Research

Top Free APIs Every Developer Should Know in 2024

Discover the best free-to-use APIs for crypto, AI, and data apps. See which trusted APIs developers rely on for robust features, reliability, and easy integration.
Token Metrics Team
5
MIN

APIs are the silent workhorses powering today’s most innovative software. Whether you’re a crypto enthusiast automating portfolio analysis, or a web developer looking to enrich your app with real-time data, the right free API can supercharge your project—and your productivity. But with thousands out there, which free APIs truly stand out for reliability, ease of use, and breadth of features?

Why Free APIs Matter for Developers and Innovators

APIs—Application Programming Interfaces—allow applications to seamlessly interact, share insights, and build on each other's strengths. The best free-to-use APIs democratize access to powerful datasets, functionalities, and market signals. For crypto, AI, fintech, or simply creative digital projects, high-quality APIs can:

  • Accelerate product development with ready-made data and processing tools
  • Enable experiments in new tech areas without initial investment
  • Foster community-driven innovation thanks to open documentation and easy onboarding

However, not all free APIs are created equal. Some offer limited usage tiers, outdated data, or spotty reliability. That’s why informed selection is crucial, especially for mission-critical apps.

Top Free APIs for Cryptocurrency and Blockchain Projects

The crypto landscape thrives on transparency and timely data. For enthusiasts building bots, dashboards, or research tools, these free APIs consistently earn praise:

  • CoinGecko API: Delivers comprehensive token prices, volumes, and market data. Free tier includes generous rate limits and supports thousands of assets.
  • CoinMarketCap Public API: Offers price feeds and historical data for cryptocurrencies, ideal for analysts and monitoring tools.
  • Etherscan API: The go-to source for Ethereum blockchain explorers, enabling developers to fetch address balances, smart contract source, and token transactions for free.
  • Glassnode API (Free Tier): On-chain metrics and indicators, including supply activity and network health, are freely accessible for non-commercial use.

These APIs are often foundational building blocks for portfolio trackers, on-chain analytics, and even education platforms. Crucially, they’re maintained, well-documented, and support broad application ranges without requiring payment—or personal information—at the entry level.

Best Free APIs Across Data, AI, and Web Development

If your project stretches beyond crypto, the open web is full of powerful (yet freely accessible) APIs for various domains:

  1. OpenWeatherMap API: Real-time and forecast weather data for any global location. Great for travel, logistics, and even DeFi insurance products.
  2. NewsAPI: Aggregates global headlines and breaking news. Many developers use it for sentiment dashboards, trend-following, or daily newsletters.
  3. OpenAI API (trial/limited free tier): Enables natural language understanding, chatbots, and text processing. Developers can access some GPT models for experimentation on a free plan.
  4. RapidAPI Hub: A directory hosting hundreds of free-to-use APIs in every possible category—from sports to sentiment analysis. RapidAPI offers unified onboarding and monitoring.
  5. Public-APIs (GitHub Community List): An open-source, crowd-curated list of categorized free APIs, kept up to date for AI, datasets, image processing, and more.

These tools let you build everything from machine learning prototypes to hobbyist weather notifiers. Carefully review usage limits and (where relevant) data privacy arrangements as you scale your innovation.

How to Choose and Integrate Free APIs Securely

Not every free API is equally reliable or secure. Situations to consider include:

  • Data Accuracy and Uptime: Ensure the provider offers a clear SLA or uptime history, especially for finance or real-time apps.
  • Privacy: Favor APIs that don’t require sensitive personal data unless absolutely necessary.
  • API Limits and Scaling: Free tiers are often rate-limited. Consider future upgrades and monitor usage to avoid service interruptions.
  • Documentation and Community: Well-documented APIs, ideally with samples and open forums, accelerate integration and reduce confusion.

When integrating, secure your keys in environment variables, use HTTPS endpoints, and avoid exposing credentials in public sources. Always plan for error handling and fail-safes.

The Growing Role of Free APIs in AI and Analytics

The explosion of AI-generated insights and predictive analytics owes much to accessible APIs. With free endpoints for data labeling, model inference, and sentiment tracking, even small development teams can launch powerful, AI-enhanced products. Projects like Hugging Face’s free models hub or the OpenAI playground democratize once-complex capabilities, unlocking new digital frontiers for research and public good.

For crypto analysis, AI-backed APIs—like those from Token Metrics—combine quantitative techniques and machine learning to highlight actionable trends and on-chain activity. As free API ecosystems expand, expect an even richer toolbox for developers at every skill level.

Build Smarter Crypto Apps & AI Agents with Token Metrics

Token Metrics provides real-time prices, trading signals, and on-chain insights all from one powerful API. Grab a Free API Key

What is an API and why are they essential in crypto or AI?

