All in One SEO vs Slim SEO: guided setup against no setup at all
Slim SEO is the better choice unless you specifically want a guided, feature-rich admin. Per request it cost +10.0 ms of PHP time and 2 database queries, where All in One SEO cost +53.5 ms and 22, and it still printed more schema and a sitemap with images. All in One SEO offers what Slim SEO deliberately leaves out: screens, settings and hand-holding.
Both plugins went through the same protocol in our seven-plugin test: free editions, untouched settings, a shared WordPress 7.1 site and a no-plugin baseline to subtract. Our own plugin, Hydrogen SEO, plays no part in this matchup.
The numbers
| Measured | All in One SEO 5.0.1.1 | Slim SEO 4.10.1 |
|---|---|---|
| Front-end PHP time added | +53.5 ms | +10 ms |
| Peak memory added | +14.5 MB | +2 MB |
| Database queries added | +22 | +2 |
| Hooks registered | +100 | +51 |
<head> bytes added | +6,668 | +1,649 |
| Meta description by default | Yes | Yes |
| JSON-LD types printed | 8 | 10 |
| Open Graph / X tags | 6 / 3 | 11 / 2 |
| Sitemap URLs listed | 73 | 73 |
| Sitemap image entries | 0 | 40 |
lastmod coverage | 73 / 73 | 50 / 73 |
| Custom database tables | 9 | 0 |
| Autoloaded options added | +14.6 KB | -0.2 KB |
| Plugin package size | 24.4 MB | 1.4 MB |
| Block editor assets | 130 files, 3,543 KB | 14 files, 187.7 KB |
| After deactivation | No reduction: 14.5 KB still autoloading | Releases everything |
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. Bold marks the better number in each row. Full method: how we tested.
What the numbers mean
These two have opposite ideas of what an SEO plugin should be. All in One SEO shows you everything: a 511 KB dashboard, the heaviest admin page we measured, and 130 files (3,543 KB) in the block editor. Slim SEO shows you almost nothing: it registered zero admin menu items and put just 187.7 KB of assets in the editor.
The server costs follow the same line. Peak memory climbed +14.5 MB under All in One SEO and +2.0 MB under Slim SEO. The <head> grew 6,668 bytes versus 1,649, the biggest and smallest growth in the field, and the download weighs 24.4 MB versus 1.4 MB, again the two extremes. It creates nine custom tables; Slim SEO creates none. Its autoloaded options grew by 14.6 KB, while Slim SEO's came out fractionally below baseline. On deactivation Slim SEO released everything and All in One SEO released nothing.
Output mostly favors Slim SEO. Slim SEO's graph held 10 JSON-LD types in 3,828 bytes; All in One SEO's held 8 in 4,544. Both sitemaps counted 73 URLs, yet only Slim SEO's carried the 40 featured images, and the free All in One SEO sitemap had no image entries. Slim SEO printed 11 Open Graph tags against 6. All in One SEO wins two rows: it printed 3 X tags against Slim SEO's 2, and it stamped lastmod on all 73 sitemap URLs, where Slim SEO left 23 unstamped. Both generate meta descriptions.
So the trade is not output for cost; Slim SEO gives you comparable or better output for a fraction of the cost. The trade is control and guidance. If you or your client want to see settings, follow a setup wizard and manage features from screens, All in One SEO provides that and Slim SEO does not.
Choose All in One SEO if
- You want a guided setup and a full settings interface.
- You want every one of the 73 sitemap URLs stamped with
lastmod. - You want many features and add-ons in one product family.
- You are handing the site to someone who expects visible SEO screens.
Choose Slim SEO if
- You want the leanest install in the field: a 1.4 MB download, 1,649 extra
<head>bytes and zero custom tables. - You want 10 schema types and all 40 featured images in the sitemap without changing a setting.
- You want nothing left behind after deactivation.
- You want a plugin you install and then never think about.
Switching between them
Leaving All in One SEO for Slim SEO? Slim SEO's migration tool can read All in One SEO data, but run it while the old plugin is still installed: All in One SEO stores per-post data in its own custom tables, so the import has to come before any uninstall. For the reverse move, All in One SEO ships importers for several major plugins; confirm in its documentation whether Slim SEO is on the list. Slim SEO has few settings to map, so put your checking time into per-post titles, descriptions and redirects. Hydrogen SEO reads data from either one; the import walkthrough covers the details.
Common questions
Is Slim SEO lighter than All in One SEO?
Much lighter in our benchmark: +10.0 ms and 2 queries against +53.5 ms and 22, with a 1.4 MB package against 24.4 MB and no tables against nine.
Does Slim SEO have a settings dashboard?
Very little. It added no admin menu items in our test and works from defaults. All in One SEO has a full dashboard, which measured 511 KB.
Which prints more schema?
Slim SEO: 10 JSON-LD types in 3,828 bytes against All in One SEO's 8 in 4,544 bytes.