If you build a betting app, the first question is which sportsbooks the odds API carries. Pricing pages promise "all the major books". We counted what you get.
We track 45 odds APIs and 135 books. For 10 of the APIs, we call the API with our own key every 3 days and record what comes back. For the other 35, we read the provider's docs. This is the snapshot from 1 November 2026.
The big US books
| Sportsbook | APIs that list it (of 45) | Verified by probe (of 10) |
|---|---|---|
| DraftKings | 23 | 5 |
| FanDuel | 20 | 4 |
| BetMGM | 20 | 5 |
| BetRivers | 19 | 4 |
| theScore Bet | 18 | 5 |
| Caesars | 16 | 4 |
| Fanatics | 16 | 4 |
| Hard Rock Bet | 16 | 4 |
25 APIs list at least one of these 8 books. Only 6 list all 8. If your app needs every one of them, you have a shortlist of 6 before you compare a single price.
One more pattern: every API that lists FanDuel also lists DraftKings. Three list DraftKings without FanDuel.
Prediction markets match the majors
Kalshi ties DraftKings at 23 APIs. Novig, a US sports exchange, is on 18, two more than Caesars. In total, 25 APIs list at least one prediction market or exchange, the same number that list a big US book.
If you devig sportsbook lines against exchange prices, check that one API carries both. Two feeds with different timestamps add error that is hard to spot.
Book count and market depth
The API with the most books in our probes did not return the most markets. One API with about a fifth as many books returned twice as many markets. For a props product, depth can matter more than breadth.
Check your own case
- List the books, leagues and markets you cannot ship without.
- Filter for them in a coverage tool, and prefer verified matches over docs claims.
- Test on a free tier before you pay.
The full tables, the method and a free CSV (CC BY 4.0) are in the Odds API Coverage Report.
