Example costs
OpenAlex data is free; what costs money is usage of the API. This page makes that concrete: the per-operation rate, what a day of free usage buys, and what a few common activities cost. For how billing and plans work, see Pricing; for the API mechanics of sending a key and tracking your usage, see Authentication.
What each operation costs
Tip: Use
per_page=100to load many results per query — it makes your budget go much further.
| Operation | Description | Cost per 1,000 calls |
|---|---|---|
| Get single entity | Retrieve one entity by ID or DOI | Free |
| List + filter | Query and filter entities | $0.10 |
| Search | Full-text keyword search | $1 |
| Semantic search | AI-powered semantic search | $1 |
| Content download | Cached PDF via the content API | $10 |
| Text / Aboutness (deprecated) | Topic classification | $10 |
What your free daily budget buys
Every account gets $1 of usage per day for free. With that $1 you can do a mix of:
| Action | Calls | Results | Example |
|---|---|---|---|
| Get a single entity | Unlimited | Unlimited | Look up a work by DOI |
| List + filter | 10,000 | 1,000,000 | All works from MIT in 2024 |
| Search | 1,000 | 100,000 | Full-text search for “CRISPR” |
| Content download | 100 | 100 PDFs | Download a paper’s full text |
Without a key you get $0.10/day — a tenth of the above, enough to try the API. A free API key gives you 10× that. Need more than $1/day? Paid plans raise your daily budget, and prepaid usage covers anything beyond it.
What common activities cost
| Activity | Endpoint | Calls | Results | Cost |
|---|---|---|---|---|
| Search “climate change AND kelp” | Search | 103 | 10,205 | $0.10 |
| All works from Harvard | List + filter | 8,707 | 870,627 | $0.87 |
| Retrieve works by DOI from a list | Singleton | 1,000,000 | 1,000,000 | Free |
| Daily research (20 searches, 200 filters, 50 lookups) | Mixed | 270 | ~27,000 | $0.04 |
| Download 1,000 PDFs | Content | 1,000 | 1,000 PDFs | $10.00 |
Note: The openalex.org website runs on this same API, so browsing it draws from the same budget (anonymous browsing uses the $0.10/day no-key budget; sign in for $1/day). Viewing a single record’s page (one work, author, source) is free, but a search or a results page loads several billable calls — the list of results plus its facets and charts. So one website search costs more than one API call: a programmatic
/works?search=call is 10 credits, while one search on the website is roughly 18 (the search plus ~5 facet/chart calls). “$1/day ≈ 1,000 searches” holds for direct API calls; browsing the website is about 1.8× costlier per search (closer to ~550/day). A prepaid balance covers anything beyond your daily budget.