If you are looking to build a new side project, practice your backend integration skills, or contribute to an open-source application, one of the best ways to start is by utilizing free public APIs. Why build a complex dataset from scratch when thousands of endpoints already exist?

Here is a curated list of some of the best free (and freemium) public APIs available for developers right now.

The Master Repositories (Bookmark These)

If you just want massive lists to browse for inspiration, start here:

• The “public-apis” GitHub Repo: This is the legendary collective list. It has hundreds of APIs categorized by topic (Animals, Anime, Anti-Malware, Business, etc.).
• RapidAPI’s Top Free APIs: A massive marketplace where you can find and test APIs directly in the browser. They offer data for COVID-19, movies, finance, weather, and more. All APIs return a response in JSON (and sometimes in XML).
• FreePublicAPIs.com: A frequently updated list that even includes a “Health” score for each API, so you don’t waste time on broken endpoints.

Top Standalone APIs to Try Today

Here are a few specific APIs that are excellent for building portfolio projects:

1. ReqRes (For QA & Frontend Testing)

• What it is: A hosted REST API with real endpoints and persistent data, perfect for testing your frontend applications.
• Why it’s cool: You don’t have to deploy servers or set up auth. You can just fetch(url) and get a response in 30 seconds.

2. OpenWeatherMap (Data)

• What it is: Weather data and forecasts. Provides data by city, coordinates, and zip.
• Why it’s cool: It is useful for building weather dashboards, travel apps, or agricultural apps.

3. The Movie Database Alternative (Entertainment)

• What it is: A RESTful web service to access information, pictures, and more from the movie database.
• Why it’s cool: You can build your own IMDB clone and get data like Title, Year, Metascore Rating, Release date, Runtime, Genre, Directors, Writers, Actors, and Plot.

4. GroqCloud (AI / Machine Learning)

• What it is: A free-to-start, high-speed public API platform that offers access to open-source LLMs with ultra-low latency.
• Why it’s cool: You can call its OpenAI-compatible API endpoints to run fast, real-time inference on open-source LLMs like LLaMA and Mixtral.