10 Best Free Stock Market Data APIs – Try NOW!
Stock market data APIs are the lifeline of anyone building tools for the financial world. Whether you are an investor tracking your portfolio, an analyst building valuation models, a trader trying to automate strategies, a bot builder running signals or an app developer creating a dashboard, everything depends on how good your data feed is.
Prices, fundamentals, financial statements, corporate actions, earnings dates, real time quotes and even market news all come from data APIs. Without them you are just guessing and hoping the market plays nice.
The tough part is that most reliable stock data sources sit behind paywalls. Real time quotes often cost extra.
Historical intraday data is rarely free. Fundamentals and financial statements usually come with usage caps. Many APIs limit how many calls you can make per minute and some restrict high frequency features to paid tiers only.
That makes choosing the right free API more than just a convenience. It decides whether your tool runs smoothly or breaks the moment you scale it.
This article focuses on the ten best free stock market data APIs that give you surprisingly strong features without forcing you into a subscription on day one. Each one comes with strengths, limitations and specific use cases.
I will explain what they offer, what makes them stand out and when they are the right choice. This is the part where Altie stops you from wasting weeks testing APIs that look good on paper but collapse under real usage.
What to Look for in a Free Stock Market Data API
Before you choose any API, you need to know what matters. A free API is only useful if it gives you the kind of information your project depends on. Here are the factors that separate the good from the useless.
Data types available. The first thing you check is whether the API gives you the data your project needs. This includes real time or near real time price quotes, historical OHLCV for charting, corporate actions like dividends and splits, company fundamentals, earnings reports and ideally some form of market news or sentiment data.
Coverage. Not all APIs support all markets. Some only cover US exchanges like NASDAQ and NYSE. Others offer global coverage including Europe, India, Japan and emerging markets. Your product may need specific exchanges, so you cannot assume everything is included by default.
Rate limits. Free plans often limit how many calls you can make per minute, hour or day. If your system hits the API frequently, those limits matter. You also need to check if they restrict concurrent connections or throttle if you exceed a certain threshold.
Feature access. Some APIs offer both REST endpoints and WebSocket streams but keep the real time WebSockets behind a paywall. Others limit bulk downloads or hide premium data until you upgrade. You need to check which features are actually included in the free tier before you build around them.
Documentation and ease of use. Strong docs make development faster. Clear endpoints, example requests, understandable responses and sandboxes for testing help you avoid endless debugging. Weak documentation creates friction, delays development and increases mistakes.
Reliability and uptime. You cannot afford an API that fails during market hours. Good APIs maintain consistent uptime, return accurate real time prices and include historical data without missing candles. Bad ones introduce delays, serve incomplete datasets or break under load.
The 10 Best Free Stock Market Data APIs
Alpha Vantage – Best Free Stock Market Data API
Description: Alpha Vantage is one of the most popular free stock market APIs because it delivers time series data, technical indicators and multi-asset support without making you jump through hoops. It is beginner friendly, well documented and perfect for dashboards, prototypes and lightweight bots.
USP: A wide range of technical indicators and time series data available completely free.
Key Features:
- Intraday and historical OHLCV
- Technical indicators like RSI, MACD and SMA
- Global stock coverage
- Forex and crypto data included
- Straightforward REST endpoints
Why it is the best by Altie: This is the API I recommend to anyone starting out. It is simple, powerful enough and does not hide the essentials behind paywalls. Perfect for dashboards and market visualizations.
Finnhub – 2nd Best Free Stock Market Data API
Description: Finnhub provides real time stock quotes and a wide range of financial data including fundamentals, company filings, earnings calendars and news. It is built for developers who want deeper financial context, not just price charts.
USP: Rich fundamental data and real time quotes in the free tier.
Key Features:
- US and global equity coverage
- Earnings data and transcripts
- Company fundamentals
- Real time price feeds
- News and sentiment
Why it is the best by Altie: If you are doing serious research or want an API that goes beyond raw prices, Finnhub gives you the depth. It is ideal for analysts and financial modelers.
Twelve Data – 3rd Best Free Stock Market Data API
Description: Twelve Data focuses on global market coverage and ease of integration. It supports stocks, forex, crypto and ETFs and is known for clean data, clear documentation and strong multi-region support.
USP: Excellent global exchange coverage across many regions.
Key Features:
- Real time and historical data
- Technical indicators
- Multiple asset classes
- WebSocket support
- JSON and CSV output formats
Why it is the best by Altie: If your project needs international data, this is one of the best free options. It is also developer friendly, which makes building global dashboards much easier.
Marketstack – 4th Best Free Stock Market Data API
Description: Marketstack offers real time and historical market data from dozens of global exchanges. It is simple, fast and ideal for commercial or personal projects that need broad coverage without complex integration.
USP: Global exchange coverage in a lightweight, easy to use format.
Key Features:
- Real time and intraday prices
- Historical EOD data
- Supports more than 70 global exchanges
- Clean API structure
- Good documentation
Why it is the best by Altie: For dashboards or apps that need international pricing data without a huge learning curve, Marketstack delivers exactly what you need.
Financial Modeling Prep (FMP) – 5th Best Free Stock Market Data API
Description: FMP specializes in financial statements, fundamentals, balance sheets, cash flows and company profiles. It is the go-to API if you are building valuation tools, screening systems or deep research dashboards.
USP: Comprehensive financial fundamentals and statements for free.
Key Features:
- Income statements and balance sheets
- Historical fundamentals
- Stock prices and market profiles
- Company metrics and ratios
- SEC filings
Why it is the best by Altie: If you want to build something analytical, fundamental or research heavy, FMP saves you days of manual data scraping. It is a top choice for analysts.
