Operations | August 9, 2012 | 2 min read
New Guestbook Spam Prevention
In order to prevent spam being submitted on the Guestbook comments form, we have added a new section. To successfully submit a comment, a simple numerical question must be answered by selecting the correct answer from a dropdown list. The questions ask for answers to the sum of random numbers. This is our first attempt …
In order to prevent spam being submitted on the Guestbook comments form, we have added a new section. To successfully submit a comment, a simple numerical question must be answered by selecting the correct answer from a dropdown list. The questions ask for answers to the sum of random numbers. This is our first attempt at solving the spam issue. If the problem continues, we will refine our spam prevention techniques.
Why Spam-Proofing Matters
Guestbook spam isn’t just annoying—it can:
- Flood your guestbook with fake messages, ads, or malicious links
- Damage trust and clutter your page
- Force you to disable your guestbook entirely nutshell.com
That’s why ReservationKey introduced a simple dropdown math question—a smart first step in spam prevention
Proven Spam-Prevention Methods
1. Simple Math Challenge (Dropdown)
As ReservationKey does, present a random arithmetic question and require selecting the correct result. This catches basic bots easily
2. CAPTCHA
Use image or checkbox-based CAPTCHAs. Nearly every platform (Jimdo, InMotion, etc.) recommends them as a baseline anti-spam measure
3. Honeypot Fields
Add a hidden form field that only bots will fill. Since real users don’t see it, submissions that include it are automatically flagged as spam help.jimdo.com.
4. JavaScript/Flash-Rendered Forms
Render the form dynamically using JavaScript or Flash so bots that scroll raw HTML won’t see it aoeex.com. Just be cautious—some users disable scripts.
5. Manual Moderation + Email Verification
Set entries to moderation, or require email confirmation before entries get posted. This ensures you approve legitimate posts only inmotionhosting.com.
6. IP or Email Blocking
Blacklist repeat offenders at the IP or email level. While not foolproof—spammers use dynamic IPs—it helps reduce persistent abuse nutshell.com.
7. Third-Party Anti-spam Add-ons
Use services like CleanTalk, ProCaptcha Guestbook, or WordPress plugins. These integrate seamlessly and significantly reduce spam with minimal setup snaphost.com.
Layered Defense Strategy
Combining methods creates a strong defense:
TechniqueStrengthsMath dropdown + CAPTCHABlocks bots & basic scriptsHoneypot + JS-form renderingSneaks up on sophisticated botsModeration & blockingAdmin control and targeted defensesThird-party pluginsAccuracy with analytics and logs
ReservationKey’s Implementation
ReservationKey’s 2012 solution:
- A math dropdown combining simplicity and effectiveness
- A first step in layered defense—ready to be upscaled if spam persists