The Chrome extension is free, but Grammarly also has some extra premium features available for a monthly fee.
Are extensions on Chrome free?
There are thousands of Chrome extensions. If you can imagine it, chances are there's an extension for it. There are literally thousands upon thousands of extensions. Here's the list I came up with -- all these extensions are free and work on Windows, Mac, and Linux.
Are Google Chrome Extensions safe?
Extensions are considered trusted when they're built by a developer who follows the Chrome Web Store Developer Program Policies. For new developers, it generally takes a few months to become trusted.