Polygon.io
Institutional-grade financial data API with real-time WebSocket streaming, tick-level data, and broad market coverage.
Quick Facts
- Starting Price
- Free
- Free Tier
- Yes
- Founded
- 2016
- Company
- Polygon.io Inc.
Polygon.io Overview
Polygon.io provides institutional-grade financial data through a modern REST and WebSocket API, covering stocks, options, forex, and crypto markets. The platform is known for its low-latency real-time data, tick-level historical data, and comprehensive market coverage.
Unlike Alpha Vantage which focuses on simplicity, Polygon.io targets more demanding use cases with WebSocket streaming for real-time data, millisecond-precision timestamps, and aggregated bar data from 1-second to daily intervals. The API also provides reference data, corporate actions, financial statements, and SEC filings.
The free tier is more generous than most competitors at 5 API requests per minute with delayed data. Paid plans start at $199/month for real-time data access, making it a serious investment but one that provides genuinely institutional-quality data feeds.
Polygon.io Pricing
Basic (Free)
- ✓ 5 requests/minute
- ✓ Delayed data
- ✓ End-of-day data
- ✓ Limited endpoints
Starter
- ✓ Unlimited requests
- ✓ All data endpoints
- ✓ Delayed data
- ✓ Historical data
Developer
- ✓ All Starter features
- ✓ Real-time WebSocket
- ✓ Tick data
- ✓ Options data
Advanced
- ✓ All Developer features
- ✓ Unlimited real-time
- ✓ Priority support
- ✓ SLA guarantee
Features
Pros & Cons
Pros
- + WebSocket streaming for real-time data
- + Tick-level historical precision
- + Generous free tier at 5 req/min
- + Institutional-grade data quality
Cons
- - Real-time data requires $199/mo plan
- - Can be complex for non-developers
- - Options data costs extra
- - Less beginner-friendly than Alpha Vantage
Rating Breakdown
Overall Rating
Key Takeaways
- ✓ WebSocket streaming for real-time data
- ✓ Tick-level historical precision
- ✓ Generous free tier at 5 req/min
- ✓ Institutional-grade data quality
- ★ Rated 4.4/5 — best for developers, algorithmic traders, fintech builders
- $ Free tier available
Summary
Institutional-grade financial data API with real-time WebSocket streaming, tick-level data, and broad market coverage. Polygon.io offers a free tier, with paid plans from $29/month. Best suited for developers, algorithmic traders, and fintech builders.
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