Best Free Finance & Stock Market APIs for Developers

Building a finance app, portfolio tracker, or trading dashboard? You'll need market data — and fortunately, several APIs offer it for free. Here are the best options, what they provide, and how they compare.

1. Alpha Vantage

Auth: API Key (free) | Free tier: 25 requests/day | Data: Stocks, forex, crypto

Alpha Vantage is one of the most comprehensive free financial data APIs. It covers US and international stocks, forex pairs, and major cryptocurrencies with both real-time and historical data.

What you get:

• Real-time and historical stock prices (daily, weekly, monthly)
• Intraday data at 1-minute to 60-minute intervals
• Technical indicators (SMA, EMA, RSI, MACD, and 50+ more)
• Forex exchange rates
• Cryptocurrency prices
• Fundamental data (earnings, balance sheets, income statements)

Best for: Serious finance projects that need technical analysis and fundamental data. The data depth is impressive for a free API.

Limitations: The 25 requests/day limit on the free tier is tight. You'll need to cache aggressively or upgrade for anything beyond a simple dashboard.

2. Twelve Data

Auth: API Key (free) | Free tier: 800 requests/day | Data: Stocks, forex, crypto, ETFs

Twelve Data offers a more generous free tier than Alpha Vantage while covering a similar range of data. The API design is clean and the documentation is excellent.

What you get:

• Real-time and historical prices for 100,000+ instruments
• Technical indicators
• WebSocket streaming for real-time updates
• Forex and crypto data

Best for: Projects that need more daily requests than Alpha Vantage allows. The WebSocket support is a bonus for real-time dashboards.

3. CoinGecko

Auth: None (or API Key for higher limits) | Free tier: 10-30 calls/minute | Data: Cryptocurrency only

If you're building anything crypto-related, CoinGecko is the go-to API. It covers thousands of coins and tokens with rich market data.

What you get:

• Current prices for 13,000+ cryptocurrencies
• Market cap, volume, and price change data
• Historical price charts
• Exchange and trading pair information
• Trending coins and market overview

Best for: Crypto portfolio trackers, price alerts, and market dashboards.

4. Exchange Rates API

Auth: None or API Key | Free tier: Varies | Data: Currency exchange rates

Several free APIs provide currency exchange rates. The most popular options include exchangerate.host and Open Exchange Rates. These are essential for international e-commerce and travel apps.

What you get:

• Real-time exchange rates for 150+ currencies
• Historical rates for date-based conversions
• Currency conversion endpoints

Best for: E-commerce price conversion, travel budget calculators, and international financial tools.

5. Yahoo Finance (Unofficial)

Auth: None | Data: Stocks, ETFs, mutual funds

Yahoo Finance doesn't offer an official API, but several community-maintained wrappers exist. These are popular for personal projects, though they carry the risk of breaking changes since they're unofficial.

Best for: Quick personal projects and learning. Not recommended for production apps due to reliability concerns.

Limitations: No official support, may break without notice, potential terms-of-service concerns.

Tips for building with finance APIs

• Cache everything. Stock prices don't change every millisecond for most use cases. Cache responses for 1-5 minutes to stay within rate limits.
• Understand market hours. US stock markets are open 9:30 AM - 4:00 PM ET, Monday-Friday. Outside those hours, prices won't change (except for pre/post-market data).
• Handle missing data. Not every stock or time period has complete data. Your app should handle gaps gracefully.
• Display timestamps. Financial data is time-sensitive. Always show when data was last updated.
• Add disclaimers. Free APIs may have delayed data (15-20 minutes). If your app displays prices, note that they may not be real-time.

Browse all finance APIs in our Finance category and crypto APIs in our Blockchain category.