question?

Is CodeIgniter a really strong platform regarding security? Do I have to update any themes or plugins or whatever every now and then like I do in Wordpress? Is there a plugin or any way to migrate the existing websites to CodeIgniter without paying a fortune or getting a master degree in computing? Can this migration be done in an SEO friendly way without losing my current google rankings?

Thank you very much in advance for your time and patience.

CodeIgniter (CI) provides many tools that allow the developer to create secure websites. The framework codebase is well established and stable. There aren't any vulnerabilities that I'm aware of, but it does require an experienced and security conscious developer to write code that doesn't create issues.

CI does not supply any themes or plugins or whatevers. All libraries that might fit that description are developed and offered by third-party sources. Each will have to be evaluated for security and suitability.

I am not aware of any plugin or script that will assist in migrating to CI.

SEO friendly URLs are the default for CI and most other aspects of SEO are easily implemented. It should be possible to maintain the google ranking.