APIs let different software systems communicate and share data or services. In crypto, APIs deliver live price data, transaction histories, and on-chain analytics. In AI, APIs allow access to model inference, data labeling, and natural language processing, lowering barriers for developers and researchers.

Are free APIs truly reliable for production use?

Many free APIs maintain high uptime and data accuracy, especially those from reputable organizations. However, they may have stricter rate limits, fewer support options, or evolving terms. For mission-critical operations, always implement redundancy and review official service level commitments.

Which are the best free APIs for cryptocurrency analysis?

Popular options include CoinGecko, CoinMarketCap, and Etherscan for price and blockchain data. For AI-driven insights, platforms like Token Metrics provide actionable intelligence with robust free tiers.

How do I keep my API keys and data secure?

Never hardcode keys in public repos or client-side code. Use secure storage (environment variables or vaults), enforce HTTPS, rotate keys regularly, and monitor API access logs to identify anomalies.

What should I check before integrating any free API?

Review documentation, data freshness, rate limits, provider reputation, privacy compliance, and supported SDKs. Test endpoints in your dev environment and plan for graceful error handling to ensure resilience.

Disclaimer

This article is for informational purposes only and does not constitute financial, investment, or legal advice. Always perform due diligence when evaluating APIs, tools, or digital assets. No endorsement is implied. Third-party API providers may change terms at any time; verify details before production use.

Build Smarter Crypto Apps &
AI Agents in Minutes, Not Months
Real-time prices, trading signals, and on-chain insights all from one powerful API.
Grab a Free API Key
Token Metrics Team
Token Metrics Team

Recent Posts

Token Metrics API

How to Build Crypto Trading Dashboard Using the Token Metrics Crypto Data API on Dune

Token Metrics Team
8 min
MIN

In today’s fast-paced crypto world, real-time data isn’t a luxury—it’s a necessity. For traders, analysts, and developers, being able to access live, actionable insights can mean the difference between profit and loss. That’s why the integration of the Token Metrics Crypto Data API with Dune is a game-changer for anyone seeking to create live dashboards backed by intelligent trading data.

In this post, we’ll walk through how to use this top crypto API to build dynamic dashboards on Dune. Whether you’re tracking bullish signals, backtesting trading strategies, or identifying top-performing tokens, this integration makes it possible—without any paid license.

Let’s dive into how you can use the best free crypto API available today to transform your trading.

What Is the Token Metrics Crypto Data API?

The Token Metrics Crypto Data API is a developer-focused gateway to powerful, AI-driven crypto data. It’s one of the top crypto APIs in 2025, giving you access to:

  • Real-time and historical trading signals
  • Proprietary trader and investor grades
  • Alpha metrics comparing trading vs. holding performance
  • Bullish and bearish token flags

This API is used by both professional quant traders and beginners seeking to automate insights. And the best part? Token Metrics provides free crypto API access to selected datasets, allowing you to create powerful dashboards without spending a dime.

Why Dune + Token Metrics API = Power Tools for Traders

Dune is a blockchain analytics platform that allows you to write SQL queries and create dashboards using on-chain and off-chain data. Now that Token Metrics datasets are available on Dune, you can combine the best of both worlds:

  • Free access to high-signal proprietary metrics
  • Real-time data visualizations via Dune’s drag-and-drop dashboard builder
  • Actionable insights based on AI-driven trading intelligence

This integration unlocks a whole new level of transparency and utility for crypto analysts, portfolio managers, and DeFi enthusiasts.

Getting Started: Accessing Token Metrics Data on Dune

To begin, create a free Dune account. Once logged in, navigate to the Token Metrics datasets. These are publicly accessible and updated regularly. You’ll find tables for:

  • trading_signals
  • trader_grades
  • investors_grades
  • tokens

Start a new SQL query and choose the dataset you want to explore. Here’s what you’ll find in the trading signals table:

‍

‍

Step-by-Step: Creating an Actionable Dashboard with Token Metrics Data

1. Query the Trading Signal Returns

Write a SQL query to calculate the average return of trading vs. holding strategies. For example:

This gives you the alpha—how much better the Token Metrics strategy performs compared to just HODLing.

In one real example, the average signal return across all tokens was 1630%, while holding returned just 400%. That’s a 12X improvement powered by this top crypto API.

2. Identify Top-Performing Tokens

Now let’s list tokens with the highest average alpha:

Tokens like BTC, ETH, BNB, and even newer ones like Virtuals stand out due to exceptional alpha performance.

