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, Yubikey 5 Enhanced PIN Series, Security Key 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, Security Key Series, and Bio Series except on the 5C Nano form factor, which is too small to accommodate the 2D barcode.
All current YubiKeys are IP68-rated under the IEC standard 60529.
See the Yubico data sheet, What is a YubiKey? Product specification for additional certifications and specifications.
Verify the YubiKey and Packaging
Each YubiKey Series has its own packaging style. Be sure you received the YubiKey you ordered. See YubiKey packaging for images and description of the packaging used for each YubiKey Series.
When you receive your YubiKey, check that the packaging has not been tampered with. Check that the:
- YubiKey arrives in the correct Yubico packaging
- Plastic shell and seal is not broken or torn
- Cardboard wrap is intact and shows no signs of wear or tear
If you suspect any tampering, Submit a request.
When in doubt, you can also easily test that your YubiKey is a genuine YubiKey.
Go to Verify your Yubikey.
Insert your Yubikey.
Click Verify Device.
The response shows images your Yubikey form factor and firmware version.
YubiKey NFC
Important
This form factor is available for YubiKey 5, YubiKey FIPS, YubiKey CSPN, YubiKey Enhanced PIN, and Yubico Security Key.
YubiKey - NFC and USB-A Form
- Dimensions: 18mm x 45mm x 3.3mm
- Weight: 3.7g
- Physical Interfaces: USB-A, NFC
For more information:
- In this guide:
- Our Support article on the 1YubiKey 5 NFC <https://support.yubico.com/s/article/YubiKey-5-NFC>`_.
YubiKey Nano
Important
This form factor is available for YubiKey 5, YubiKey FIPS, YubiKey CSPN, and YubiHSM.
YubiKey Nano - USB-A Form
- Dimensions: 12mm x 13mm x 3.1mm
- Weight: 0.5g
- Physical Interfaces: USB-A
For more information:
- In this guide:
- Our Support article on the YubiKey 5 Nano.
YubiKey 5C
Important
This form factor is available for YubiKey 5, YubiKey FIPS, and YubiKey CSPN.
YubiKey - USB-C Form
- Dimensions: 12.5mm x 29.5mm x 5mm
- Weight: 1.8g
- Physical Interfaces: USB-C
For more information:
- In this guide:
- Our Support article on the YubiKey 5C.
YubiKey 5C Nano
Important
This form factor is available for YubiKey 5, YubiKey FIPS, and YubiKey CSPN.
YubiKey Nano - USB-C Form
- Dimensions: 12mm x 10.1mm x 7mm
- Weight: 0.7g
- Physical Interfaces: USB-C
For more information:
- In this guide:
- Our Support article on the YubiKey 5C Nano.
YubiKey 5Ci
Important
This form factor is available for YubiKey 5, YubiKey FIPS, and YubiKey CSPN.
YubiKey - USB-C and Lightning Form
- Dimensions: 12mm x 40.3mm x 5mm
- Weight: 2.9g
- Physical Interfaces: USB-C, Lightning®
For more information:
- In this guide:
- Our Support article on the YubiKey 5Ci.
YubiKey C NFC
Important
This form factor is available for YubiKey 5, YubiKey FIPS, YubiKey CSPN, YubiKey Enhanced PIN, and Yubico Security Key.
YubiKey - NFC and USB-C Form
- Dimensions: 18mm x 45mm x 3.7mm
- Weight: 4.3g
- Physical Interfaces: USB-C, NFC
For more information:
- In this guide:
- Our Support article on the YubiKey 5C NFC.
YubiKey Enhanced PIN Series
Important
The YubiKey Enhanced PIN series are available in form factors with either a USB-A or USB-C connector and the Near Field Communication (NFC) connection.
YubiKey Enhanced PIN Series - NFC and USB-A Form
- Dimensions: 18mm x 45mm x 3.3mm
- Weight: 3.7g
- Physical Interfaces: USB-A, NFC
YubiKey Enhanced PIN Series - NFC and USB-C Form
- Dimensions: 18mm x 45mm x 3.7mm
- Weight: 4.3g
- Physical Interfaces: USB-C, NFC
For more information, see:
- In this guide: YubiKey 5 Series - Enhanced PIN
- Our Support articles:
YubiKey Bio Series
Important
The Yubico Bio Key Series are a standalone series and are not within the YubiKey 5 Series. Though they share common functionality.
