Published 2026-06-18 · reference numbers, verify before budgeting
If you're building a finance dashboard, a backtester, or a trading bot, the market-data API is the bill you forget to budget for. The free tiers look generous until your project needs real-time quotes — then the price jumps, and one detail catches almost everyone out: several providers bill per asset class, so "stocks + options + crypto" can be three subscriptions, not one. We compared the three most common picks — Alpha Vantage, Finnhub and Polygon.io — on what they actually cost and what you give up at each tier.
All three have a no-credit-card free tier, but they're wildly different in shape. The number that matters isn't "is it free" — it's how many calls per minute and how fresh the data is:
| Provider | Free rate limit | Data freshness | Best free use |
|---|---|---|---|
| Finnhub | ~60 calls / min | real-time (US) | live dashboards, quotes |
| Alpha Vantage | ~25 / day, 5 / min | EOD / delayed | cached backtests, indicators |
| Polygon.io | 5 calls / min | EOD & 15-min delayed | dev sandbox, history |
The headline: Finnhub's free tier is in a different league for live data — 60 calls a minute with real-time US quotes is enough to run a small dashboard or a hobby bot without paying a cent. Alpha Vantage gives you far more types of data (50+ technical indicators, fundamentals, FX) but a punishing ~25 requests per day, so it only works if you cache aggressively. Polygon's free tier is deliberately a sandbox: 5 calls/min and delayed data, meant for testing the API before you upgrade. The catch on all three free tiers is licensing — Finnhub's is explicitly non-commercial, so the moment you monetise, you're on a paid plan.
Once you need real-time data, commercial rights, or more throughput, here's roughly where entry-level paid plans land in 2026:
| Provider | Entry paid plan | What it unlocks | Billing quirk |
|---|---|---|---|
| Polygon.io | ~$29 / mo | unlimited calls, 5yr history | per asset class |
| Finnhub | ~$50 / mo | higher limits, more endpoints | premium data as add-ons |
| Alpha Vantage | ~$50 / mo | 75 calls/min | by requests-per-minute |
Polygon.io has the cheapest sticker entry at ~$29/month — but read the billing quirk column. Polygon prices per asset class: stocks, options, and forex/crypto are separate subscriptions. A bot that trades both stocks and options is two Polygon plans, so the "$29" can quietly become $58+. Finnhub bundles more into one plan but sells institutional fundamentals and global data as add-ons, so two "Premium" bills can differ a lot. Alpha Vantage is the most predictable: a flat fee for a requests-per-minute ceiling, no per-call or per-asset surprises.
The fastest way to outgrow a free tier — or blow a rate limit on a paid one — is live polling when you don't need it. If your dashboard refreshes 20 tickers every 10 seconds, that's 120 calls/minute; you've blown past Finnhub's free 60 and you're paying for throughput you don't use. Most finance apps don't actually need second-by-second data: a 1–5 minute cache, or a websocket for the handful of symbols a user is actually watching, cuts call volume by 10–50× and keeps you on a cheaper tier. The pattern is the same lesson as the rest of API budgeting — usage shape decides the bill far more than the sticker price, exactly like the hidden costs that double your AI and SMS bills.
For most builders the honest answer is: start on Finnhub's free tier, cache hard, and only pay when you have a real reason (commercial use, real-time at scale, or options/tick data). The free tiers are good enough to ship an MVP, and the cheapest sticker price — Polygon's $29 — isn't necessarily the cheapest bill once per-asset-class billing kicks in. As always, model your real call pattern before you commit to a plan.
Compare the guides: Finnhub · Alpha Vantage · Polygon.io · all market data APIs.
Figures are reference estimates (June 2026) and change frequently — plans, rate limits and add-on data feeds vary. Always confirm on each provider's official pricing page before budgeting.