What is an online identifier in GDPR?

An identifier is any information that can be used to recognise an individual. According to Article 4(1) GDPR, an identifier could be “a name, an identification number, location data, an online identifier.”

Online identifiers are information related to an individual’s tools, applications, or devices according to Recital 30 of the GDPR. When combined with other unique identifiers, over time, online identifiers can be used to recognize an individual.

Examples of online identifiers

  • Internet Protocol address
  • Internet cookies
  • Beacons, pixel tags
  • Mobile ad identifiers
  • Device fingerprints
  • Radiofrequency identification (RFID) tags