There are various type of Identifiers widely used in AD Tech or Audience Measurement Industry - IDFA, AAID, Hashed Device ID, Safari ID, Firefox ID and etc. Unfortunately these formats are not compatible each other except IDFA and AAID. The difference between IDFA and AAID is lowercase/uppercase in Latin characters.
| ID Type | Example | Notes |
|---|---|---|
| UUID | 123e4567-e89b-12d3-a456-426614174000 | A universally unique identifier (UUID) is a 128-bit label used for information in computer systems. The term globally unique identifier (GUID) is also used. This is also known as 8-4-4-4-12 format. |
| AAID | cdda802e-fb9c-47ad-9866-0794d394c912 | Google's Android advertising IDs are called AAIDs. They follow the same format as IDFAs, but are all lower case. This is one of the common ID widely used on the AD Tech Industry. |
| IDFA | EA7583CD-A667-48BC-B806-42ECB2B48606 | Apple's iOS advertising IDs are called IDFA and follow this format, all in upper case. |
| Hashed Device ID | af08f98b7000247834265aae2e6a23c1 | Salesforce Audience Studio hashed device IDs are 32 characters long. This is deprecated. |
| Safari (unmanaged) | uap_93e9a58cc03a0e7f45c2cf50ca567a99 | Unmanaged Safari IDs (from event pixels, ad impressions) that are not from a first-party context have uap_ as a prefix. |
| Safari (AS Managed) | kppid_M6ubQ-Og | Audience Studio Managed IDs have kppid_ as a prefix. |
Safari (Client managed) | kppid_k1pid_kppid_i8tlxdjs109 | Client managed first-party IDs in Safari have the following prefixes |
| Firefox (unmanaged) | uapff_93e9a58cc03a0e7f45c2cf50ca567a99 | Unmanaged Firefox IDs (from event pixels, ad impressions) that are not from a first-party context have uapff_ as a prefix. |
| Firefox (AS Managed) | kppidff_abcdefgh | Audience Studio Managed Firefox IDs have kppidff_ as a prefix. |
| Firefox (Client Managed) | k1pidff_cookie_value | Client managed first-party IDs in Firefox have the k1pidff_ prefix.
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