Best Free Crypto APIs for Developers

CoinGecko is the most commonly used free crypto price API for developers. Its public API (no key required) returns real-time prices, market caps, volumes, and historical data for thousands of coins. The rate limit is 30 calls per minute. CoinMarketCap's free Basic tier (API key required) offers 10,000 calls per month. For simple projects, CoinGecko is usually the better starting point because it requires no signup.

Yes. Etherscan offers a free API tier that allows up to 5 calls per second and 100,000 calls per day after free registration for an API key. The free tier covers balance lookups, transaction history, ERC-20 transfers, block data, and contract ABI fetching. Pro features like advanced filtering and extended historical exports require a paid plan.

The Binance REST API uses a weight system rather than a simple calls-per-minute limit. Each endpoint has a request weight, and the default rate limit is 1,200 weight units per minute per IP address. Market data endpoints — prices, order books, klines — are free and public with no API key required. Trading endpoints require authentication. The WebSocket API has separate connection and message limits.

Yes. Alchemy and Infura both offer free Ethereum RPC tiers that let you query balances, transactions, and call smart contract view functions — essentially a free Ethereum node endpoint. Alchemy's free tier includes 300 million compute units per month. The Graph Protocol lets you query indexed blockchain data via GraphQL for free on public subgraphs. Raw Ethereum data without indexing is free via any public RPC but requires you to parse the data yourself.

CoinGecko's API includes a news endpoint. CryptoPanic offers a free API tier for crypto news aggregation. CoinDesk has a content API. Most news APIs in crypto have limited free tiers — typically a few hundred calls per day — and paywalled historical archives. For research, many developers scrape public RSS feeds from CoinDesk, The Block, and Decrypt, though this is subject to each site's terms of service.

It depends on the provider's terms of service, not just the tier name — 'free' doesn't automatically mean unrestricted commercial use. CoinGecko's free public API terms restrict redistribution and commercial resale of the data itself, while building a commercial product that merely calls the API for display is generally allowed at the free tier's rate limits. Always read the specific provider's terms of service before shipping a commercial product on a free tier, since rate limits, attribution requirements, and resale restrictions vary by provider and can change.

Free-tier crypto APIs almost never come with an uptime guarantee or a formal SLA — that protection is typically reserved for paid tiers. Providers like CoinGecko, CoinMarketCap, and Etherscan publish status pages showing historical uptime, but their free-tier terms of service explicitly disclaim liability for downtime, and there is no service credit or support commitment if the API goes down while your app is depending on it. In practice, free tiers are usually reliable day-to-day because they run on the same shared infrastructure as paid tiers, but they are best-effort — a production application built on a single free-tier endpoint has no contractual recourse if it goes down, and free-tier traffic is often the first to be throttled during a provider-side incident. For anything customer-facing where downtime has a real cost, budget for a paid tier with an SLA or build in a fallback to a second provider.

If a free crypto API provider shuts down or moves its data behind a paywall, any app hard-coded to that single provider breaks immediately, since nothing in a typical free-tier terms of service commits the provider to keep an endpoint free or even keep it running indefinitely. Free tiers are commercially the most disposable part of a data provider's business, so they are the first thing to change when a company's priorities shift. The practical defense is architectural, not contractual: abstract your data-fetching behind a single interface in your own codebase so swapping providers is a config change rather than a rewrite, and keep a lightweight integration with at least one alternate provider ready to go — for price data, CoinGecko and CoinMarketCap can typically substitute for each other, and for on-chain data, Etherscan and a public RPC endpoint can serve as mutual fallbacks.

It depends on the provider, so check their current pricing page rather than assuming a figure — paid-tier pricing changes over time and varies widely by call volume and endpoint type. To estimate what you'll need, count your app's actual calls per minute or day against the free-tier caps listed above (CoinGecko's 30 calls/minute, CoinMarketCap's 10,000/month, Etherscan's 5 calls/second and 100,000/day) and see how far your real traffic exceeds them. Most providers publish tiered plans that scale with call volume, so the closer your usage sits to the free-tier ceiling, the smaller the first paid step usually is.

It depends on what you're building and how live the data needs to be. A DeFi dashboard typically needs on-chain data (wallet balances, contract state) from Etherscan or Alchemy layered with price data from CoinGecko. A trading bot needs low-latency exchange data — the Binance REST API's market endpoints are free and public. If you're building the tracker itself rather than the data layer, /free/free-crypto-trading-tools and /free/free-crypto-portfolio-tracker cover ready-made free tools that already wrap these APIs for you.

Yes, though most free tax tools use a free-tier exchange or blockchain API under the hood rather than exposing raw tax data themselves — you typically export a CSV or connect a read-only API key rather than calling a dedicated 'tax API'. See /learn/free-crypto-tax-tools for a rundown of the free options and what each one actually covers.

Yes, several payment processors offer free-to-integrate APIs where you only pay a per-transaction fee rather than a subscription — there's no cost just to build the integration. See /learn/crypto-payment-gateway for how these APIs work and how to pick one for accepting crypto payments.