15 Best Free APIs Every Developer Should Know in 2026

Look, we've all been there. You're building your next killer app at 2 AM, fueled by coffee and delusion, when you realize: "Wait, I need real data." Do you build a backend from scratch? Scrape websites like a digital criminal? Or spin up a database just to store... weather information?

Hell no. You use an API.

APIs are like having a really smart friend who knows everything about weather, or payments, or cat GIFs (yes, that's a thing). You ask a question, they give you an answer. Simple, beautiful, and best of all—free.

Here are 15 APIs that'll make you look like a coding wizard without selling your kidney to AWS.

What Even Is a Public API?

Think of an API (Application Programming Interface) as a waiter at a restaurant. You (the frontend) tell the waiter what you want. The waiter takes your order to the kitchen (the backend). The kitchen makes your food (processes your request), and the waiter brings it back to you (returns the data).

Except this waiter works 24/7, never spills drinks, and is free.

Public APIs are APIs that companies make available for developers to use. Most have free tiers—perfect for students, hobbyists, and developers who are broke but ambitious.

Types You'll Encounter:

REST APIs: The bread and butter. Uses HTTP (GET, POST, etc.) and returns JSON. If APIs were pizza, REST would be pepperoni—classic and reliable.
GraphQL APIs: The hipster coffee of APIs. You ask for exactly what you want, nothing more. No over-fetching, no bloat.
SOAP APIs: The enterprise dinosaur. Uses XML, overly complex, and makes you question your career choices.
Webhooks: Event-driven magic. Instead of constantly asking "Is it done yet?" (polling), webhooks tap you on the shoulder when something happens.

Alright, enough theory. Let's get to the good stuff.

1. OpenWeather API ☀️🌧️

Link: https://openweathermap.org/api

Want to build a weather app? Of course you do. Everyone's first "real" project is a weather app. It's like the "Hello World" of actual applications.

OpenWeather gives you current weather, 5-day forecasts, and historical data for any location on Earth. Sane people use this to build travel apps and dashboards. I once used it to prove to my roommate that it was, in fact, "sweater weather."

The catch: Free tier limits you to 60 calls per minute. If you're checking the weather more than once per second, you have bigger problems than API limits.

Use it for:

Weather apps (duh)
Travel planners
"Should I go outside today?" decision engines

2. Stripe API 💳

Link: https://stripe.com/docs/api

Stripe is how you take money from people online without becoming a payment security expert (which takes 10 years and costs your sanity).

Want to accept credit cards? Stripe. Want subscriptions? Stripe. Want to feel like a real business? Stripe.

The API is so well-designed it makes you emotional. The documentation actually makes sense. The test mode lets you pretend to process payments with fake credit cards (4242 4242 4242 4242 is your new best friend).

The catch: It's free to integrate, but Stripe takes ~2.9% + 30¢ per transaction when you process real money. That's fair—they're handling all the PCI compliance nightmares you don't want to touch.

Use it for:

E-commerce platforms
SaaS billing
Literally any time money needs to change hands digitally

3. GitHub API 🐙

Link: https://docs.github.com/en/rest

The GitHub API lets you access everything about GitHub repositories, users, and commits. Want to build a GitHub profile analyzer? Portfolio tracker? Automated bot that stars repos at 3 AM? You got it.

You can pull:

User profiles (stalking made easy)
Repository data (stars, forks, commits)
Issues and pull requests (for your project management dashboard)
Followers (for that sweet, sweet social proof)

Pro tip: For public data, you get 60 requests per hour. Authenticated? 5,000. Always authenticate.

Use it for:

Developer portfolio sites
Contribution trackers
Bots that auto-close issues labeled "wontfix"

4. NASA API 🚀🌌

Link: https://api.nasa.gov

NASA gives you free access to space data. Let me repeat: Space. Data.

Astronomy photos, Mars rover images, satellite imagery, near-Earth asteroids—this API is what happens when the smartest people on Earth decide to share their toys.

The Astronomy Picture of the Day (APOD) endpoint alone is worth building an app around. Every day, NASA posts a new mind-blowing image of the cosmos. Your job? Display it with a nice UI and feel like you work at SpaceX.

The catch: Requires an API key, but it's instant and free. They're literally giving you space data. Don't abuse it.

Use it for:

Astronomy apps
Educational platforms
Wallpaper apps for nerds (guilty)
Proving that space is, indeed, the final frontier

5. ZenQuotes API 💭

Link: https://zenquotes.io

Need inspirational quotes? Motivational wisdom? Something to display on your productivity app while users procrastinate?

ZenQuotes has you covered with quotes from Aristotle to Steve Jobs. It's free, doesn't require an API key for basic usage, and returns beautiful JSON.

Use it for:

Daily motivation apps
Landing page hero sections
Making your app seem more philosophical than it is

Example response:

{
  "q": "The only way to do great work is to love what you do.",
  "a": "Steve Jobs"
}

Simple. Clean. Inspiring. Unlike your codebase at 4 AM.

6. Open Library API 📚

Link: https://openlibrary.org/developers/api

Open Library is like Wikipedia for books. It has data on millions of books, authors, and editions. Want to build a reading tracker? Book recommendation engine? Digital library? This is your goldmine.

You can search by ISBN, title, author, or just browse. The best part? It's run by the Internet Archive, so you know it's legit and not going anywhere.

Use it for:

Book apps
Reading challenges
"What should I read next?" engines
Pretending you read more than you actually do

7. Unsplash API 📸

Link: https://unsplash.com/developers

Unsplash is where photographers upload high-quality photos for free. The API lets you search and embed these images in your apps.

