If you're using WordPress and want a plugin to find broken internal and external links and fix them, Link Whisper is a good choice. The plugin uses artificial intelligence to suggest links to your content, to boost your Google search engine ranking and to keep your internal linking system healthy. It's got features like automated link suggestions, broken link repair and multisite support, so it's easy to use and fit into your existing workflow.
Another option is SEOJuice. It automates internal linking with AI to help you save time and improve your website's search engine optimization. SEOJuice features include contextual keyword management, customizable keyword exclusion and support for multiple e-commerce and website-building platforms, including Shopify and NextJS. It also comes with a 7-day free trial so you can test it before signing up for a plan.