Best Paper Trading API Alternatives
We built this guide to help developers compare popular paper trading APIs across the criteria that matter: real-time data, realistic fills, language support, limits and pricing.
TL;DR Summary
- Realistic fills and slippage modeling change strategy results — avoid fantasy fills.
- Stable streaming (WebSockets/SSE) is critical for live dashboards and bots.
- Examples for Python and Node cut onboarding time from hours to minutes.
| Provider | Realistic Fills | Streaming | Python / Node | Notes |
|---|---|---|---|---|
| Paper | NBBO, partials, slippage, latency | WebSockets + SSE | Examples for both | Free tier to start |
| Competitor A | Basic fills | WebSockets | Python only | Limited docs |
| Competitor B | Instant fills | Polling | Node only | No streaming |
FAQ
What makes a good paper trading API?
Realistic fills, stable streaming, clear docs, and transparent limits. Support for Python and Node helps onboarding.
Why choose Paper?
Realistic NBBO fills, partials, latency, plus WebSockets/SSE and language examples. Purpose-built for developers.