EODHD – 6th Best Free Stock Market Data API
Description: EODHD provides end of day and intraday stock data for global markets along with fundamentals, splits, dividends and even options chains in some tiers. It is reliable and well structured.
USP: Strong mix of price data, fundamentals and corporate actions.
Key Features:
- Global stock coverage
- OHLCV historical data
- Corporate actions
- Fundamentals
- Dividends and splits
Why it is the best by Altie: This API hits the balance between breadth and depth. It is excellent for global portfolios and long term analysis tools.
IEX Cloud – 7th Best Free Stock Market Data API
Description: IEX Cloud offers high quality US market data via the IEX exchange along with additional datasets. The free tier is limited but still useful for prototyping or learning.
USP: Reliable US stock data from a reputable exchange source.
Key Features:
- US real time quotes
- Historical prices
- Basic fundamentals
- News endpoints
- Developer friendly documentation
Why it is the best by Altie: If you only need US market data and you care about reliability, IEX Cloud gives you a clean, accurate feed.
Polygon – 8th Best Free Stock Market Data API
Description: Polygon offers institutional-grade data with real time streams, tick-level quotes and high performance endpoints. It is built for traders, bots and high frequency use cases.
USP: High speed real time data and WebSocket streams ideal for trading bots.
Key Features:
- Real time quotes
- Tick-level data
- WebSocket streaming
- Historical trades
- News and aggregates
Why it is the best by Altie: If you are building a bot or a trading system that depends on fast data, Polygon is one of the strongest free options available.
Alpaca Markets – 9th Best Free Stock Market Data API
Description: Alpaca is known for its trading API but it also provides market data, including real time and historical prices, inside its free data plan. It is convenient if your project involves both data and execution.
USP: Data plus trading capabilities integrated in one platform.
Key Features:
- US stock data
- Real time and historical feeds
- Paper trading
- Order execution API
- WebSockets
Why it is the best by Altie: If you want to move from data analysis to actual trading, Alpaca lets you do everything in the same environment without switching providers.
Yahoo Finance (via community APIs such as yfinance) – 10th Best Free Stock Market Data API
Description: Yahoo Finance is not an official API provider, but its data can be accessed through community libraries like yfinance. It gives you reliable historical data, dividends and basic fundamentals.
USP: Fast and simple access to historical data for research or prototyping.
Key Features:
- Historical OHLCV
- Dividends and splits
- Basic fundamentals
- ETF and index data
- Easy integration with Python
Why it is the best by Altie: For quick research projects, machine learning experiments or academic use, Yahoo Finance data is more than enough and extremely easy to work with.
Best Picks for Different Users
Different tools require different types of data. One API cannot do everything equally well, so here is the clean recommendation matrix to help you pick the right one without second-guessing yourself.
For bots: Polygon, Alpaca, IEX Cloud
Bots depend on speed, real time quotes and stable WebSocket streams. Polygon delivers fast tick-level data, Alpaca offers real time feeds plus execution and IEX Cloud provides reliable US market data.
For dashboards: Marketstack, Alpha Vantage
Dashboards need wide coverage and simple endpoints. Marketstack offers global data with minimal friction and Alpha Vantage provides clean time series that fit perfectly into charting tools.
For deep financial research: Financial Modeling Prep, Finnhub
Research requires fundamentals, filings, earnings reports and financial statements. FMP specializes in structured financial data and Finnhub adds transcripts, news and sentiment.
For global coverage projects: Twelve Data, EODHD
If your app needs data from more than just US markets, these two give you reliable access to multiple global exchanges with clear documentation.
For historical analysis: Alpha Vantage, Yahoo Finance
Historical backtesting and model training rely on long, consistent datasets. Alpha Vantage offers structured time series and Yahoo Finance is exceptionally easy for researchers using tools like Python.
How to Choose the Right Free API for Your Project
To avoid building your entire system around the wrong API, you need a simple decision framework. Here is the Altie-approved checklist that keeps you from hitting a dead end halfway through development.
Define your use case first; Every project has a core dependency. Bots require real time speed. Dashboards need broad data. ML models need bulk history. Research tools need fundamentals. Define the mission before picking the API.
Determine the type of data needed; List exactly what you need: intraday OHLCV, real time quotes, fundamentals, dividends, analyst ratings or earnings dates. Once you know the dataset, you can match the API accordingly.
Check rate limits before building; Many free APIs look promising until you realize the limits are too low for your system. Always confirm calls per minute, per hour and per day. Check concurrency restrictions as well.
Select between REST and WebSockets; REST is fine for static or periodic updates. Bots or streaming dashboards need WebSockets. Some APIs only offer WebSockets through paid tiers, so verify availability early.
Evaluate documentation quality; Good docs accelerate development. They show clear examples, response formats and usage patterns. Poor docs slow everything down. If you cannot understand the API quickly, it will be a constant bottleneck.
Look for scalability beyond the free tier; Your system may grow. Check whether the paid plans are reasonable and whether upgrading later makes sense. It is better to scale within a provider than to migrate hundreds of lines of code to a new one.
Conclusion – Best Free Stock Market Data APIs
Free stock market data APIs are more powerful today than ever before.
They give investors, analysts, traders and developers enough data to build real tools without paying upfront. Whether you need historical time series for analysis, real time quotes for bots, fundamentals for research or global coverage for dashboards, there is a free API that matches your needs.
The smart approach is to test multiple APIs rather than relying on just one. Each provider excels in a different area and combining two or three is often the best way to improve accuracy and reliability.
s your project grows, you can always upgrade to paid tiers or consolidate providers, but free APIs are more than enough for early stage development.
Altie’s take is simple. Start with free tools, get your system running, gather real results and only upgrade when the project proves it is worth investing in.
Free APIs give you everything you need to build, experiment and learn without risking budget or momentum.