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Custom Captcha Field for Fluent Forms
Lightweight, self-hosted captcha field for Fluent Forms — image, math and question/answer challenges. No external services, no tracking.
The facts
- Rating
- 5★ from 1
- Active installs
- 100+
- Price
- Free
- Last updated
- 9 Jul 2026
- Added
- Aug 2024
- Requires WP
- 5.0
- Tested up to
- WP 7.0.4
- Requires PHP
- 7.4
- Downloads
- 1,820
Our analysis
AI-assistedCustom Captcha Field for Fluent Forms is a WordPress plugin that adds a captcha field to the Fluent Forms editor. It offers three types of challenges: image captcha, math captcha, and a question-and-answer format, all designed to help prevent spam submissions.
The plugin operates entirely on your server, ensuring no external data is sent. It includes additional spam defenses like time-trap and disposable email blocking, making it suitable for users looking to enhance form security without relying on third-party captcha services.
Best for: This plugin is best for WordPress users who utilize Fluent Forms and want to enhance their form security against spam.
What it does well
- ✓Offers three types of captcha challenges
- ✓No external services or API keys required
- ✓Includes additional spam defenses
- ✓Single-use challenges that expire after 15 minutes
- ✓Works well on cached pages
Where it falls short
- •Requires Fluent Forms to function
- •Limited information on user experience or support
Verdict
Custom Captcha Field for Fluent Forms provides a straightforward solution for adding captcha to forms. It is a practical choice for those seeking to improve form security without external dependencies.
From the developer
Lukman Hussain Nakib's own description of Custom Captcha Field for Fluent Forms, lightly tidied.
Adds a “Custom Captcha” field to the Fluent Forms editor with three challenge types:
- Image captcha — a 6-character code rendered as an image, with customizable text color and a transparent background by default so it blends with any form design
- Math captcha — a simple arithmetic question rendered as an image
- Question and answer — you define the question (field label) and the expected answer
Challenges are single-use and expire after 15 minutes. Answers are stored server-side via WordPress transients — nothing is exposed to the browser except the image itself. Visitors get a refresh button to request a new challenge, and the captcha automatically renews after each AJAX submission, so it also works on cached pages.
On top of the captcha you get two extra spam defenses:
- Time-trap (optional, off by default) — submissions completed faster than a human possibly could are rejected via an HMAC-signed timestamp; enable it and set the minimum submit time per field
- Disposable email blocking (optional, on by default) — rejects submissions where an email field uses a temporary/disposable email domain like mailinator.com or yopmail.com; extend the list with the
ffc_captcha_blocked_email_domainsfilter
Everything runs on your own server: no external captcha service, no API keys, no cookies, no visitor data sent anywhere.
Requirements
Fluent Forms is required. The PHP GD extension is recommended for image rendering (with a plain-text fallback when unavailable).
How To Use
- Activate the plugin
- Edit a form in Fluent Forms — a new “Custom Captcha” field appears in the editor
- Drop it into your form and pick the captcha type in the field settings
- Optionally set the text color, background color (RGB values like “68, 68, 68”, or “transparent”) and error message
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