The YubiKey Bio series has two editions: FIDO Edition and YubiKey Bio Multi-protocol Edition. They are available with either a USB-A or USB-C connector in addition to the BIO sensor. NFC is not supported.
YubiKey Bio Series - Bio touch sensor and USB-A Form
- Dimensions: 18mm x 45mm x 3.35mm
- Weight: 4.3g
- Physical Interfaces: USB-A, Bio sensor
YubiKey Bio C Series - Bio touch sensor and USB-C Form
- Dimensions: 18mm x 45mm x 3.75mm
- Weight: 5.0g
- Physical Interfaces: USB-C, Bio sensor
For more information:
In this guide:
- YubiKey Bio Series Overview and YubiKey Bio Series Specifics
- Sensors: See Sensors
- LEDs: See LED Behavior
Our Support articles:
Security Key Series
Important
The Yubico Security Key Series are a standalone series and are not within the YubiKey 5 Series. Though they share common functionality.
The Yubico Security Key series are available in form factors with either a USB-A or USB-C connector and the Near Field Communication (NFC) connection.
Security Key Series - NFC and USB-A Form
- Dimensions: 18mm x 45mm x 3.3mm
- Weight: 3.7g
- Physical Interfaces: USB-A, NFC
Security Key Series - NFC and USB-C Form
- Dimensions: 18mm x 45mm x 3.7mm
- Weight: 4.3g
- Physical Interfaces: USB-C, NFC
For more information, see:
In this guide: Security Key Series Overview
Our Support articles:
YubiKey Markings
To aide in distinguishing the YubiKeys, the back of selected YubiKeys have specific markings.
FIPS-Specific Marking
All of the keys in the YubiKey 5 FIPS Series have the acronym FIPS inscribed on the backs of the YubiKeys, underneath the Data Matrix code. v5 runs up on the left side of the Data Matrix code, except for the YubiKey 5C Nano, which has it on the right.
YubiKey Series 5 FIPS-Specific Markings
YubiKey Bio Series Marking
The laser marking of the FIDO Edition of the YubiKey Bio Series was changed in March 2024. To distinguish the FIDO Edition from the Multi-protocol Edition, FIDO is marked on the back near the serial number and data matrix. YubiKeys of product type YubiKey Bio Series - FIDO Edition produced before March 2024 do not have FIDO marked on the back, instead they have only the serial number and data matrix on the back.
YubiKey Bio Series - FIDO Edition marked ‘FIDO’, March 2024 and later
YubiKey Bio Series - Multi-protocol Edition and YubiKey Bio Series - FIDO Edition prior to March 2024
CSPN-Specific Marking
All of the keys in the YubiKey 5 CSPN Series have the acronym CSPN inscribed on the backs of the YubiKeys, underneath the Data Matrix code.
YubiKey Series 5 CSPN-Specific Markings
Enhanced PIN Marking
All of the keys in the YubiKey 5 Enhanced PIN Series have the acronym EPIN and the serial number inscribed on the backs of the YubiKeys, underneath the Data Matrix code.
YubiKey Enhanced PIN Series Markings
Security Key Series Marking
All of the keys in the YubiKey 5 Security Key Series have the acronym FIDO inscribed on the backs of the Security Keys. This applies to both the Enterprise Edition and non-enterprise Security Keys.
As of January 2023, the markings on the back of the security keys are different for the non-enterprise and enterprise editions.
- Non-Enterprise edition of the security key series the back only has FIDO inscribed.
- Enterprise Edition security key series the back has FIDO, scan code, and serial number inscribed.
Non-Enterprise Security Key Series Markings
Enterprise Security Key Series Markings
YubiKey ID Numbers
Various security protocols and use cases require valid devices identification. To locate the ID numbers:
- For Authenticator Attestation Globally Unique Identifier (AAGUID) see YubiKey hardware FIDO2 AAGUIDs.
- For USB Product Identifier (PID), see How to find the USB Product ID (PID) of your YubiKey and YubiKey USB ID values.
- For U2F attestation Object Identifier (OID), see The YubiKey FIPS 4 Series Technical Manual, U2F Attestation.
Care and Cleaning
YubiKeys, including YubiKey Bio, are IP68-rated. This means you can expect the keys do not allow ingress of dust up to level 6 and a measure of water resistance, up to level 8 as defined by the International Electrotechnical Commission, for ingress protection (IP). See European Standards, BS EN 60529:1992+A2:2013.
To clean the YubiKey, including YubiKey Bio sensors, use wipes impregnated with no more than 70% isopropyl alcohol.