Polygon.io vs Twelve Data
Category: Finance · Updated June 2026
Both Polygon.io (Unlimited delayed data, free key, no credit card) and Twelve Data (800 calls/day, free key, no credit card) offer comparable free tiers. Twelve Data currently leads on reliability with 100% uptime vs Polygon.io's 0% uptime over the last 30 days. Pick Twelve Data for hobby projects; consider Polygon.io if you need its specific feature set.
Side-by-side comparison
Polygon.io
Real-time and historical stock, options, forex, and crypto market data with WebSocket streaming support.
| Status | 🔴 Offline |
| 30-day uptime | 0% |
| Response time | 694 ms |
| Free tier | Unlimited delayed data, free key, no credit card |
| Auth | API key |
| Tier score | 0.7 — free key, no card |
Twelve Data
Financial market data API covering stocks, forex, ETFs, and mutual funds with real-time and historical data.
| Status | 🟢 Online |
| 30-day uptime | 100% |
| Response time | 376 ms |
| Free tier | 800 calls/day, free key, no credit card |
| Auth | API key |
| Tier score | 0.7 — free key, no card |
Which to choose?
- Pick Polygon.io if…its feature set (Unlimited delayed data, free key, no credit card) fits your request volume and you're comfortable with a free API key.
- Pick Twelve Data if…reliability matters most — it shows higher uptime in our 30-day tracking. Good for production workloads in the finance space.
- Use both if…you need redundancy or coverage across different data providers. Both use API keys, so rotating between them is straightforward for failover.
Or use these alternatives
Other top-ranked Finance APIs you might consider:
- European Central Bank Rates — 🟢 Online · Unlimited, no key, no credit card
- Fixer.io — 🟢 Online · 100 calls/month, EUR base only, free key, no CC
Frequently Asked Questions
Is Polygon.io or Twelve Data more reliable?
Based on our 30-day tracking, Twelve Data is more reliable with 100% uptime compared to Polygon.io's 0%. Both are measured from the same automated hourly checks — no self-reported data.
Which one has a more generous free tier — Polygon.io or Twelve Data?
Both have comparable free tiers. Polygon.io offers Unlimited delayed data, free key, no credit card and Twelve Data offers 800 calls/day, free key, no credit card. The right choice depends on your specific call volume and auth preferences.
Can I use Polygon.io and Twelve Data together?
Yes. Both require an API key, so you can register for both free accounts and implement a simple fallback: try Polygon.io first and fall back to Twelve Data if you hit rate limits or encounter downtime. This is a common pattern for production resilience.
What's the cheapest paid alternative if both Polygon.io and Twelve Data fail?
If you need a paid fallback, Polygon Starter is one of the more affordable options (from $29/mo). You can find the full list of paid alternatives on each API's detail page. Paid tiers typically offer SLA guarantees, higher rate limits, and dedicated support.
See full profiles: Polygon.io · Twelve Data · All Finance APIs