Anti-spam is one of the popular plugins with over 200,000 active installed.

These plugin blocks spam only in comments. You can configure to move them in spam area so you can review it and convert to normal if needed.

Anti-spam is an open-source and GDPR compliant.

Stop Spammers – as the name says it all.

Annoyed dealing with spams in comment, login or contact form? This plugin validates spams with more than 20 algorithms to ensure no SPAM exist on your WP site.

You can configure to show OpenCaptcha, Google ReCaptcha, SolveMedia captcha for suspicious activities. It’s an open-source software.

Cerber Security defends your site against hacker attacks, spam, Trojan, and malware.

Mitigate brute force attacks by limiting the number of login attempts through the login form XML-RPC / REST API requests or using auth cookies.

Highlights

• Permits or restrict access by White IP access list and Black IP access list with a single IP, IP range or subnet.
• Automatically detects and moves spam comments to trash or deny it completely.
• Citadel mode for massive brute force attacks.
• Protection against DDOS attacks.
• Hides wp-login.php and wp-signup.php from possible attacks.
• Immediately blocks an IP or a sub-net when attempting to log in with a non-existent username.

The plugin is free.

Clean Talk is an Anti-Spam plugin which provides end to end spam protection for WordPress websites. The plugin is updated frequently providing and hence blocks new spam techniques.

Some of its key features are:

• Checks and removes the existing spam comments and spam users.
• It can filter comments, emails, registrations, contacts, Widgets etc.
• Use stop words to filter and block comments
• Keep the bad bots away

Clean Talk is GDPR compliant.

Akismet is used on more than 5 million WP sites. It validates spam from comments and contact from against global database.

Highlights

• Automatic monitoring and filtering of comments
• Flag and status history for all comments
• Dashboard for moderators to see approved comments, user wise.
• Discard feature that blocks all the frequently reported spam, to speed up your site by using less disk space.

Sucuri, one of the reputable in providing comprehensive security services to a site from small to big. You can monitor security-related events and check your site against popular blacklist including Google, Norton, AVG, Phish Tank, Yandex, etc.

There are four main features of the plugin.

• Auditing – check what’s wrong
• Monitoring – get notified when something goes wrong
• Malware Scanning – scan for known malware
• Hardening – apply a necessary configuration to protect from online vulnerabilities

Shield Security by iControlWP ensures the protection of your websites through its cutting-edge features like vulnerability scanner, plugins and themes scanner.

Highlights

• Get notified when new vulnerability found on your site
• Let Shield update your WordPress automatically
• Scan your files regularly to find a malicous code

Shield is one of the best plugins to fight with SPAM and inject security headers.