Physical Attributes
The serial number is printed on the back of every YubiKey in the YubiKey 5 Series, YubiKey 5 FIPS Series, YubiKey 5 CSPN Series, and YubiKey Bio Series. The 2D barcode (Data Matrix code) of the serial number is also printed on the back of every YubiKey in the 5 Series (as well as on the FIPS and CSPN) except on the 5C Nano form factor, which is too small to accommodate the 2D barcode.
In addition, all of the keys in the YubiKey 5 FIPS Series have the acronym “FIPS” underneath the Data Matrix code on the back, along with “v5” running up the left side of the Data Matrix code, except on the YubiKey 5C Nano, which has it on the right.
All current YubiKeys have been IP68-rated under the IEC standard 60529.
YubiKey 5 NFC
Important
The attributes listed below also apply to the YubiKey 5 NFC FIPS, YubiKey 5 NFC CSPN, Security Key NFC, and the Security Key NFC - Enterprise Edition.

- Dimensions: 18mm x 45mm x 3.3mm
- Weight: 3g
- Physical Interfaces: USB, NFC
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
YubiKey 5 Nano
Important
The attributes listed below also apply to the YubiKey 5 Nano FIPS, and the YubiKey 5 Nano CSPN.

- Dimensions: 12mm x 13mm x 3.1mm
- Weight: 1g
- Physical Interfaces: USB
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
YubiKey 5C
Important
The attributes listed below also apply to the YubiKey 5C FIPS and the YubiKey 5C CSPN.

- Dimensions: 12.5mm x 29.5mm x 5mm
- Weight: 2g
- Physical Interfaces: USB
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
YubiKey 5C Nano
Important
The attributes listed below also apply to the YubiKey 5C Nano FIPS and the YubiKey 5C CSPN.

- Dimensions: 12mm x 10.1mm x 7mm
- Weight: 1g
- Physical Interfaces: USB
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
YubiKey 5Ci
Important
The attributes listed below also apply to the YubiKey 5Ci FIPS and the YubiKey 5Ci CSPN.

- Dimensions: 12mm x 40.3mm x 5mm
- Weight: 2.9g
- Physical Interfaces: USB, Lightning®
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
YubiKey 5C NFC
Important
The attributes listed below also apply to the YubiKey 5C FIPS, YubiKey 5C NFC CSPN, Security Key C NFC, and the Security Key C NFC - Enterprise Edition.

- Dimensions: 18mm x 45mm x 3.7mm
- Weight: 4g
- Physical Interfaces: USB, NFC
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
YubiKey Bio Series
The YubiKey Bio - FIDO Edition is available in the USB-A format, while the YubiKey C Bio - FIDO Edition is available in the USB-C format, both have a maximum transfer rate of 12 Mbps.
The sensors and LEDs behave the same way in both formats.

YubiKey Bio - FIDO Edition

YubiKey C Bio - FIDO Edition
Sensors
The YubiKey Bio recognizes two interactions, one a touch, and the other a fingerprint. Its recognition of the fingerprint - or lack thereof - is communicated through the LEDs. See LED Behavior.
On the YubiKey Bio, the silver-colored bezel encircling the fingerprint sensor provides the grounding plane required to read the fingerprint.
Biometric Touch: | |
---|---|
When prompted to have the YubiKey Bio read your fingerprint from the fingerprint sensor, be sure to touch at least a tiny part of the ring. If you use your little finger to touch only the center of the fingerprint sensor, the key does not read the fingerprint. | |
Plain Touch: | When prompted to touch the YubiKey Bio but not explicitly asked for the fingerprint, touch both the bezel and the fingerprint sensor, even though the fingerprint is not read. |
Finger Print Tips provides detailed instructions on using the fingerprint sensor.
LEDs
The YubiKey Bio has a green LED and an amber LED to provide direct feedback. It flashes when the key is ready for interaction or is communicating something about the interaction. LED Behavior provides detailed descriptions.
Ratings
The YubiKey Bio has been IP68-rated under the IEC standard 60529.
Care and Cleaning
To clean the YubiKey and sensor, use only wipes impregnated with no more than 70% isopropyl alcohol.
Operational Data
- Dimensions
- YubiKey A Bio: 18mm x 45mm x 3.35mm
- YubiKey C Bio: 18mm x 45mm x 3.75mm
- Weight: YubiKey Bio A: 4.5g; YubiKey Bio C: 5.0g
- Operating Temperatures: 0 °C - 40 °C (32 °F - 104 °F)
- Storage Temperatures: -20 °C - 85 °C (-4 °F - 185 °F)
FIPS-specific Marking

CSPN-specific Marking

Security Key Series Marking
The color of the non-Enterprise edition of the Security Key Series was changed to black in January 2023. To distinguish the Security Key Series from the YubiKey 5 Series, FIDO is inscribed on the back.

Like the non-Enterprise edition of the Security Key Series, the Enterprise edition of the Security Key Series also has FIDO inscribed on the back to distinguish them from a YubiKey 5 Series. In addition, the serial number is inscribed on the back of each key in the Enterprise edition of the Security Key Series.

To contact Yubico Support, submit a request.