All Kindle devices allow for instant access to the Amazon Kindle eBooks store where you can buy individual titles with no monthly subscription fee required. That said, Amazon Prime members can access free books via the Prime Reading service which would be subject to the current Prime membership rate.  Beyond that, you can get a Kindle Unlimited subscription for $11.99 per month to gain unlimited access to more than three million titles and thousands of audiobooks, and borrow up to 20 eligible Kindle Unlimited titles at a time at no extra cost. You can typically opt into a few free months of Kindle Unlimited with your Kindle purchase (or simply by being a Prime member) to give it a spin, and you can cancel the subscription at any time.