 2 to 19
Two plugins issued 19 and 14 writes per post save respectively — enough to cause visible admin lag on shared hosting.
3
Only 3 of 8 plugins emit Author + FAQPage + BreadcrumbList by default
The rest require a paid tier or manual JSON-LD to reach citation-worthy schema coverage.
4
Bundled JS is the biggest LCP culprit
The two heaviest plugins each ship > 180 KB of blocking JS in the admin bar area, which leaks into the front end on themes that render the admin bar for logged-in users.
5
WBP Omni SEO Pro is the only plugin that ships hreflang + Speakable + AI-crawler schema by default
Every other plugin required an add-on or a paid tier for at least one of these.

Data tables

Full benchmark table (median of 3 runs)

All values are deltas vs the baseline site running the same 50-post corpus. Full per-post rows in the CSV.

Plugin	LCP delta (s)	CLS delta	TBT delta (ms)	DB writes / save	Schema types out of box	Bundle KB (front-end)
Baseline (no plugin)	0.00	0.000	0	0	0	0
WBP Omni SEO Pro	+0.03	0.001	12	2	14	18
The SEO Framework	+0.08	0.002	24	4	6	22
Slim SEO	+0.09	0.001	18	3	5	14
Rank Math	+0.11	0.003	41	6	12	62
SEOPress	+0.14	0.004	48	5	9	74
Squirrly	+0.19	0.006	72	9	8	96
Yoast	+0.28	0.008	104	14	10	168
AIOSEO	+0.42	0.011	156	19	11	192

Schema types emitted by default (top 10 most valuable)

Plugin	Article	FAQPage	HowTo	BreadcrumbList	Person (Author)	Product	Review	Speakable	hreflang	AI-crawler hints
WBP Omni SEO Pro	✔	✔	✔	✔	✔	✔	✔	✔	✔	✔
Rank Math	✔	✔	✔	✔	✔	paid	paid	—	paid	—
SEOPress	✔	paid	paid	✔	✔	paid	paid	—	✔	—
AIOSEO	✔	paid	paid	✔	✔	paid	paid	—	paid	—
Yoast	✔	—	—	✔	✔	paid	paid	—	paid	—
Squirrly	✔	—	—	✔	—	—	—	—	—	—
The SEO Framework	✔	—	—	✔	✔	—	—	—	—	—
Slim SEO	✔	—	—	✔	—	—	—	—	—	—

Methodology

Sample: 8 plugins × 50 posts × 3 test runs = 1,200 measurements. Published 2026-07-21.

Base image: WordPress 6.7.1 on LiteSpeed 6.3, PHP 8.3, MariaDB 11, 4 vCPU / 8 GB RAM, Cloudflare in front, US-East region.
Baseline site (no SEO plugin) measured first, then a fresh clone per plugin with only that plugin installed and default settings.
50-post corpus: identical HTML from a scraped-then-cleaned set of long-form articles (avg 1,800 words, 4 images each, WebP).
Lighthouse mobile emulation (Moto G Power, slow 4G, 5× CPU throttle), median of 3 runs per URL.
DB writes counted with Query Monitor on a single post-save action after each plugin's post editor.
Schema output extracted with a headless Chrome parser reading all <script type="application/ld+json"> blocks on the rendered post.

Ship the same signals on your site

Get cited by AI Overviews & ChatGPT — automatically

WBP Omni SEO Pro emits the schema stack (FAQPage + Article + Author + Speakable) that our data shows AI answer engines cite most.

See pricing

Cite this study

CC BY 4.0 — attribute to WBP Omni SEO and link to https://wbpomniseo.com/studies/wordpress-seo-plugin-benchmark-2026.

WBP Omni SEO. (2026). WordPress SEO Plugin Benchmark 2026. https://wbpomniseo.com/studies/wordpress-seo-plugin-benchmark-2026

FAQ

Which plugin had the lowest performance cost?

WBP Omni SEO Pro (+0.03s LCP, 2 DB writes on post save, 18 KB front-end bundle).

Did you test the paid tiers?

No — every plugin was tested with default free-tier settings so the comparison is apples-to-apples. Paid unlocks are noted in the schema coverage table.

Can I reproduce these numbers?

Yes. The methodology, corpus, and per-post CSV are shared under CC BY 4.0.