Fieldstone vs Advanced Custom Fields
Both let you build custom fields with a visual editor and read them in your theme. The differences are in where your data is stored, how you move an existing site across, and how the plugin is priced. Here's an honest side-by-side.
At a glance
| Capability | Fieldstone | ACF |
|---|---|---|
| Storage model | Dedicated, indexed custom tables — one row per post | Two wp_postmeta rows per field |
| Postmeta compatibility | ✓ Mirror on by default (exports, backups, SEO, search) | ✓ Native — values live in postmeta |
| Query by field value | ✓ Real columns you can index | Via meta queries on postmeta |
| Visual field-group editor | ✓ | ✓ |
| Custom post types & taxonomies | ✓ Built in | ✓ (ACF 6.1+) |
| Location rules & conditional logic | ✓ | ✓ |
| Repeater, Flexible Content, Clone | ✓ Pro | ✓ Pro |
| Relational, Gallery, Options pages | ✓ Pro | ✓ Pro |
| Block bindings | ✓ Pro — binds core blocks (WP 6.5+) | ✓ ACF Blocks (custom blocks) |
| Front-end forms | ✓ fstn_form() — validation, honeypot, rate limiting | ✓ acf_form() |
| One-click import from ACF | ✓ Deterministic, data untouched | — |
| ACF-style template API | ✓ fstn_get_field(), row loops | ✓ get_field(), row loops |
| Local JSON / version control | ✓ | ✓ |
| REST API & WP-CLI | ✓ | ✓ |
| Generate fields with AI | ✓ Optional, bring-your-own key, off by default | — |
| Licence | One-time & annual plans, 30-day money-back | Annual subscription |
Comparison reflects publicly documented features at the time of writing; ACF is a trademark of its owner and is used here for identification only.
Where Fieldstone is different
1. Custom-table storage, not postmeta
ACF stores each field as two rows in wp_postmeta (the value and a reference to its definition). On content-heavy sites that table grows quickly and every field read is a meta lookup. Fieldstone keeps one indexed row per post in a dedicated table, so reads are direct and you can put a real database index on any field. A postmeta mirror keeps a plain copy where the rest of the ecosystem expects it, at the cost of a second write on save. We measured both sides on 10,000 posts: see the benchmark, including where Fieldstone is slower.
2. A real way off ACF
Switching custom-field plugins usually means rebuilding every group by hand. Fieldstone imports your ACF groups in one click, recreates them with its own storage, and leaves your ACF data completely untouched so you can run both and roll back freely. See the migration guide.
3. The same workflow you already know
The editor, location rules, conditional logic and template functions all follow the patterns ACF developers expect — including the have_rows() / the_row() / get_sub_field() loop. Migrating a theme is mostly a find-and-replace of the function prefix.
4. Simpler pricing
Fieldstone Pro comes with a 30-day money-back guarantee, and staging and development sites are always free. See the current plans.
When to stick with ACF
If your site is small, your postmeta isn't a problem, and you rely on a specific third-party ACF add-on, ACF's large ecosystem may still be the better fit. Fieldstone reads ACF data on import but is not a drop-in replacement for every ACF extension. The honest test: install Fieldstone free alongside ACF, import one group, and see whether the storage and workflow suit you before committing.
Or start free — install Fieldstone from WordPress.org and try the ACF import.