Two different performance questions
"Is the API fast?" is really two separate questions: how quickly does the API respond to a single request (latency), and how quickly does new match data reach your application after it happens on court (freshness). They're solved differently - REST for the former, WebSocket for the latter.
Request latency (REST)
For REST endpoints - fixtures, standings, players, H2H, odds - the API is built to respond quickly to structured queries so you can render a page or populate a dashboard without a noticeable wait. Because this data doesn't change second by second, it's also a good candidate for caching on your side: cache fixtures and standings for a few minutes rather than requesting them on every page load.
Live data freshness (WebSocket)
For in-progress matches, freshness matters more than raw request latency. The WebSocket feed pushes score and point updates to connected clients as they happen, which avoids the inherent lag of polling a REST endpoint every few seconds. If your product shows live scores, this is the transport to build on - read more in REST vs WebSocket for live tennis data.
Designing your app around real-world conditions
A few practical guidelines that apply to any production integration, tennis-specific or not:
- Cache what doesn't change often. Player profiles, tournament metadata, and historical results are stable - cache them aggressively.
- Use WebSocket for anything "live". Polling REST endpoints for live scores wastes requests and adds latency compared to a persistent connection.
- Handle reconnects gracefully. Any WebSocket client should reconnect automatically on drop - normal on mobile networks - rather than surfacing a stale score to the user.
- Rate-limit your own polling. If you do poll REST for near-live use cases, space requests out sensibly rather than hammering the endpoint every second.
Reliability in practice
API Tennis is used in production by betting platforms, media sites and fantasy sports apps where an outage or stale score is directly visible to end users - which is why uptime and data accuracy are treated as the core product, not an afterthought. If you're evaluating the API for a production workload, the best test is the one you can run yourself: follow the 5-minute quickstart and watch a live match update in real time.
Frequently asked questions
How fast does the livescore feed update?
Livescore data is refreshed continuously as points are played, and the WebSocket feed pushes updates to connected clients as soon as they are recorded, without the client needing to poll.
Should I use REST or WebSocket for live scores?
Use the WebSocket feed for live, in-progress matches where you need point-by-point updates, and REST for fixtures, results, and any data that does not need to change every few seconds. See our REST vs WebSocket comparison for details.
What happens if a request fails?
Build your integration to retry failed requests with backoff, same as you would for any external API. For live data, prefer the WebSocket connection, which reconnects automatically and avoids the failure modes of repeated polling.