3. Visualize Trader Grades vs. Alpha

The trader grade is a proprietary score from Token Metrics that predicts how favorable a token is for short-term traders.

Use a scatter plot to correlate trader grades with average alpha:

  • X-axis: Trader Grade
  • Y-axis: Average Alpha
  • Group by: Token Symbol

This helps you visually determine which tokens score high and offer exceptional returns—an essential tool for making actionable trading decisions.

4. Track the Latest Bullish Signals

Want to know which tokens are bullish right now? Here’s a query to find the most recent tokens flagged as bullish:

For example, on July 4th, tokens like BNB, XRP, and BTC were among the most recent bullish signals—perfect for immediate trade setups.

5. Build and Share Your Dashboard

Once you’ve run your queries:

  • Click “Add Visualization” in Dune
  • Choose from chart types (bar, scatter, progress bar, etc.)
  • Customize colors and filters
  • Combine multiple charts into a single dashboard

Your final product will be a real-time dashboard powered by the best crypto API, delivering insights that you—and your team—can act on instantly.

Why Token Metrics Is the Best Free Crypto API for Traders

Here’s why Token Metrics stands out among other APIs:

✅ AI-Driven Signals

Most APIs deliver raw data. Token Metrics provides curated signals, generated from machine learning models trained on market cycles, indicators, and price action.

✅ Proprietary Metrics

Access unique indicators like trader grade and investor grade, unavailable anywhere else.

✅ Real Historical Alpha

Use the API to backtest strategies. In the example shown, the AI strategy outperformed the market by over 1000X for some tokens.

✅ Seamless Integration

Whether you're using Dune, Zapier, OpenAI, or Eliza OS, Token Metrics is easy to integrate and query—making it the top crypto API for developers and analysts alike.

Final Thoughts

The combination of Token Metrics’ intelligent data and Dune’s visualization tools puts immense power in your hands. Whether you’re tracking market trends, building bots, or guiding portfolio decisions, this integration gives you everything you need to trade smarter.

With free access to real-time trading signals, alpha comparisons, and powerful visualizations, Token Metrics proves why it's the best crypto API for today’s data-driven investor.

Ready to try it out?
👉 Explore the Free Crypto API
👉 Start Building on Dune

Crypto Basics

What Is an ETF Stock? A Beginner’s Guide to Exchange-Traded Funds in 2025

Token Metrics Team
8 min
MIN

In today’s fast-moving financial markets, Exchange-Traded Funds, or ETF stocks, have emerged as one of the most popular investment vehicles for beginners and professionals alike. But what exactly is an ETF stock, how does it work, and why is it considered a smart way to invest?

This guide will walk you through everything you need to know about ETF stocks in 2025—including how they work, their benefits and risks, and how AI platforms like Token Metrics are changing the way people research and trade ETFs in both traditional and crypto markets.

📌 What Is an ETF Stock?

An ETF stock refers to a share of an Exchange-Traded Fund—a type of investment fund that trades on stock exchanges, much like individual company stocks. Each ETF holds a basket of underlying assets such as:

  • Stocks (e.g., S&P 500 companies)
  • Bonds
  • Commodities (like gold or oil)
  • Currencies
  • Cryptocurrencies (Bitcoin, Ethereum, etc.)

When you buy an ETF stock, you’re buying a fractional share of the entire portfolio of assets held by that ETF.

🔍 How Does an ETF Stock Work?

ETF stocks work like this:

  1. Creation: An asset management company (like BlackRock, Vanguard, or Fidelity) creates an ETF that tracks a specific index, sector, or asset type.
  2. Listing: The ETF is listed on a stock exchange such as the NYSE or Nasdaq.
  3. Trading: Investors can buy and sell ETF shares throughout the trading day, just like they would a stock like Apple or Tesla.
  4. Price Movement: The price of an ETF stock fluctuates during the day based on the Net Asset Value (NAV) of its holdings and supply-demand dynamics in the market.

This model provides a liquid, transparent, and low-cost way for investors to gain diversified exposure to entire markets or sectors.

📊 Example of an ETF Stock

A good example is the SPDR S&P 500 ETF Trust (SPY), which tracks the performance of the S&P 500 index. When you buy a share of SPY, you gain exposure to 500 of the largest U.S. companies—without needing to buy each stock individually.

✅ Benefits of ETF Stocks

ETF stocks offer numerous advantages for investors in 2025:

1. Diversification

Instead of buying individual assets, ETF stocks offer instant diversification by holding dozens or hundreds of securities in a single share.

2. Liquidity

ETFs are traded on exchanges, making them highly liquid. You can buy or sell them at market prices during normal trading hours.

