Languages
A language is the language of a work’s metadata — its title and abstract — identified by a two-letter ISO 639-1 code: en for English, es for Spanish, zh for Chinese. Languages are a vocabulary: a fixed, standardized list OpenAlex attaches handles to rather than inventing. Each work carries a single language, auto-detected with langdetect — so a language value reflects the metadata language, not necessarily the full text, and is unset when there aren’t enough words to guess reliably. A language’s OpenAlex ID looks like https://openalex.org/languages/en; fetch one at api.openalex.org/languages/en.
How it’s made
We don’t build the list — we adopt ISO 639-1, the standard two-letter language codes, and add live counts of the works detected in each. Detection is per-work and automatic (see the work language field). There are 180 languages.
Values
The full list of 180 languages is at api.openalex.org/languages — page through with per_page=200 to pull every one. A sample of the largest by works count:
| Code | Language |
|---|---|
en |
English |
de |
German |
es |
Spanish |
fr |
French |
ja |
Japanese |
pt |
Portuguese |
zh |
Chinese |
ru |
Russian |
it |
Italian |
id |
Indonesian |
ko |
Korean |
nl |
Dutch |
Attributes
The top-level fields on a language object. Attributes shared with other entities (id, display_name, works_count, cited_by_count, created_date, updated_date) are documented once on Common attributes.
id
String. The OpenAlex ID for this language, e.g. https://openalex.org/languages/en. The final path segment is the ISO 639-1 code. See Common attributes.
display_name
String. The language’s English name, e.g. English. See Common attributes.
works_count
Integer. How many works OpenAlex has detected in this language. See Common attributes.
cited_by_count
Integer. Total citations across those works. See Common attributes.
works_api_url
String. A ready-made Works API URL for every work in this language (filter=language:<CODE>).
created_date
String. When the language record was added to OpenAlex (YYYY-MM-DD). See Common attributes.
updated_date
String. When the language record last changed. See Common attributes.
In the API
The Languages endpoint is at api.openalex.org/languages. Fetch one by code — /languages/en — or list them all.
Languages are most useful as a filter on works: filter=language:fr returns works whose metadata is in French, and group_by=language breaks any result set down by language. See Filtering for the full syntax and the endpoints index for every endpoint. See also the work language field for how the value is assigned.