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 Some offer limited usage tiers, outdated data, or spotty reliability.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.

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Token Metrics Team
Token Metrics Team

Recent Posts

Crypto Basics

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

Token Metrics Team
8 min
MIN

In today’s fast-paced financial markets, ETF trading has become one of the most popular and accessible investment strategies. Whether you're a traditional investor or a crypto enthusiast, understanding how ETF trading works can help you make smarter, more diversified investment decisions.

📈 What Is an ETF?

An ETF (Exchange-Traded Fund) is an investment fund that trades on stock exchanges, similar to individual stocks. Each ETF holds a collection of assets, such as:

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

When you buy a share of an ETF, you're buying a fractional interest in the entire basket of assets. This makes ETFs a powerful tool for diversification, even for beginners.

đŸ’č What Is ETF Trading?

ETF trading refers to the buying and selling of ETF shares on an exchange—just like you would with Apple or Tesla stock. The value of an ETF changes throughout the trading day, based on the underlying value of its assets.

ETF trading is commonly used for:

  • Portfolio diversification
  • Hedging strategies
  • Thematic investing (e.g., AI, clean energy, DeFi)
  • Speculating on short-term price movements

You can trade ETFs via your online brokerage, investment app, or even through certain retirement accounts (like IRAs).

🔄 How Does ETF Trading Work?

Here’s a simplified version of how ETF trading works:

  1. ETF Provider Creates the Fund
    A company like BlackRock or Fidelity creates an ETF that holds a specific basket of assets.

  2. ETF Listed on an Exchange
    The ETF is listed on public stock exchanges such as the NYSE or Nasdaq.

  3. Investors Buy and Sell Shares
    Investors trade ETF shares just like stocks—prices fluctuate throughout the day.

  4. Market Makers Maintain Liquidity
    Authorized participants ensure ETF prices closely match the value of the underlying assets (called the Net Asset Value or NAV).

đŸȘ™ What About Crypto ETFs?

In 2025, crypto ETFs have emerged as one of the fastest-growing segments of the ETF market.

Crypto ETFs allow investors to gain exposure to cryptocurrencies without owning the actual coins. These ETFs are regulated, secure, and accessible through traditional finance platforms.

There are two types:

  • Spot Crypto ETFs (hold actual crypto assets like Bitcoin or Ethereum)
  • Futures Crypto ETFs (track the price of crypto futures contracts)

Example: BlackRock’s iShares Bitcoin Trust (IBIT) is a spot Bitcoin ETF with billions in assets under management (AUM) in 2025.

✅ Benefits of ETF Trading

ETF trading offers unique advantages for both retail and institutional investors:

1. Diversification

Instead of buying dozens of individual stocks, ETFs offer broad exposure to sectors, themes, or markets in a single trade.

2. Liquidity

ETFs trade like stocks—buy or sell at any time during market hours. This makes them more flexible than traditional mutual funds.

3. Cost Efficiency

Many ETFs have low expense ratios, often under 0.25%. You avoid the high fees associated with actively managed funds.

4. Accessibility

Trade ETFs using any brokerage account. You don’t need to be an accredited investor or a crypto expert.

5. Tax Advantages

ETFs are generally more tax-efficient than mutual funds due to the in-kind creation/redemption process.

⚠ Risks of ETF Trading

ETF trading, like all investing, carries risks:

1. Market Risk

ETF prices can go up or down depending on market conditions.

2. Liquidity Risk

Not all ETFs are highly traded. Low volume can lead to wide bid/ask spreads and slippage.

3. Tracking Error

Some ETFs fail to perfectly mirror their benchmark, especially futures-based crypto ETFs.

4. Sector Risk

Thematic ETFs (e.g., blockchain, AI) can be highly concentrated and volatile.

🧠 How Token Metrics Enhances ETF Trading with AI

Whether you're trading traditional ETFs or crypto-focused ones, Token Metrics provides AI-powered tools to help you trade with confidence.

🔍 1. Real-Time Signals

Token Metrics offers AI-generated bullish/bearish signals for Bitcoin, Ethereum, and other assets—helping you identify the best time to enter or exit.

📊 2. Price Predictions

The platform generates short- and long-term price forecasts, using 80+ data points. This can help you anticipate ETF price movements, especially for crypto ETFs.

