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Polygon

Polygon

Upfinancialby Polygon

Polygon.io API provides real-time and historical data for US stocks, forex, and crypto — quotes, candles, earnings, news, technical indicators.

Visit site ↗Health checked 9h ago
Use it when

Ultra-low-latency real-time WebSocket (millisecond ticks)

Watch for

Free tier 5/min (testing only)

First check

Sign up at polygon.io for an API key. GET /v2/aggs/ticker/AAPL/range/1/day/2023-01-01/2024-01-01?apiKey=...

Auth
—
CORS
No
HTTPS
Yes
Signup
?
Latency
458 ms
Protocol
REST, WebSocket
Pricing
—

Uptime · 30-day window

Probes: 1Uptime: 100%Avg latency: 458ms
01

About this API

Polygon.io is the "mid-tier choice" in financial data APIs — much cheaper than institutional-grade Bloomberg/Refinitiv (tens of thousands/month) but a tier above free APIs like Alpha Vantage in data quality and real-time. Covers US stocks, forex, crypto with tick-level WebSocket (real-time, ms latency), minute/hour/day candles, historical backtest data (decades), corporate events (earnings, stock splits, dividends), news sentiment, etc. Used by retail quant traders (individual algo traders) and small hedge funds. Free tier is demo-only (5/min); actual paid from $29/month (basic) to $2000+/month (institutional SIP data). vs. Alpha Vantage, IEX Cloud: Polygon has advantages in low latency and data completeness.

02

What you can build

  • 1Real-time quotes for trading apps
  • 2Algo trading strategy backtesting
  • 3Historical data source for quantitative research
  • 4Financial dashboards and widgets
03

Strengths & limitations

Strengths

  • Ultra-low-latency real-time WebSocket (millisecond ticks)
  • Deep historical data (1980s to present)
  • CSV bulk download for historical data

Limitations

  • Free tier 5/min (testing only)
  • Real trading-grade SIP data costs $99-$2000+/month
04

Example request

Generic template — replace <endpoint> with the real path from the docs.
curl https://polygon.io/<endpoint>
05

Getting started

Sign up at polygon.io for an API key. GET /v2/aggs/ticker/AAPL/range/1/day/2023-01-01/2024-01-01?apiKey=...

06

FAQ

Polygon vs. Alpha Vantage?+

Polygon: higher quality, more stable real-time. Alpha Vantage: more generous free tier. Research: Alpha Vantage. Product-level: Polygon.

Where does crypto data come from?+

Aggregated from major exchanges (Coinbase, Kraken, Binance) to provide best bid/ask.

07

Technical details

CORS: NoHTTPS: YesSignup: ?Open source: No
Auth type
unknown
Pricing
unknown
Protocols
REST, WebSocket
SDKs
python, javascript, go, java, csharp, ruby
Response time
458 ms
Last health check
5/12/2026, 7:38:06 AM
08

Tags

stocksforexcryptofinancerealtime