You can check out websites like Comixology. They sometimes offer free graphic novels for promotion or as part of their freebies section. Another option is the digital library platforms such as OverDrive, which your local library may be affiliated with. Here, you can borrow graphic novels for free if they are available in their collection.
Goodreads is also a great place to start. There are often user - recommended lists of free graphic novels. Some independent authors and illustrators post their work for free on their personal websites or platforms like Gumroad. Just search for the genre or style of graphic novel you like on these sites and you might find some great free reads.
There are some websites dedicated to free e - books and graphic novels like Project Gutenberg. While it may not have the latest and most popular graphic novels, it has a decent collection of older and classic ones that are in the public domain and are completely free to download and read.