📈 3. On-Chain Data + ETF Flows

Token Metrics tracks exchange reserves, ETF inflows, and blockchain metrics—giving traders a unique edge not available on traditional brokerage platforms.

📣 4. Alerts and Custom Grades

Set up alerts based on trader grades, investor grades, and signal changes to react to market moves instantly.

đŸ”„ Example: Trading Bitcoin ETFs Using Token Metrics

Let’s say you want to trade the BlackRock Bitcoin ETF in July 2025. Here’s how Token Metrics can help:

  • AI signaled bullish BTC trend on June 28
  • Price surged from $106,000 to $118,000
  • ETF inflows increase as institutional demand grows
  • You receive a buy alert from Token Metrics
  • You enter the ETF early and ride the momentum

This combination of real-time AI alerts + institutional trend analysis gives you a significant advantage over traditional investors.

🧭 Final Thoughts

ETF trading has changed the game for investors. Whether you're looking to diversify your portfolio, gain exposure to crypto, or automate your trading strategy—ETFs provide a flexible, affordable, and efficient solution.

And in 2025, combining ETF trading with Token Metrics' AI-powered platform is one of the smartest ways to stay ahead.

With features like real-time signals, crypto ETF tracking, price predictions, and custom alerts, Token Metrics transforms how you approach modern ETF markets.

Crypto Basics

What Is a Bitcoin ETF? A Beginner’s Guide to Understanding Bitcoin Exchange-Traded Funds in 2025

Token Metrics Team
8 min
MIN

The cryptocurrency world continues to evolve rapidly, and one of the most significant milestones in recent years has been the approval and rise of Bitcoin ETFs. If you’ve ever wondered, “What is a Bitcoin ETF and why is it important?” — this guide breaks it down in simple terms.

In this highly informative blog, we’ll explore:

  • What a Bitcoin ETF is
  • Types of Bitcoin ETFs
  • Benefits and risks
  • Why Bitcoin ETFs matter for crypto adoption
  • How to analyze Bitcoin ETFs using Token Metrics tools

📈 What Is a Bitcoin ETF?

A Bitcoin ETF (Exchange-Traded Fund) is a financial product that allows investors to gain exposure to the price movements of Bitcoin without having to own or manage actual Bitcoin.

Just like buying a stock, investors can purchase shares of a Bitcoin ETF through traditional brokerage accounts. These shares represent ownership in a fund that tracks the price of Bitcoin.

In essence, a Bitcoin ETF bridges the gap between traditional finance and crypto investing.

🔄 How Does a Bitcoin ETF Work?

Bitcoin ETFs are created and managed by large financial institutions or asset managers. These funds:

  1. Buy Bitcoin directly (in spot ETFs), or
  2. Invest in Bitcoin futures contracts (in futures ETFs)
  3. Issue ETF shares that track the price performance of Bitcoin

These shares are then listed on stock exchanges like the NYSE, Nasdaq, or CBOE, where they can be bought or sold just like regular stocks.

🔍 Types of Bitcoin ETFs

There are two main types of Bitcoin ETFs:

1. Spot Bitcoin ETFs

  • Hold actual Bitcoin in custody
  • Track the real-time market price of Bitcoin
  • Provide direct exposure to Bitcoin’s price
  • Approved in the U.S. starting in early 2024 (e.g., BlackRock’s iShares Bitcoin Trust)

2. Futures-Based Bitcoin ETFs

  • Track Bitcoin futures contracts (derivatives)
  • Do not hold actual Bitcoin
  • Subject to contango and tracking errors
  • Were the first type approved (e.g., ProShares BITO)

In 2025, spot ETFs are considered superior due to their more accurate and direct exposure.

✅ Benefits of Bitcoin ETFs

Bitcoin ETFs offer several key advantages:

1. Accessibility

Investors can buy Bitcoin exposure through traditional brokerage platforms like Fidelity, Schwab, or Robinhood—no need for crypto wallets or private keys.

2. Regulation and Security

ETFs are regulated by institutions like the SEC and are managed by trusted financial firms, offering greater transparency and investor protection.

3. Tax Efficiency

Buying and selling ETFs may provide more favorable tax treatment compared to transacting in physical Bitcoin directly.

4. Institutional Adoption

Bitcoin ETFs enable pension funds, hedge funds, and banks to legally and easily gain exposure to BTC. Inflows from these entities have driven billions into Bitcoin in 2024 and 2025.

