Captcha Tools
Get told when a new site picks a Captcha tool.
Stackdar watches every launch we detect and sends you the ones that ship with anything in Captcha, your competitors' tools included, by email, Slack or webhook. On every plan, from £15 a month.
See how alerts workThe most-adopted captcha tool we track is Cloudflare Turnstile (31,546 sites). We've detected 39 captcha tools across 33,557 public sites.
Captcha tools we've detected
| Tool | 90‑day | Sites |
|---|---|---|
Cloudflare Turnstile
site ↗
Privacy-friendly CAPTCHA replacement.
|
31546 | |
hCaptcha
site ↗
Privacy-friendly bot-detection challenge service, marketed as a Google reCAPTCHA alternative.
|
2020 | |
Friendly Captcha
site ↗
Privacy-friendly, proof-of-work CAPTCHA alternative for forms.
|
106 | |
DS CF7 Math Captcha
site ↗
WordPress plugin that adds a math question captcha to Contact Form 7 forms to block spam submissions.
|
65 | |
|
TNcode
Open source slider puzzle captcha library for PHP and JavaScript forms.
|
39 | |
|
CAPTCHA 4WP
WordPress plugin that adds Google reCAPTCHA and hCaptcha protection to site forms.
|
34 | |
|
WP Captcha
WordPress plugin that adds captcha protection and brute force login defence.
|
30 | |
i13 reCaptcha
site ↗
WordPress and WooCommerce plugin range from I13 Web Solution that adds Google reCAPTCHA to login, registration and checkout forms.
|
27 | |
|
Cap (CAPTCHA)
Open-source proof-of-work CAPTCHA alternative using WebAssembly.
|
26 | |
NetEase Yidun
site ↗
NetEase anti-bot, captcha, and fraud-prevention service.
|
18 |
Showing top 10 of 39 captcha tools by adoption. 29 more not shown.
The StackScope API serves every captcha tool and the launches using each, filterable and exportable, from £15 a month.
Launches using Captcha tools
| Launch | Launched | Score |
|---|---|---|
| Srmed | Sep 1, 2026 | 8.5 |
| RevenueSol | Sep 1, 2026 | 10.0 |
| Farm Planner Online | Sep 1, 2026 | 9.1 |
| Rectiva | Sep 1, 2026 | 10.0 |
| BuyUKeSIM | Sep 1, 2026 | 10.0 |
| Clypse | Sep 1, 2026 | 10.0 |
Often built with
Categories the captcha sites we track also commonly use: