Subfields Overview
Subfields are the third level of the OpenAlex topic hierarchy. There are 254 subfields spread across 26 fields. Each subfield contains multiple topics.
The topic hierarchy is: Domain → Field → Subfield → Topic
Filter, sort, and group_by fields
The API supports filtering, sorting, and grouping on subfields fields. See Filtering, Sorting, and Grouping for syntax.
Fields marked (deprecated) are .search filters — use the search parameter instead.
| Field | Sort | Group_by | Filter |
|---|---|---|---|
cited_by_count |
✓ | ✓ | ✓ |
default.search (deprecated) |
✓ | ||
display_name |
✓ | ✓ | |
display_name.search (deprecated) |
✓ | ||
domain.id |
✓ | ✓ | ✓ |
field.id |
✓ | ✓ | ✓ |
from_created_date |
✓ | ✓ | |
id |
✓ | ✓ | ✓ |
topics.id |
✓ | ✓ | ✓ |
works_count |
✓ | ✓ | ✓ |