Ledger Blue

Ledger Blue is a premium cold storage device released in 2016 by Ledger SAS, the Paris based hardware security company now better known for the Nano S Plus, Nano X, Flex and Stax. Unlike the compact USB stick shape of Ledger's smaller devices, the Blue is built like a small tablet: a metal and glass body roughly the size of a large smartphone, with a 3.5 inch color touchscreen for reviewing and confirming every transaction directly on the device.

Inside, the Ledger Blue pairs a CC EAL5+ certified secure element chip with a separate general purpose microcontroller, keeping private keys isolated from the software that draws the screen, an architecture built on Ledger's BOLOS operating system and shared conceptually with other hardware wallets. This supports a "what you see is what you sign" model: the address and amount shown on the touchscreen must match what actually gets signed, guarding against malware on a connected computer that silently alters transaction data. It connects over USB or Bluetooth, runs on a rechargeable battery, and locks with a PIN protected recovery seed.

Despite the ambitious design, the Blue sold in far smaller numbers than Ledger's cheaper devices and received fewer firmware updates over time, which limited support for newer coins and tokens. Ledger eventually stopped selling it to retail customers and shifted its enterprise line elsewhere, only returning to a touchscreen form factor years later with Stax and Flex. As with any discontinued cold wallet, owners of a Ledger Blue should treat it as a legacy device and migrate funds to a currently supported wallet.