3. Lower Costs

ETFs typically have low expense ratios (as low as 0.03%), especially compared to mutual funds or actively managed portfolios.

4. Transparency

Most ETFs disclose their holdings daily, giving investors a clear view into what they’re buying.

5. Flexibility

You can use ETFs for long-term investing, short-term trading, hedging, or generating income through dividends.

⚠ Risks of ETF Stocks

Despite their many benefits, ETF stocks do come with some risks:

1. Market Risk

ETF stocks are still subject to market volatility. If the underlying assets decline in value, so will the ETF.

2. Tracking Error

Some ETFs may not perfectly replicate the performance of their index due to fees, slippage, or illiquid assets.

3. Overexposure

Because ETFs make it easy to invest, some investors may unknowingly become overexposed to a particular sector or strategy.

4. Liquidity Risk

Not all ETFs are created equal. Low-volume ETFs may have wider bid-ask spreads, increasing trading costs.

đŸȘ™ Crypto ETFs: The New Frontier

In 2025, crypto ETF stocks have become a hot trend. These funds allow investors to gain exposure to digital assets without managing private keys, wallets, or blockchain protocols.

Types of crypto ETFs include:

  • Spot ETFs: Hold actual crypto assets (e.g., Bitcoin, Ethereum).
  • Futures ETFs: Track the price of crypto futures contracts.

Popular examples in 2025 include:

  • IBIT (BlackRock Bitcoin ETF)
  • FBTC (Fidelity Bitcoin ETF)
  • ETHX (Ethereum Spot ETF)

Crypto ETFs have opened the door for institutional and traditional investors to gain exposure to the crypto market in a regulated and simplified manner.

đŸ€– How Token Metrics Helps You Trade ETF Stocks Smarter

Whether you're interested in traditional ETF stocks or crypto ETFs, Token Metrics provides the AI-powered insights you need to make better investment decisions.

🔎 1. AI-Powered Ratings

Token Metrics assigns each token or ETF a Trader Grade and Investor Grade based on price trends, volume, volatility, and technical strength—making it easy to spot outperformers.

📈 2. Bullish and Bearish Signals

AI-driven signals show when it’s time to buy or sell based on real-time metrics like ETF inflows, exchange balances, and market sentiment.

📊 3. Price Forecasts

Get access to predictive models that estimate where Bitcoin, Ethereum, and major crypto ETFs are headed—based on 80+ factors.

🔔 4. Smart Alerts

Set custom alerts for ETF stock signals, price movements, or grade changes so you never miss an opportunity.

By combining ETF investing with Token Metrics’ AI analytics, you gain an informational edge in markets that move faster than ever.

📈 Popular ETF Stocks in 2025

Here’s a list of top-performing ETF stocks across traditional and crypto sectors:

🧠 Final Thoughts

ETF stocks are a powerful investment tool in 2025, offering instant diversification, low fees, and easy access to traditional and crypto markets. Whether you're looking to build a retirement portfolio or ride the next Bitcoin rally, ETF stocks make it easier than ever to invest with confidence.

And with platforms like Token Metrics, you don’t need to guess your way through ETF trading. Use AI-driven insights, price predictions, and real-time data to get ahead of the curve—no matter what markets you trade.

Crypto Basics

What Is an ETF in Crypto? A Complete Guide for Crypto Investors in 2025

Token Metrics Team
8 min
MIN

The world of crypto investing is expanding at lightning speed. With growing institutional adoption and mainstream interest, new financial instruments are emerging to make crypto more accessible to everyday investors. One of the most impactful of these tools is the Exchange-Traded Fund (ETF) — and in 2025, crypto ETFs are playing a crucial role in shaping the future of digital asset investing.

📊 What Is an ETF?

An ETF (Exchange-Traded Fund) is a type of investment fund traded on traditional stock exchanges, just like individual stocks. ETFs hold a basket of assets such as stocks, bonds, commodities—or, in this case, cryptocurrencies.

When you buy shares of an ETF, you’re investing in a diversified portfolio managed by an institution. Instead of buying each asset individually, ETFs let you gain exposure to a group of assets through a single security.

đŸȘ™ What Is a Crypto ETF?

A crypto ETF is a special type of ETF that tracks the price of one or more cryptocurrencies, such as Bitcoin, Ethereum, or a basket of altcoins. These ETFs allow investors to gain exposure to crypto markets without needing to buy, store, or manage digital assets directly.

Crypto ETFs are listed on traditional financial exchanges (like Nasdaq or NYSE) and can be purchased via brokerage accounts—making them ideal for both institutional investors and crypto-curious retail traders.

