Live Odds Stream: Real-Time Betting Odds with WebSocket
James Whitfield
If you're building a betting app, odds comparison tool, or arbitrage scanner, you need to decide how to fetch odds data. The two main approaches are REST API polling and WebSocket streaming.
REST API vs WebSocket: Which Should You Use?
REST API (Polling)
With a REST API, your app makes repeated HTTP requests to check for odds changes. You control when to fetch data, and each request is independent. This works for occasional lookups but has limitations:
- Updates delayed by your polling interval (typically 2-10 seconds)
- Wastes requests when nothing has changed
- Costs scale with polling frequency and user count
- Can miss rapid odds changes between polls
WebSocket (Live Odds Stream)
With WebSocket, the server pushes updates automatically. The connection stays open and you receive odds changes within milliseconds:
- Updates arrive in 50-200ms (no polling delay)
- Only receive data when odds actually change
- One connection handles unlimited updates
- Never miss an odds movement
What Can You Build with Live Odds Streaming?
Odds comparison platforms - Display odds from multiple bookmakers updating automatically as lines move. Users see current prices without refreshing.
Arbitrage detection - Monitor 250+ bookmakers simultaneously and alert users within milliseconds when pricing inefficiencies appear. Arb opportunities can close within seconds, so speed matters.
Line movement tracking - Watch how odds change over time to identify sharp money moving markets. Historical movement data helps inform betting decisions.
Bet slip validation - Keep bet slips current so users know if their selected odds are still available before placing a bet.
When to Use REST vs WebSocket
Use REST API when:
- Fetching odds once for a bet slip
- Building historical datasets
- Checking odds occasionally (every few minutes)
- Lower request volumes where polling cost is manageable
Use WebSocket when:
- Real-time display matters (odds comparison, live betting)
- Speed is critical (arbitrage, value betting alerts)
- Monitoring many bookmakers simultaneously
- High polling costs would exceed WebSocket pricing
What's Included in the Odds-API WebSocket Stream?
The WebSocket stream includes real-time odds from 250+ bookmakers:
- Sharp bookmakers - SingBet, SBOBet, and other Asian sharp bookmakers
- Exchanges - Betfair Exchange, Betdaq
- Recreational books - Bet365, DraftKings, FanDuel, and 200+ more
- Prediction markets - Polymarket, Kalshi for political and event betting
Filter your stream by sport, league, match, market type, or match status (pre-match, live, or both). One connection can serve your entire application.
Frequently Asked Questions
How fast are WebSocket updates?
Updates typically arrive within 50-200 milliseconds of a bookmaker changing their line. Compare this to REST polling, which adds 2-10 seconds of delay depending on your polling interval.
Can I stream both pre-match and live odds?
Yes. Filter by match status to receive pre-match odds only, live odds only, or both. This lets you build features for both pre-match and in-play betting with one connection.
How many bookmakers can I stream?
The stream includes 250+ bookmakers. Your plan determines how many you can monitor simultaneously: Starter (5 bookmakers), Growth (10), Pro (15). Enterprise plans offer higher limits.
What does WebSocket access cost?
WebSocket is available as an add-on at 2x the REST API rate. While this costs more upfront, it's often more economical than high-frequency polling since one connection delivers unlimited updates.
Get Started with Live Odds Streaming
Enable WebSocket as an add-on through your Odds-API account. Stream odds from 250+ bookmakers across 15+ sports with updates in milliseconds.