Review of Indian API Brokers for Algo Trading: Zerodha vs. Dhan vs. Fyers

For an algorithmic trader, the broker is not just a service provider; they are critical infrastructure. A stable API can mean the difference between profit and loss. We stress-tested the three most popular retail APIs in India.

1. Zerodha (Kite Connect)

The gold standard. Kite Connect offers the most stable and well-documented API in the ecosystem.

• Pros: Extremely reliable, massive community support, clean documentation.
• Cons: Cost (₹2000/month for API + ₹2000 for historical data). Rate limit of 3 requests/second is strict.
• Verdict: Best for serious retail traders who value stability over cost.

2. Dhan (DhanHQ)

The challenger. Dhan has aggressively targeted super-traders with their "Superfast" API.

• Pros: Free API usage. Higher rate limits than Zerodha. Focused heavily on tech-first features (TradingView integration).
• Cons: Newer infrastructure, occasional teething issues with websocket stability during high volatility events.
• Verdict: Best for high-frequency strategies where cost is a major factor.

3. Fyers (Fyers API V3)

The innovator. Fyers was one of the first to offer a completely free API.

• Pros: Free API. Good historical data indexing. V3 API is significantly faster than previous versions.
• Cons: Documentation can be sparse in areas. Token management flow is slightly more complex.
• Verdict: A solid middle ground choice.

Speed Test Results (Round Trip Latency)

Note: Latency measured from AWS Mumbai region.

Conclusion

If you are running a low-frequency trend following system, any of these will work. For HFT-lite strategies, Dhan's free API and speed offer an edge, but Zerodha's reliability is unmatched for larger capital deployment.