Before we get into the details. Here’s the plain English version
Most WordPress site owners don’t need a complicated SEO plugin. They need one that works.
They need their page titles to show up correctly in Google. They need a sitemap so search engines can find their content. They need to control what shows up when someone shares a page on social media. Maybe a redirect here and there when something moves.
That’s it. That’s the whole list for most people.
The problem isn’t that popular SEO plugins are bad at those things. It’s that over time they’ve grown into something much bigger — with features most users will never touch, settings that take a degree to understand, and update cycles that feel like they never stop. All of that has a cost. It adds weight to your WordPress admin, and for a lot of sites that cost is real and measurable.
Mantis SEO started as our answer to that. Give people exactly what they need, nothing they don’t, and make sure it runs as lightly as possible.
The rest of this post gets into what we found when we actually measured it.
This started with a support company problem
I run WP Mantis, a WordPress support and maintenance company. Our job is to keep client sites updated, secure, and running the best it can.
About 90% of our clients use Yoast SEO. That’s not a surprise, or at least it shouldn’t be; it’s the most widely installed SEO plugin on WordPress, and it’s what most people default to. For years, it wasn’t something I thought much about. You install it, configure it, and move on.
But over the last couple of months, the update cadence for Yoast, both free and Pro, has picked up. We’re talking what feels like weekly updates at this point.
That might not sound like a big deal if you’re running one site. When your job is keeping plugins updated across dozens of client sites, it adds up fast. Each update means review time, testing time, and the background question: “What changed and what might break this time?”
That frustration is what made me look more closely at what Yoast actually is.
What I found when I looked under the hood
I conducted a code audit before running a single performance test. I wanted to understand what we were actually dealing with.
Here’s what Yoast looks like in 2026:
- 1,227 PHP files
- 350+ dependency injection services
- Two codebases running in parallel — a legacy system and a modern namespaced system that haven’t been fully merged
- 60+ conditional integrations with third-party plugins and WordPress features
This isn’t a knock on Yoast.
This is what happens when a plugin has been developed for many years, by a large team, with an expanding feature set and a freemium business model that requires constant development.
Large codebases are a natural result of that.
But here’s the thing. Most of my clients are small businesses running straightforward WordPress sites.
An accountant. A service company. A blogger. And so on.
They need their page titles to show up correctly in Google. They need a sitemap. They need to control what shows up when someone shares their page on Facebook. They don’t need 1,227 PHP files to get there.
That realization is what started the testing.
Making sure it wasn’t just us
Before I built anything, I wanted to make sure this wasn’t an isolated problem in our environment. So I went looking for what other people were experiencing.
What I found was consistent, and it’s been going on for years.
On WordPress.org, a reviewer in April 2025 called Yoast “the most bloated and heavy plugin I’ve interacted with yet,” saying it adds several seconds to backend page load times on pages that have nothing to do with SEO. They switched to something else. Read the review →
A January 2024 review titled “Stop the Bloat” described it as having become “bloated, cluttered, noisy, distracting, and constantly trying to upsell”, and made a great point: the fact that someone built a separate plugin called Hide SEO Bloat, specifically to clean up what Yoast adds to your dashboard, says everything. Read the review →
A developer managing 30 sites described the free version as “extremely bloated and often unintuitive,” saying it “hijacks a lot of space in your WP administration environment.” Read the review →
In Yoast’s own GitHub, issue #15341 documents a database query introduced in version 14.2 that was taking around 80 seconds to run on every dashboard load, including pages with no SEO relevance at all. Read the issue →
Issue #16713 documents post saving becoming extremely slow with Yoast active, traced to the link builder running on every autosave. Read the issue →
On the GeneratePress community forums, multiple users described installing Yoast and watching their admin slow to a near halt, then everything returning to normal the moment they removed it. Read the thread →
On WordPress.com support forums, a June 2025 thread describes Yoast taking a very long time to load on every page, significantly slowing down the editing process. Read the thread →
A developer who switched to a different plugin wrote a post titled “Yoast SEO you big bloat” after getting fed up with both the admin slowdowns and the constant upsell messaging. Read the post →
A WordPress developer published a guide specifically about removing Yoast’s bloat, concluding that the plugin has “hijacked WP in so many ways of late.” Read the post →
This wasn’t isolated. It wasn’t our environment. It was a real and widespread pattern. That was enough for me to move forward.
The test
We set up a controlled environment.
The same WordPress install, same hosting, same theme, same active plugins, same post open in the editor. The only thing we changed was which SEO plugin was active. We tested with Yoast, with Mantis SEO, and with no SEO plugin at all as a clean baseline.
Then we duplicated the test across several client sites to make sure we weren’t seeing a fluke. The results held.
We used Query Monitor to measure everything.
