Is Trezor safe?

Trezor is a hardware wallet made by SatoshiLabs, and its main safety claim is that the private key never leaves the device. Like any hardware wallet, it is only as safe as the owner's recovery backup and the transactions they approve. The real-world problems Trezor owners have faced have mostly been phishing, not broken devices.

Is Trezor a cold wallet?

Yes. Trezor's own guide describes it as a cold wallet whose private key stays offline. The device connects to a computer or phone, receives the transaction details, signs them inside the device and sends back only the signed transaction. The key itself is never sent out. The difference from apps on a phone is covered in hot wallet vs cold wallet.

Is Trezor open source?

Trezor says its device software has always been open source and is published on GitHub so anyone can audit it. Each device's bootloader checks the firmware signature and warns if the firmware is unofficial. The Safe 3, Safe 5 and Safe 7 add secure element chips, while the older Model One and Model T do not, a design difference covered in Trezor vs Ledger.

Is Trezor One still safe?

Trezor says the Model One and Model T remain safe to use. Its e-shop stopped selling both on January 8, 2026, but it commits to critical security updates until at least 2036 and basic maintenance until at least 2031. It adds that the Model One may not fully support future post-quantum standards because of hardware limits.

Physical theft is the known weak spot of the older models. In January 2020, Kraken Security Labs said it could pull the encrypted seed from a Trezor One or Model T with about 15 minutes of physical access, using a method called voltage glitching. Kraken said a software update could not fix it. Both Kraken and Trezor said the attack fails if an optional BIP39 passphrase is set.

Is trezor.io legit, and what about data breaches?

Yes, trezor.io is Trezor's official website. Trezor's support pages say to buy only from the official Trezor Shop, its Amazon storefront or an authorized reseller. A genuine device ships without firmware, and Trezor says one that already has firmware should not be used. The holographic seal over the port should be intact.

Customer data has leaked through outside suppliers. In January 2024, someone reached a third-party support ticketing portal, exposing names and emails of about 66,000 people who had contacted support, ForkLog reported, and some then got messages asking for their seed phrase. In August 2026, Trezor's shipping provider ShipMonk was hacked. BleepingComputer reported in September 2026 that the count had grown to about 81,000 customers, with names, addresses, emails and phone numbers exposed. It also reported fake emails sent from a real Trezor address after its email provider was breached.

Trezor says it will never ask you to enter your backup digitally. Any message asking for it is a scam, as our guide to crypto phishing explains.