Formidable Forms vs Mailster
Compare WordPress plugins and tools side by side. Pick products with “Compare” in the software directory.
| Feature | Formidable Forms v7.0 · checked 23 Oct 2026 Free + paid · ★ 4.8/5 Visit Details | Mailster v2.0.3 · checked 23 Oct 2026 Paid · ★ 3.5/5 Visit Details |
|---|---|---|
| At a glance | ||
| Active installs | 300,000+ | 7,000+ |
| Last updated | October 16, 2026 | October 15, 2026 |
| Editions | Formidable Forms · Formidable Pro ($) | Mailster Compatibility Tester · Mailster ($) |
| Pros | Free drag-and-drop builder with unlimited forms; Stripe and PayPal payment forms in the free version; Spam protection options such as honeypot and reCAPTCHA | Server, PHP and mail checks in one admin page; Clear pass, warning or error result for each check; Free to run before buying Mailster |
| Cons | Multi-page forms, file uploads and conditional logic need Pro; Admin shows Pro upgrade screens and prompts; Calculated fields are unclear in the free version docs | Offers a Mailster licence purchase on the same page; Downloads the paid Mailster plugin after checkout; Only checks readiness, it is not the newsletter plugin |
| Mentioned in our posts | 2 | 2 |
| More features | ||
| Other features | Built-in MCP server for AI clients, Visual form styler, Form actions such as notifications after submit | Server and PHP compatibility checks, Mail delivery check through wp_mail, Admin page for running tests, Mailster licence checkout and download ($) |
| Integrations | ||
| Payment | Stripe, PayPal, Square | Freemius checkout |
| Plugins | — | Mailster download endpoint |
| Other | Google reCAPTCHA, StopForumSpam | — |
| Requires WordPress | 6.3 | 6.0 |
| Requires PHP | 7.0 | 7.4 |
| Tested up to | 7.1 | 7.1 |
| Phones home | Only if you agree | No |
| External services | app.squareup.com, sandbox.formidableforms.com, api.stopforumspam.org, feedback.strategy11.com | mailster.co |
| Blocks | 1 | — |
| Shortcodes | 3 | — |
| Custom tables | 2 | — |