Best Public APIs 2026

Frequently Asked Questions

Where can I find free public APIs to build with?▾

Public APIs (github.com/public-apis/public-apis) is the most comprehensive open-source list of free APIs. RapidAPI is the largest API marketplace with both free and paid tiers. APIList.fun and any-api.com curate categorized API directories. For data APIs specifically, Data.gov and World Bank Open Data provide free government and international datasets.

What is the difference between REST and GraphQL APIs?▾

REST APIs have fixed endpoints that return predefined data structures - simple, widely supported, and cacheable. GraphQL APIs have a single endpoint where you specify exactly what data fields you need - reducing over-fetching, enabling complex nested queries in one request, and making schema exploration easy. REST is more common; GraphQL is preferred when frontend teams need flexible data fetching.

How do I authenticate with APIs that require API keys?▾

Store API keys in environment variables (never in source code). Pass them in request headers (Authorization: Bearer {key}) or as query parameters (as the API documentation specifies). Use a secrets management service (.env locally, Vault or AWS Secrets Manager in production) to keep keys out of version control. Rotate keys periodically and immediately if exposed.

What is a public API?▾

A public API is an interface a service exposes so external developers can access its data or functionality programmatically, for example a weather API providing forecasts, a maps API providing location services, or a payment API processing transactions. Instead of building such capabilities yourself, you call the API and integrate its data or features into your application. Public APIs are the building blocks of connected software, letting you assemble applications from proven services. They range from free open APIs to paid commercial ones, covering nearly every domain, and they are fundamental to how modern applications are built.

Where can I find public APIs?▾

API directories are the main way: RapidAPI is a large marketplace of thousands of APIs, APIs.guru catalogs many, and the Public APIs list on GitHub is a popular community-maintained collection of free public APIs by category. Major platforms like Google, Stripe, and Twilio have their own developer portals documenting their APIs. To find an API for a specific need, searching these directories by category or capability is the fastest approach. They let you discover, compare, and access APIs across every domain, so whatever data or functionality you need, a directory is the place to start looking.

Are public APIs free to use?▾

It varies. Many public APIs offer free tiers or are entirely free, especially open data and community APIs, while commercial APIs typically charge based on usage, requests, volume, or features, often with a free tier for testing and low use. Even free APIs usually have rate limits. Before building on an API, check its pricing, limits, and terms, since costs can grow with usage and some APIs restrict commercial use or require attribution. Plan for the pricing model of any API central to your application, since depending on a paid API means its costs scale with your usage.