🧰 10 Free APIs Every Developer Should Know in 2025 (With Sample Code)

Introduction

Looking to build cool apps but not sure where to get data? Whether you're a beginner or a hobbyist, free APIs are your gateway to building real-world projects without setting up a backend or database.

In this post, you'll discover 10 free, no-auth APIs you can start using right now—along with simple JavaScript fetch examples for each. This resource is perfect for developers who love learning by building.

🛠️ How to Use These APIs

Before we dive in, here's a quick refresher on how to use fetch in JavaScript:

fetch('https://api.example.com/data')
  .then(res => res.json())
  .then(data => console.log(data))
  .catch(err => console.error(err));

Now let’s explore some fantastic APIs 👇

1️⃣ JSONPlaceholder – Fake Data for Testing

Use Case: Practice CRUD operations, build mock apps

fetch('https://jsonplaceholder.typicode.com/posts/1')
  .then(res => res.json())
  .then(data => console.log(data));

💡 Tip: Great for prototyping UI components and testing HTTP methods.

2️⃣ Cat Facts – Random Cat Trivia

Use Case: Fun projects, fact-of-the-day widgets

fetch('https://catfact.ninja/fact')
  .then(res => res.json())
  .then(data => console.log(data.fact));

💡 Tip: Combine it with a cat image API for a full “cat card” experience.

3️⃣ Public Holiday API

Use Case: Add national holidays to calendars or apps

fetch('https://date.nager.at/api/v3/PublicHolidays/2025/US')
  .then(res => res.json())
  .then(data => console.log(data));

💡 Tip: Replace US with your country code to localize results.

4️⃣ CoinDesk – Bitcoin Price Tracker

Use Case: Crypto price monitoring or finance dashboards

fetch('https://api.coindesk.com/v1/bpi/currentprice.json')
  .then(res => res.json())
  .then(data => console.log(data.bpi.USD.rate));

💡 Tip: Display it with a timestamp and auto-refresh for real-time feel.

5️⃣ Bored API – Suggest Activities

Use Case: Random idea generator or boredom buster tools

fetch('https://www.boredapi.com/api/activity')
  .then(res => res.json())
  .then(data => console.log(data.activity));

💡 Tip: Pair it with a timer or productivity app for extra engagement.

6️⃣ Dog CEO API – Dog Image Generator

Use Case: Random dog images in cards, loaders, or fun UIs

fetch('https://dog.ceo/api/breeds/image/random')
  .then(res => res.json())
  .then(data => console.log(data.message));

💡 Tip: Fetch breed-specific images using /breed/{breed}/images.

7️⃣ OpenWeatherMap (Free Tier) – Weather Data

Use Case: Build weather widgets or dashboards

🔐 Requires free API key

const apiKey = 'your_api_key';
fetch(`https://api.openweathermap.org/data/2.5/weather?q=London&appid=${apiKey}`)
  .then(res => res.json())
  .then(data => console.log(data.weather[0].description));

💡 Tip: Cache results locally to avoid rate limits.

8️⃣ JokeAPI – Random Programming Jokes

Use Case: Developer tools, VS Code extensions, humor bots

fetch('https://v2.jokeapi.dev/joke/Programming')
  .then(res => res.json())
  .then(data => console.log(data.joke || `${data.setup} - ${data.delivery}`));

💡 Tip: Use this in Slack bots or daily coding dashboards.

9️⃣ REST Countries – Country Data and Flags

Use Case: Geography quizzes, country selectors, travel apps

fetch('https://restcountries.com/v3.1/name/canada')
  .then(res => res.json())
  .then(data => console.log(data[0].flags.png));

💡 Tip: Use fields=name,flags to keep results lightweight.

🔟 Zen Quotes – Daily Inspiration for Developers

Use Case: Quote of the day widgets or mental health apps

fetch('https://zenquotes.io/api/random')
  .then(res => res.json())
  .then(data => console.log(data[0].q + ' — ' + data[0].a));

💡 Tip: Combine this with CSS animations for a beautiful UX.

🎁 Bonus: Where to Find More Free APIs

Public APIs GitHub List
RapidAPI Hub
API Ninjas
Dev Resources – our curated tools for developers

✅ Best Practices for Using Free APIs

Always check rate limits and terms of use
Use error handling and fallback states
Cache responses when possible
Don’t rely on them for production apps without backups

🌐 SEO Tie-In

Using free APIs helps you quickly build feature-rich prototypes that boost user engagement, page time, and interactive UX—all good for SEO. A weather widget, quote generator, or live dashboard can improve your site’s usefulness and shareability.

🎯 Conclusion

Free APIs are an incredible tool for learning and building. Whether it’s displaying dog images, checking the weather, or getting holiday data, the possibilities are endless.

Try mixing and matching these APIs to create your own mashup projects!

👉 Don’t forget to explore our Projects section to apply these APIs in real-world builds.