As of 2014, Amazon's Kindle Fire HDX line of tablets support a 4G connection for an extra fee. The service is supplied through AT&T or Verizon, and requires a monthly fee for service. The older Kindle Fire HD does not include a cellular modem, and can only connect using Wi-Fi.
Amazon's Kindle Paperwhite e-reader is available in both Wi-Fi and 3G configurations. The 3G Paperwhite offers free 3G service, but unlike previous models, the connection can only be used to download from Amazon's servers or connect to Wikipedia. The basic Kindle model without the touchscreen is only available with a Wi-Fi connection.