Page generation time, memory usage, database queries, and query execution time.
If you’re not familiar with it, Query Monitor is a free plugin that logs exactly what WordPress is doing under the hood on every page load. It’s one of the most useful diagnostic tools in the WordPress developer toolkit.
All primary measurements were taken on the post editor, the page that most WordPress users spend the most time in.
Here’s what we found
| What we measured | Mantis SEO | Yoast SEO | No SEO plugin |
|---|---|---|---|
| Page generation time | 0.7216s | 0.8088s | 0.7504s |
| Peak memory usage | 104.0 MB | 121.5 MB | 103.1 MB |
| Database queries | 253 | 264 | 252 |
| DB query execution time | 0.0539s | 0.0626s | 0.0545s |
| Memory added above baseline | +0.9 MB | +18.4 MB | — |
A few numbers worth calling out:
- Mantis SEO loads the post editor 10.7% faster than Yoast.
- Yoast uses 17.5 MB more memory on the same page.
- Mantis adds one database query above the no-plugin baseline, and Yoast adds twelve.
- In terms of raw overhead, Mantis adds only 0.9 MB to what WordPress uses without any SEO plugin. Yoast adds 18.4 MB, twenty times more.
That last one is the number that stuck with me. Running Mantis SEO on a site is nearly indistinguishable from running no SEO plugin at all. You’re getting full SEO coverage for essentially zero performance cost.
What Mantis SEO actually does
I want to be clear about what we built. Mantis SEO is not trying to do everything Yoast does. Most of my clients don’t need everything Yoast does.
In fact, that was the whole design principle.
I started by looking at what our clients actually use Yoast for. Almost universally, it was the same short list: page titles, meta descriptions, a sitemap, and redirects when they move something.
That’s it.
Nobody was using the readability scoring. Nobody was using the internal link suggestions. Those features were just running in the background, consuming resources, and adding to the update surface.
So Mantis SEO covers the essentials:
- Titles and meta descriptions: global templates with variables, per-post and per-term overrides
- Canonical URLs and robots directives: noindex, nofollow, controlled per page
- Open Graph and X card tags: social sharing image and copy, per post overrides
- JSON-LD structured data: Website, WebPage, Article, BreadcrumbList, Organization
- XML sitemaps: index and per post type, you choose what’s included
- Redirects: plain and regex rules, multiple HTTP status codes, auto-redirect on slug changes (in core)
- Yoast migration: one-click import of settings, post meta, term meta, and redirects
That last one was actually the first thing I built. Since most of our clients were coming from Yoast, the migration had to work before anything else. If you can’t switch without losing your existing titles, descriptions, and redirects, there’s no point.
What Mantis SEO doesn’t have:
- Readability scoring
- Content analysis
- Internal link suggestions
- AI writing tools
- A freemium upsell dashboard
Not because I couldn’t add them, but because my clients aren’t using those things anyway, and they’re a big part of what’s making the plugin slow.
We do plan on introducing an AI analysis feature to help create quality meta data for each post/page, but we will be leveraging the new AI Client in WordPress 7.0 to keep things light. And the feature will be optional.
One more thing that bothered me
When you delete Yoast, it leaves stuff behind. Database tables, post meta, plugin options, it stays in your database.
Yoast’s own support team has acknowledged this, with the response essentially being “that’s why you should test on staging first.”
That’s a reasonable answer for a developer. It’s not a great answer for the thousands of site owners who just want to switch plugins and move on.
When you delete Mantis SEO, it removes everything it ever created. Tables, options, post meta, term meta, all gone. That was a deliberate decision. I didn’t want to leave a mess.
Why I decided to make it available
Honestly, I built this for our clients to help reduce the time spent managing their sites and to deliver better performance results.
It’s the SEO plugin I wanted to use. Something lean, quiet, and low maintenance.
Something that wouldn’t generate support calls about slow dashboards or another round of annoying updates.
Once it was working well and the test results were solid, I figured we probably weren’t the only people in this situation.
WordPress support companies, developers managing client sites, and small business owners who just want their site to work without thinking about it, the need was clearly there.
We’re not trying to take over the SEO plugin space.
Yoast and the other major SEO plugins are solid products, and they’re a good fit for many people. But if you’re running straightforward WordPress sites and you’ve been feeling the overhead in your dashboard, in your update queue, in your client conversations, Mantis SEO might be exactly what you’ve been looking for.
It’s open source, it’s in public beta right now, and if you join the beta, you lock in 50% off the launch price.
Join the Mantis SEO beta for free access, 50% off at launch
Test details: Up to WordPress 7.0, PHP 8.5, identical plugin and theme setup across all three test states. Measured using Query Monitor on wp-admin/post.php. Tests are duplicated across multiple client sites. Results reflect consistent readings across runs.