Ahrefs API: the Difference Between API v2 and UI Data

Ahrefs support has confirmed that API v2 uses an outdated database, while the web version uses a newer database.

Key Differences:

1. Data Sources:

• API v2/Integrations API: Uses data from the legacy database.
• UI: Utilizes data from the newer, more accurate database.

2. Accuracy:

• The new database in the UI provides more accurate data compared to the legacy database in API v2.
• The newer database typically shows fewer backlinks, referring domains, and organic keywords.

Reasons for Data Discrepancies:

• Backlink Recrawling:

  • The newer database automatically filters out backlinks that have not been recrawled for more than 6 months.
•  Unique Organic Keywords:
  • Only unique organic keywords are counted in the newer database.
  • The UI reports the best URL of the selected domain for each keyword (if multiple URLs rank for the same keyword).

This information is new to us, and while we knew that API v2 was outdated, it wasn't clear that it was using an older database. As a result, the data in the Checker can now only be used as an approximation and will not match the web interface exactly.