Polygon.io
Real-time and historical stock, options, forex, and crypto market data with WebSocket streaming support.
🔴 Offline · 694 ms
0%
Unlimited delayed data, free key, no credit card
API key
Free alternatives (live ranking)
- European Central Bank Rates — 🟢 Online · Unlimited, no key, no credit card
- Twelve Data — 🟢 Online · 800 calls/day, free key, no credit card
- Fixer.io — 🟢 Online · 100 calls/month, EUR base only, free key, no CC
Compare Polygon.io with…
- Polygon.io vs European Central Bank Rates — Unlimited, no key, no credit card
- Polygon.io vs Twelve Data — 800 calls/day, free key, no credit card
- Polygon.io vs Fixer.io — 100 calls/month, EUR base only, free key, no CC
Paid alternatives
- Polygon Starter — from $29/mo
Frequently Asked Questions
Does Polygon.io require an API key?
Yes, Polygon.io requires a free API key. You can sign up via https://polygon.io/docs/stocks.
What is Polygon.io's free tier?
Unlimited delayed data, free key, no credit card
Is Polygon.io currently online?
We check Polygon.io every hour. The current status is shown at the top of this page. You can also see the 30-day uptime history in the chart above.
Implementation notes
When to use Polygon.io
Polygon.io is the right choice when you need real-time WebSocket streaming of US market data with no key or a free key. Its public free tier provides unlimited delayed data (15 minutes for stocks) with REST and WebSocket access — the WebSocket support alone distinguishes it from most free competitors.
Common pitfalls
- The free tier provides data with a 15-minute delay for US stocks. Real-time data requires a paid plan ($29/month). This is clearly documented but easy to overlook when building dashboards — the API response includes a `t` (timestamp) field that confirms the data time.
- Polygon's REST API has two base URL patterns: `api.polygon.io` for most endpoints and `api.polygon.io/v2` for aggregates. The aggregates endpoint (`/v2/aggs/ticker/{symbol}/range/...`) is the primary one for OHLCV bars and has a different URL structure than current price endpoints.
- Options and forex data on the free tier are similarly delayed. The Crypto endpoints (via `/v2/aggs/ticker/X:{crypto}/...`) use a different symbol format with the `X:` prefix.
- WebSocket connections on the free tier are limited to the delayed feed. Connecting to `wss://delayed.polygon.io` requires authentication via `{'action':'auth','params':'YOUR_KEY'}` as the first message after connecting.
Quick start (bash)
curl "https://api.polygon.io/v2/aggs/ticker/AAPL/range/1/day/2024-01-01/2024-01-31?adjusted=true&sort=asc&apiKey=YOUR_KEY"Embed this badge
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Markdown
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