TRADINGDATACOMPARE
LIVE · 2026-05-27

Best for
WebSocket Streaming.

Real-time WebSocket APIs for streaming quotes, trades, and aggregates with low latency.

Ranked · Top 5

#1
Polygon.io (now Massive) TOP PICK FREE TIER

Real-time and historical stock, options, forex, and crypto data — rebranded to Massive in 2026

FROM $0/mo API REST · WebSocket · SDK SDK Python · JavaScript · Go
REVIEW →
#2
Databento FREE TIER

Institutional-grade tick data with pay-as-you-go pricing

FROM From $0 API REST · WebSocket · SDK SDK Python · Rust · C++
REVIEW →
#3
Alpaca FREE TIER

Commission-free broker API with built-in market data

FROM $0/mo API REST · WebSocket · SDK SDK Python · JavaScript · Go
REVIEW →
#4
Finnhub FREE TIER

Free real-time stock API with news, sentiment, and fundamentals

FROM $0/mo API REST · WebSocket SDK Python · JavaScript · Go
REVIEW →
#5
AllTick FREE TIER

Multi-market real-time data API covering US, HK, CN stocks plus forex and crypto with broad asset breadth

FROM $0/mo API REST · WebSocket SDK Python · JavaScript · C#
REVIEW →

Cross-Reference

Polygon.io (now Massive) vs Databento Polygon.io (now Massive) vs Alpaca Databento vs Alpaca Databento vs Finnhub Alpaca vs Finnhub Alpaca vs AllTick Finnhub vs AllTick

Other Use Cases

Best for Algo TradingBest for Crypto TradingBest for Forex TradingBest for BacktestingBest for Quant ResearchBest for Fintech App DevelopmentBest for BeginnersBest for Options TradingBest for Real-Time Market DataBest for Global EquitiesBest for Python DevelopersBest for JavaScript / Node.js DevelopersBest for Deep Historical DataBest for Free Tier OnlyBest for Budget Under $30/moBest for Institutional / EnterpriseBest for Active TradersBest for Options Trading (Brokers)Best for Global Multi-Asset BrokersBest for Brokers with API AccessBest for Prop Firms for BeginnersBest for Prop Firms for ForexBest for 1-Step Prop Firm ChallengesBest for Highest Prop Firm Profit Splits