⚠ Risks of Bitcoin ETFs

Despite their benefits, Bitcoin ETFs come with a few risks:

1. Price Tracking Errors

Futures ETFs may deviate from Bitcoin’s spot price due to volatility and contract rollover costs.

2. Management Fees

ETF providers charge an annual fee (0.20%–1.00%), which can reduce long-term returns.

3. Lack of Custody Control

You don’t actually own Bitcoin when you hold an ETF—so you can’t transfer it or use it for DeFi or crypto payments.

4. Market Volatility

Bitcoin remains a highly volatile asset. ETF shares may still experience massive price swings.

đŸ›ïž Why Bitcoin ETFs Matter in 2025

The approval and adoption of Bitcoin ETFs mark a turning point in mainstream crypto acceptance. Here’s why:

  • Over $60 billion has flowed into U.S.-listed Bitcoin ETFs since January 2024
  • Institutions like BlackRock, Fidelity, and ARK Invest now actively manage Bitcoin exposure
  • Bitcoin ETF holdings reduce circulating supply, contributing to BTC’s price surge past $118,000 in mid-2025
  • Countries outside the U.S., including Canada and Hong Kong, are expanding their Bitcoin ETF offerings

đŸ€– How Token Metrics Helps You Analyze Bitcoin ETFs

While traditional investors focus on ETF tickers, smart crypto investors turn to platforms like Token Metrics to get deeper insights.

đŸ”č AI-Powered Bitcoin Forecasts

Token Metrics uses machine learning to predict short- and long-term Bitcoin price trends. As of June 28, the AI turned bullish, signaling BTC's breakout past $110,000.

đŸ”č Exchange Reserve Monitoring

The platform tracks Bitcoin’s exchange reserves, showing a drop from 3.25M to 2.55M BTC—a bullish signal due to reduced sell-side pressure.

đŸ”č ETF Flow Analysis

Token Metrics integrates on-chain data and fund inflows to measure:

  • How much BTC ETFs are buying
  • Impact on liquidity and price
  • Sentiment shifts among institutional investors

đŸ”č Alerts and Grades

You can set up custom price alerts for Bitcoin and receive Trader and Investor Grades based on 80+ real-time metrics.

These tools allow you to react faster than ETF investors relying on traditional media or quarterly reports.

📈 Bitcoin ETF Performance So Far

As of July 2025:

  • BlackRock’s iShares Bitcoin Trust (IBIT) holds over $18B in BTC
  • Fidelity’s ETF surpassed $12B in AUM
  • ETF buying pressure is one of the main drivers behind Bitcoin’s 2025 bull run

💡 Pro Tips Before Investing in a Bitcoin ETF

  1. Compare fees across ETFs (lower = better for long-term holdings)
  2. Choose spot ETFs over futures ETFs for more accurate performance
  3. Use Token Metrics to track BTC signals and time your entry
  4. Understand your goals—ETFs are great for passive exposure but not for on-chain crypto utility

🧠 Final Thoughts

A Bitcoin ETF is one of the easiest ways to gain exposure to Bitcoin in 2025. Whether you’re a traditional investor looking to diversify or a crypto-native looking for a regulated option, ETFs offer accessibility, safety, and legitimacy.

But don’t stop at just buying shares—pair your ETF exposure with real-time intelligence from Token Metrics.

With institutional momentum accelerating, regulatory clarity improving, and AI tools like Token Metrics giving you an edge, there’s never been a better time to understand and invest in Bitcoin ETFs.

Crypto Basics

Hot Wallets vs. Cold Wallets: What’s the Difference and Which Crypto Wallet To Use in 2025?

Token Metrics Team
8 min
MIN

As cryptocurrency adoption accelerates globally in 2025, one critical question for both beginners and experienced investors is: Where should you store your crypto assets safely?

The answer lies in understanding the difference between hot wallets and cold wallets — the two main categories of cryptocurrency storage. This highly informative and SEO-optimized blog will help you understand:

  • What hot and cold wallets are
  • Key differences between them
  • Pros and cons of each
  • Which one is right for you
  • How platforms like Token Metrics help you choose and manage your wallet securely

🔐 What Is a Cryptocurrency Wallet?

A crypto wallet stores your private and public keys, enabling you to send, receive, and manage digital assets like Bitcoin, Ethereum, or altcoins. Unlike traditional bank accounts, crypto wallets give you full control over your funds — but with that control comes the responsibility of securing them.