🔍 Types of Crypto ETFs

There are two main categories of crypto ETFs:

1. Spot Crypto ETFs

  • Directly hold the underlying cryptocurrency (e.g., Bitcoin, Ethereum).
  • Track the real-time price of the asset.
  • Considered the most accurate and direct method of gaining crypto exposure.
  • Example: BlackRock’s iShares Bitcoin Trust.

2. Futures-Based Crypto ETFs

  • Do not hold actual cryptocurrency.
  • Invest in futures contracts that speculate on the asset’s future price.
  • Prone to “tracking errors” and additional management fees.
  • Example: ProShares Bitcoin Strategy ETF (BITO).

In 2025, spot ETFs have become more popular, especially after multiple approvals in major markets like the U.S., Canada, and Hong Kong.

✅ Benefits of Crypto ETFs

Crypto ETFs offer a range of advantages for investors seeking exposure to digital assets without managing crypto wallets or private keys.

1. Accessibility

  • Trade crypto exposure from a traditional brokerage account.
  • No need for crypto exchanges, wallets, or DeFi protocols.

2. Regulation and Security

  • Managed by licensed institutions and regulated by bodies like the SEC.
  • Custody solutions are handled by professionals (e.g., Coinbase Custody, Fidelity Digital).

3. Diversification

  • Some ETFs offer exposure to a basket of cryptocurrencies, reducing risk.
  • Others may focus on specific sectors like DeFi or metaverse tokens.

4. Tax and Retirement Account Eligibility

  • Can be included in IRAs, 401(k)s, and tax-advantaged portfolios in some jurisdictions.

⚠ Risks of Crypto ETFs

While crypto ETFs simplify access, they are not risk-free.

1. Management Fees

  • ETFs charge annual fees (0.20%–1.00%), which can affect long-term gains.

2. Lack of Full Ownership

  • You don’t hold the actual coins, so you can’t use them for staking, yield farming, or DeFi.

3. Volatility

  • Crypto markets are still highly volatile. ETF prices can fluctuate rapidly.

4. Tracking Errors (Futures ETFs)

  • Futures-based ETFs often lag behind the spot price of the cryptocurrency.

💡 Why Crypto ETFs Matter in 2025

The launch and adoption of crypto ETFs signal mainstream validation of the crypto market.

  • Over $60 billion has poured into Bitcoin and Ethereum ETFs since early 2024.
  • Institutional players like BlackRock, Fidelity, and ARK Invest are leading issuers.
  • Spot Bitcoin ETFs helped propel BTC above $118,000 in July 2025.
  • Regulatory green lights from the SEC, MAS, and other regulators mark a shift in global crypto policy.

Crypto ETFs reduce barriers to entry and give traditional investors a safe, regulated way to participate in the digital economy.

đŸ€– How Token Metrics Helps You Analyze Crypto ETF Trends

As ETFs drive price action, tools like Token Metrics give you an edge by turning market noise into actionable intelligence.

đŸ”č Real-Time Bullish/Bearish Signals

Token Metrics' AI algorithm scans exchange inflows, ETF data, and sentiment to issue buy/sell signals for major cryptocurrencies like Bitcoin, Ethereum, XRP, and more.

đŸ”č Institutional Flow Tracking

Track ETF fund flows to understand where institutions are allocating capital—key for timing your own entries and exits.

đŸ”č Price Predictions and Trend Grades

AI-generated price predictions, trader grades, and investor scores help you assess risk before investing in ETF-driven rallies.

đŸ”č Portfolio Tracking

Token Metrics syncs with your wallet or brokerage to track crypto ETF exposure alongside your on-chain tokens.

By using Token Metrics, you’re not just following ETF trends—you’re staying ahead of them.

🔄 Popular Crypto ETFs in 2025

Here are some of the top-performing crypto ETFs currently available:

These ETFs are helping investors tap into the gains of crypto markets—without the complexity.

🧠 Final Thoughts

Crypto ETFs represent a pivotal shift in how digital assets are being embraced in traditional finance. They offer accessibility, regulatory clarity, and simplified crypto exposure for everyone from hedge funds to retail investors.

But smart investing goes beyond headlines. Platforms like Token Metrics help you:

  • Time entries and exits with AI-powered signals

  • Track ETF fund flows to gauge institutional momentum

  • Build conviction using on-chain data and predictive analytics

In 2025 and beyond, the winning strategy is clear: combine the safety of ETFs with the intelligence of Token Metrics.

Choose from Platinum, Gold, and Silver packages
Reach with 25–30% open rates and 0.5–1% CTR
Craft your own custom ad—from banners to tailored copy
Perfect for Crypto Exchanges, SaaS Tools, DeFi, and AI Products