Title here
Summary here
Simple CAPTCHA
Not every site needs Google reCAPTCHA or Cloudflare Turnstile. Simple CAPTCHA provides human verification using math problems, custom text questions, or image challenges — all processed locally without sending data to external services.
Use Cases
- Protect forms without third-party dependencies
- Keep visitor data on your own server (privacy compliance)
- Work on intranets or sites without internet access
- Customize challenges with your own questions
CAPTCHA Types
Math CAPTCHA
Users solve simple arithmetic: “What is 7 + 4?”
| Difficulty | Examples |
|---|---|
| Easy | Single digits: 3 + 5, 8 - 2 |
| Medium | Larger numbers: 15 + 23, 42 - 18 |
| Hard | Three numbers: 5 + 12 - 3 |
Text Questions
Custom questions only humans would know:
- “What color is grass?”
- “How many legs does a dog have?”
- “What comes after Friday?”
You define the questions and accepted answers.
Image CAPTCHA
Distorted text users must type:
- Random alphanumeric string displayed as image
- Distortion and noise prevent OCR
- Optional case sensitivity
Settings
| Setting | Type | Default | Description |
|---|---|---|---|
| CAPTCHA Type | Select | Math | Math, text, or image |
| Math Difficulty | Select | Easy | Easy, medium, or hard |
| Text Questions | Repeater | — | Custom questions and answers |
| Image Style | Select | Distorted | Distorted or simple |
| Image Length | Number | 5 | Characters in image CAPTCHA |
| Case Sensitive | Toggle | Off | Require exact case for image |
| Skip Logged-in | Toggle | On | Don’t show to logged-in users |
| Error Message | Text | — | Custom verification error |
Protected Forms
WordPress Core Forms
| Form | Setting |
|---|---|
| Login | protect_login |
| Registration | protect_registration |
| Password Reset | protect_password_reset |
| Comments | protect_comments |
Switchboard Integrations
| Integration | Setting |
|---|---|
| Simple Forms | Always enabled |
| Magic Login | protect_magic_login |
| OTP Login | protect_otp_login |
Third-Party Forms
| Plugin | How to Add |
|---|---|
| Contact Form 7 | Add [switchboard_simple_captcha] tag |
| Fluent Forms | Add “Simple CAPTCHA” from Advanced fields |
Creating Text Questions
Good text questions should:
- Have obvious answers humans know
- Not require cultural knowledge bots might have
- Accept multiple valid answers
Example configuration:
Question: What color is the sky on a clear day?
Answers: blue, Blue, BLUE
Question: How many days are in a week?
Answers: 7, seven, Seven
Question: What season comes after winter?
Answers: spring, SpringProvide multiple answer variations to handle capitalization and spelling differences. Users shouldn’t fail because they typed “7” instead of “seven.”
Image CAPTCHA Requirements
Image generation requires the GD library, which is included in most PHP installations. If images don’t display:
- Check if GD is enabled:
php -m | grep gd - Install GD if missing:
apt install php-gd(Debian/Ubuntu) - Restart PHP/web server
Refresh Functionality
Users can refresh the CAPTCHA to get a new challenge:
- Useful if math problem is confusing
- Gets a new image if text is unclear
- Rate-limited to prevent abuse (10 refreshes per minute)
FAQ
Why use this instead of reCAPTCHA?
Privacy. Simple CAPTCHA processes everything locally — no data sent to Google. It’s also simpler to set up and works offline or on private networks.Are math problems secure enough?
Against basic bots, yes. Sophisticated bots can solve math, but they can also defeat basic reCAPTCHA. For high-security needs, use Turnstile or reCAPTCHA v3.Can bots read the image CAPTCHA?
Modern OCR can read some CAPTCHAs, but distortion helps. Image CAPTCHA is best as an additional hurdle, not sole protection for high-value forms.What if I enable multiple CAPTCHA modules?
Only one CAPTCHA renders per form. The modules coordinate to prevent duplicates. We recommend using just one CAPTCHA solution.Does this work without JavaScript?
Math and text CAPTCHAs work without JavaScript. Image CAPTCHA refresh requires JavaScript, but the initial image displays without it.Simple CAPTCHA is ideal for low-to-medium traffic sites wanting privacy-first protection. High-traffic sites facing sophisticated attacks should consider Cloudflare Turnstile or reCAPTCHA.
PRO
Upgrade to Pro
Get access to all 166 modules with a single license