Need a random beautiful image? One API call. Need images of "mountain sunrise" or "coffee shop aesthetic"? Got you.

The catch: You need to credit the photographer (which is the bare minimum decent thing to do). Also, 50 requests per hour on the free tier.

Use it for:

Blog post headers
Background images
Making your app look professional when you have zero design skills

8. ExchangeRate-API / Fixer.io 💱

Links:

Currency conversion APIs give you real-time exchange rates. Building an e-commerce site that accepts multiple currencies? International budget tracker? Crypto converter?

These APIs return rates for 150+ currencies, updated daily (or in real-time for paid tiers).

Use it for:

E-commerce platforms
Travel budget calculators
Making your app feel global

9. Twilio API 📱

Link: https://www.twilio.com/docs/usage/api

Twilio lets you send SMS messages and make phone calls from your code. Yes, you can literally make your app text people.

Want to send:

OTP codes for 2FA?
Order confirmations?
Notifications when your server crashes (so you can panic faster)?

Twilio is the answer. They give you free trial credits to test everything.

The catch: Once you go live, you pay per message/call. But it's cheap and way better than building your own SMS infrastructure (please don't).

Use it for:

Two-factor authentication
Notification systems
Reminding users about literally anything

10. Giphy API 🎉

Link: https://developers.giphy.com

Giphy is the GIF library of the internet. Their API gives you access to millions of GIFs, stickers, and animated reactions.

Want to add a GIF search to your chat app? Reaction GIFs to your social platform? A random GIF button because why not?

The catch: You need an API key, but it's free and instant.

Use it for:

Chat applications
Social media platforms
Making literally anything more fun

Fun fact: Searching "programming" returns GIFs of people crying at their computers. Very relatable.

11. News API 📰

Link: https://newsapi.org

News API gives you current headlines and articles from 80,000+ news sources worldwide. Want to build a news aggregator? Custom news feed? Or just display "Tech News" on your portfolio site?

You can filter by:

Category (business, tech, sports, etc.)
Country
Source
Keywords

The catch: Free tier is limited to 100 requests per day and doesn't allow use in production apps (development only). Paid tier removes restrictions.

Use it for:

News apps
Content aggregators
Dashboard widgets

12. Mapbox API 🗺️

Link: https://docs.mapbox.com/api

Mapbox is what you use when Google Maps API pricing makes you cry. It gives you beautiful, customizable maps, turn-by-turn navigation, and geocoding.

Unlike Google, Mapbox has a generous free tier (50,000 requests per month) and doesn't require a credit card for basic usage.

Use it for:

Location-based apps
Delivery tracking
"Find nearby X" features
Custom map styles that don't look like Google Maps

13. JSONPlaceholder 🎭

Link: https://jsonplaceholder.typicode.com

JSONPlaceholder is a fake API with fake data. "Why would I want fake data?" you ask. Because you're testing your frontend and don't have a backend yet!

It has:

100 fake posts
500 fake comments
100 fake photos
10 fake users

You can GET, POST, PUT, DELETE—it pretends to work perfectly. It's like a punching bag for learning API integration.

Use it for:

Learning fetch/axios
Testing frontend code
Building demos
Procrastinating on building a real backend

14. JokeAPI 😂

Link: https://jokeapi.dev

JokeAPI returns random jokes. Programming jokes, dark humor, puns—it has categories.

Sample response:

{
  "category": "Programming",
  "type": "single",
  "joke": "Why do programmers prefer dark mode? Because light attracts bugs.",
  "flags": { "nsfw": false, "religious": false, "political": false }
}

Use it for:

Fun widgets
Chatbots
Making your app 2% funnier

15. IPify API 🌐

Link: https://www.ipify.org

IPify returns your public IP address in one API call. That's it. That's the whole API.

curl 'https://api.ipify.org?format=json'

Response:

{ "ip": "98.207.254.136" }

It's simple, fast, and weirdly satisfying.

Use it for:

Network debugging
Location features (combine with IP geolocation)
Logging user IPs (ethically, of course)

Bonus Tips for Using Free APIs

Always read the docs - I know, shocking advice. But rate limits, authentication, and response formats vary wildly.
Respect rate limits - If you hammer a free API like it owes you money, you'll get blocked. Cache responses when possible.
Handle errors gracefully - APIs fail. Networks fail. Servers crash. Always have a fallback or retry logic.
Never expose API keys in frontend code - Seriously. Use environment variables. Proxy through your backend. Don't be that developer who leaks keys on GitHub.
Give credit - If an API requires attribution (like Unsplash), do it. It's the right thing to do.

The Bottom Line

These 15 APIs can power your next side project, portfolio piece, or even a startup MVP. They provide real-world functionality without the headache of building everything from scratch.

Whether you're adding weather to your app, processing payments, or just displaying random cat GIFs (wait, I forgot to include a cat API—my bad), there's a free API for that.

Pro developer secret: Half of "impressive" apps are just creative combinations of free APIs with a nice UI on top. Don't tell anyone.

Which API Will You Try First?

Personally, I'm partial to the NASA API (space is cool) and JSONPlaceholder (saved my sanity during too many frontend projects).

Drop a comment with:

Which API you're most excited about
Any free APIs I missed (there are hundreds!)
What you're building with them

Now stop reading and go build something. The internet is waiting for your next great app. 🚀

P.S. - If you found this helpful, share it with a friend who's still manually entering fake data in their test apps. They'll thank you.

P.P.S. - Yes, I know there's a Dog API, Cat API, Pokémon API, and 47 other niche APIs I didn't include. This is a starter pack, not an encyclopedia. Go forth and Google.

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15 Best Free APIs Every Developer Should Know in 2026