Which SD Card Is Compatible With Kindles?

By Matt Koble

Amazon dropped support for SD cards with the Kindle 2.
i Mario Tama/Getty Images News/Getty Images

While an SD card slot may seem like an obvious feature for the Amazon Kindle, most models don't actually have SD slots. Only one model – the first-generation Kindle – includes such a slot. Subsequent Kindle models have more internal memory than first-generation devices, so Amazon did not include an SD slot.

First-Generation Kindle

First-generation Kindles are the only e-readers produced by Amazon with SD card slots at the time of this writing. These early Kindles have a slot for a standard SD card up to 4GB, according to Amazon's website. Higher capacity cards and cards that use the newer SDHC format are not officially supported; smaller mini- and microSD cards won't fit in the first generation Kindle either. The extra storage space afforded by an SD card is a practical requirement on this Kindle model, as it only has 180MB of internal storage space accessible to the user.

Kindle Fire

Kindle Fire tablets do not have SD card slots. According to Amazon's official specification sheet, Fire tablets have an internal SD card that is used for device storage. This internal card is not user-removable. The storage capacity associated with the card depends on your Kindle Fire model and price point.

Cloud Storage

While only one generation of the Kindle has SD support, owners of newer Kindles don't have to worry about running out of storage space. When the internal storage fills up, new or previously read content can be stored on Amazon's cloud storage service. Cloud storage acts like extra memory, except it resides on the Internet instead of on a physical card in your Kindle. Content stored in the cloud is accessible on Kindle e-readers by selecting "Archived Items" from the menu.

SD Card Structure

If you have a first-generation Kindle, it's important for you to know the specific folder structure required on the card. If you place content in the wrong folder, your Kindle may not be able to find or access the content. When you plug your Kindle into your computer and open the SD card's main directory, you should see three folders: Documents, Music and Audible. Readable content using one of the AZW, TXT, MOBI or PRC file formats goes in the Documents folder, but MOBI and PRC files cannot be read if they contain digital rights management software. MP3 files go in the Music folder, while AA audiobook files go in the Audible folder.