Hydrogen SEO vs The SEO Framework: the lightest plugin against ours
The SEO Framework is lighter than Hydrogen SEO, and our own benchmark says so. It added +8.0 ms of PHP time and zero queries per request; Hydrogen SEO added +12.9 ms and one. If raw cost and a quiet admin are what you want, and you do not want AI features, The SEO Framework is the better choice.
We build Hydrogen SEO. The SEO Framework won our seven-plugin benchmark overall, winning or sharing seven of sixteen categories. Hydrogen SEO's case against it is narrower: a fuller default sitemap and an AI layer that The SEO Framework leaves out on purpose.
The numbers
| Measured | Hydrogen SEO 0.0.18 | The SEO Framework 5.1.4 |
|---|---|---|
| Front-end PHP time added | +12.9 ms | +8 ms |
| Peak memory added | +4.5 MB | +2 MB |
| Database queries added | +1 | +0 |
| Hooks registered | +22 | +8 |
<head> bytes added | +4,259 | +3,821 |
| Meta description by default | Yes | Yes |
| JSON-LD types printed | 10 | 9 |
| Open Graph / X tags | 10 / 5 | 10 / 5 |
| Sitemap URLs listed | 72 | 51 |
| Sitemap image entries | 40 | 0 |
lastmod coverage | 72 / 72 | 51 / 51 |
| Custom database tables | 1 (2 with the 404 Monitor on) | 0 |
| Autoloaded options added | +0.4 KB | +4.2 KB |
| Plugin package size | 4.6 MB | 2.9 MB |
| Block editor assets | 2 files, 700.4 KB | 25 files, 77.6 KB |
| After deactivation | +0.2 KB left autoloading | Releases everything (exact baseline) |
Measured on one WordPress 7.1 install (PHP 8.2, MySQL 8.0, Twenty Twenty-Five, 40 posts), each plugin alone with default settings, against a no-plugin baseline. Each column heading names the version that was measured. Bold marks the better number in each row. Full method: how we tested.
Hydrogen SEO's figures were measured on 0.0.18 and have not been re-run on later versions. The custom tables row is the exception: it is counted from the 0.0.31 source. A default install has one table, for the internal link counter. Switching on the 404 Monitor, which is off by default, creates a second for its log. Deleting the plugin removes both.
What the numbers mean
On cost, The SEO Framework wins almost everywhere. It used +2.0 MB of memory against Hydrogen SEO's +4.5 MB, registered 8 hooks against 22, and ships a 2.9 MB package against 4.6 MB. Neither created a custom table in the benchmark; Hydrogen SEO has since added one for link counts (0.0.30) and an optional one for the 404 Monitor, two in all by 0.0.31, where The SEO Framework still has none. Autoloaded options are the one cost row Hydrogen SEO takes: +0.4 KB against +4.2 KB. On deactivation The SEO Framework restored the baseline exactly; Hydrogen SEO left 0.2 KB.
The editor is where the gap is widest. The SEO Framework loaded 77.6 KB of its own assets into the block editor, the lightest of any plugin. Hydrogen SEO loaded 700.4 KB in 2 files, because its editor UI is a single React bundle. That is about nine times The SEO Framework's weight. Dashboard HTML is nearly identical (130.3 KB against 131.2 KB).
Output is where Hydrogen SEO earns its place. Both print a meta description, a canonical, 10 Open Graph and 5 X tags. Schema is close: 9 types in 1,881 bytes for The SEO Framework, 10 in 2,071 for Hydrogen SEO. The sitemap is the real difference. The SEO Framework ships a deliberately minimal flat sitemap: 51 URLs, posts and pages only, no index file and no image entries. Hydrogen SEO's listed 72 URLs including taxonomy archives, 40 featured images and a lastmod on every URL. Whether you need archives and images in your sitemap is a judgment call; The SEO Framework's choice is an opinion, not a bug.
The other difference is philosophy. The SEO Framework favors automation over configuration and has no AI features by design. Hydrogen SEO has AI writing help and an agent that takes plain-language jobs, behind a free account, and it is still Beta software with far less field history.
Features: free, paid or not offered
| Feature | Hydrogen SEO 0.0.31 | The SEO Framework 5.2.1 |
|---|---|---|
| Search engine verification codes | Free | Free |
| IndexNow instant indexing | Free | — |
| Redirect manager | Free | — |
| 404 monitor | Free | No |
| SEO column on the Posts screen | Free | Free |
| SEO fields in Quick Edit | Free | Free |
| Attachment page redirects | Free | — |
| Author and date archive controls | Free | Free |
| RSS feed text | Free | — |
| max-snippet and preview controls | Free | Free |
| Primary category | Free | Free |
| Internal link counts on the Posts screen | Free | — |
| Automatic image alt attributes | Free | — |
| Table of contents block | Free | — |
| HTML sitemap | Free | — |
| Pillar or cornerstone content flag | Free | — |
| Crawl cleanup switches | Free | — |
| Video sitemap | Free | — |
| Google News sitemap | Free | — |
| llms.txt | Free | — |
This table is not benchmark data. It is based on each plugin's WordPress.org listing, the code of its free version there, and its official documentation and pricing pages, checked on 12 November 2026, for the version in each column heading. Free means the feature is in the plugin's own free version. Paid means it needs that plugin's paid version or a paid add-on. No means the plugin's listing says it does not offer it. A dash means we could not confirm it either way; it does not mean the feature is missing. A row says a feature exists, not how complete it is. Plugins change, so check the plugin's own site before relying on a cell. If a cell is wrong, tell us and we will correct it.
Choose Hydrogen SEO if
- You want taxonomy archives and featured images in your sitemap, with full
lastmod. - You want AI help for meta, social fields and alt text, or an agent for site-wide jobs.
- You want a dashboard with audits and a health score in one React admin.
- You accept a heavier editor (700 KB) and Beta status in exchange.
Choose The SEO Framework if
- You want the lowest server cost we measured: +8.0 ms, +2.0 MB, 0 queries.
- You want the lightest editor (77.6 KB) and an admin that barely changes.
- You want a plugin that leaves nothing behind when deactivated.
- You do not want AI features and prefer sensible automation to configuration.
Switching between them
Hydrogen SEO's Tools → Import SEO Data detects The SEO Framework and imports its settings, per-post fields and per-page redirects, with a dry run first and an Undo afterwards. The SEO Framework has no title template syntax, so its separator, site name and tagline branding are rebuilt as Hydrogen SEO templates that render the same titles. The import documentation walks through each step. Moving to The SEO Framework from another plugin, check its current documentation for migration options before you start.
Common questions
Is The SEO Framework faster than Hydrogen SEO?
Yes. In our benchmark The SEO Framework added +8.0 ms and 0 queries; Hydrogen SEO added +12.9 ms and 1 query. The SEO Framework was the lightest plugin we tested overall.
Why is The SEO Framework's sitemap smaller?
It ships a flat sitemap with posts and pages only: 51 URLs and no image entries at defaults. Hydrogen SEO's included taxonomy archives and featured images, 72 URLs and 40 images, each with lastmod.
Does The SEO Framework have AI features?
No, by design. Hydrogen SEO includes AI writing tools and an agent, which require a free hydrogenseo.com account. Every non-AI feature in Hydrogen SEO works without an account.