Wallets are typically categorized as:

  • Hot Wallets – connected to the internet
  • Cold Wallets – offline storage solutions

⚡ What Is a Hot Wallet?

A hot wallet is a crypto wallet that is connected to the internet. It’s designed for easy access and quick transactions, making it ideal for active traders and everyday use.

đŸ”č Examples of Hot Wallets:

  • Web wallets: MetaMask, Trust Wallet, Phantom, Rainbow
  • Desktop wallets: Exodus, Electrum
  • Mobile wallets: Coinbase Wallet, Atomic Wallet
  • Exchange wallets: Binance, Coinbase (custodial)

✅ Pros of Hot Wallets:

  • Instant access to crypto
  • User-friendly interfaces
  • Ideal for frequent trading or DeFi
  • Compatible with most crypto platforms

❌ Cons of Hot Wallets:

  • Vulnerable to hacks and phishing
  • Depends on internet connection
  • Risk of malware or keylogging
  • Not ideal for large holdings

Hot wallets are often recommended for storing smaller amounts of crypto for daily use.

🧊 What Is a Cold Wallet?

A cold wallet refers to any crypto wallet that is not connected to the internet. It’s a form of offline storage designed for maximum security.

đŸ”č Examples of Cold Wallets:

  • Hardware wallets: Ledger Nano X, Trezor Model T
  • Paper wallets: Printed QR codes with private keys
  • Air-gapped computers: Devices permanently offline

✅ Pros of Cold Wallets:

  • Immune to online attacks
  • Long-term storage for HODLing
  • Control over private keys
  • Ideal for institutional and high-net-worth users

❌ Cons of Cold Wallets:

  • Less convenient for quick access
  • Physical loss or damage is a risk
  • Requires technical knowledge
  • More expensive (hardware wallets can cost $50–$200)

Cold wallets are ideal for long-term investors storing large amounts of crypto.

🔄 Hot Wallet vs. Cold Wallet: Key Differences

🔧 How to Use Hot and Cold Wallets Together (Hybrid Strategy)

Many crypto investors in 2025 use a dual-wallet strategy:

  • Hot wallet for trading, staking, and DeFi
  • Cold wallet for long-term storage and high-value assets

This balances convenience and security while minimizing exposure to threats.

For example:

  • Use a hot wallet like MetaMask to access the Token Metrics Moonshots tab and buy trending altcoins.
  • Transfer profits to your cold wallet (e.g., Ledger) for safekeeping.

🧠 How Token Metrics Helps You Manage Wallet Security

đŸ”č Wallet Integrations

Token Metrics supports:

  • MetaMask, WalletConnect, and other hot wallets
  • Portfolio tracking synced with your wallet
  • Real-time alerts when assets in your wallet are surging or at risk

đŸ”č Smart Trading with AI

Token Metrics helps reduce the need to frequently move funds by:

  • Identifying only high-quality tokens using AI Trader and Investor Grades
  • Sending price alerts, so you know when to buy/sell
  • Providing in-platform swap tools for direct trades from your hot wallet

đŸ”č Moonshot Monitoring

For early-stage altcoins, timing is everything. Token Metrics lets you:

  • Monitor your Moonshot investments
  • Get notified when to take profits or exit
  • Transfer to cold storage with a single click

🔒 Hot Wallet Security Tips (2025 Edition)

If you’re using a hot wallet:

  • Enable 2FA (Two-Factor Authentication)
  • Use a hardware wallet to sign large transactions
  • Avoid clicking suspicious links or connecting to unknown dApps
  • Disconnect wallets after use

Always back up your seed phrase and store it securely offline.

💬 Which Wallet Should You Use?

‍

đŸ§© Final Thoughts

Whether you’re storing $100 or $100,000 in cryptocurrency, your wallet choice directly impacts your security, accessibility, and peace of mind.

  • Hot wallets offer convenience, but must be used with caution
  • Cold wallets offer security, but come with trade-offs in usability
  • Platforms like Token Metrics bridge the gap by offering real-time insights, wallet integrations, and AI-driven trading tools

In 2025, don’t just store your crypto—store it wisely. Combine hot and cold wallet strategies and leverage tools like Token Metrics to build a secure, intelligent crypto portfolio.

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