Apps similar to Forum Fortress include ALTCHA, which is free and open source. Other options are Antispam Bee, Cloudflare Turnstile, Akismet and StopForumSpam. In total there are seven Anti-Spam Tools like Forum Fortress for the web and self-hosting.
ALTCHA is a privacy-first solution built to help developers and website owners stop bots, spam, and automated abuse — without making things harder for real users. It replaces traditional CAPTCHA systems with a smarter, quieter approach to verification and threat detection.
Czechia
EU
Say Goodbye to comment spam on your WordPress blog or website. Antispam Bee blocks spam comments and trackbacks effectively, without captchas and without sending personal information to third party services. It is free of charge, ad-free and 100% GDPR compliant.
GermanyEU
Turnstile is Cloudflare's smart CAPTCHA alternative. It automatically chooses from a rotating suite of non-intrusive browser challenges based on telemetry and client behavior exhibited during a session.
Akismet checks your comments and contact form submissions against our global database of spam to prevent your site from publishing malicious content.
Your favorite and most trusted "one stop shop" for the prevention of forum & blog spam, trusted by over 200,000 forums...
Anti-Spam Features. CleanTalk protects your website from spam bots and spam in Comments, Orders, Widgets, Registrations, Bookings, And any custom web form, Contact Emails, Subscriptions, Checks the existing comments and users for spam.
United States
MxGuard is a cloud-based inbound email security gateway. Domains point their MX records at MxGuard, which scores every message and then rejects, quarantines, tags or forwards it to the customer's existing mail server.
United Kingdom
