5 Free APIs That Saved My Side Project From Surprise Bills

I launched a side project last month. Nothing fancy — a small web app that pulled weather data, checked air quality, and looked up location info. Classic "weekend project" stuff.

Then I got the bill.

I'd signed up for three paid API services without thinking about it. $47/month for what amounts to a hobby project. I'm not a funded startup. That's real money for a side project.

So I went on a hunt for free alternatives. Here's what I found — and why you probably don't need to pay for APIs either.

The Problem With Paid APIs

Most developers reach for the obvious paid service first. Stripe for payments, Twilio for SMS, OpenWeather for weather. They're great products. But here's the thing:

For a side project, you're paying for reliability and scale you don't need yet.

If you have 50 users (or even 500), you don't need enterprise-grade API uptime. You need something that works, is free, and won't send you a surprise invoice at 2am.

API #1: Weather Data (No API Key Needed)

I was using a paid weather API at $12/month. Then I found Open-Meteo — completely free, no API key required, and the response format is actually cleaner than the paid alternatives.

The catch? It only works for weather. No air quality, no historical data, no fancy ML predictions. But for "what's the weather in Tokyo right now?" — it's perfect.

I pulled the weather widget off my app and replaced it with a direct fetch. Two hours of work, $144/year saved.

API #2: Air Quality (Also Free)

This one surprised me. The EPA provides free air quality data through their AirNow API. No key needed for basic queries. You can get AQI readings for any US city.

If you need global data, there are a few options. I ended up using a bundled service that aggregates multiple sources, but the point is: air quality data is public information. You shouldn't be paying $20/month for it.

API #3: IP Geolocation (Zero Cost)

I was paying $8/month for a geolocation service. Turns out, there are several free alternatives that give you city, country, timezone, and even approximate coordinates from an IP address.

The best part? Most of them have generous rate limits — 1,000+ requests per minute for free. Way more than a side project needs.

API #4: Translation (Built Into Your Stack)

If you're paying for a translation API for a small app, stop. Google Translate has a free tier. DeepL has a free tier. And if you're building with Python, there are libraries that wrap these services with no additional cost.

I replaced a $15/month translation API with a simple function that uses a free alternative. Same quality, zero cost.

API #5: QR Code Generation (Why Was I Paying For This?)

I was paying $5/month for a QR code API. Let me save you the trouble: QR code generation is a solved problem. There are free libraries in every language that generate QR codes locally. No API call needed. No rate limits. No monthly fee.

I spent 20 minutes integrating a Python library and never looked back.

The Pattern I Noticed

Every paid API I was using fell into one of two categories:

1. Data that's publicly available — weather, air quality, geolocation. These are public datasets. Someone already aggregated them for free.

2. Commodity operations — translation, QR codes, text processing. These are solved problems with free implementations.

The only APIs worth paying for are ones that provide unique data (real-time financial data, proprietary analytics) or infrastructure (payment processing, email delivery that needs deliverability guarantees).

How I Organized My Free APIs

Here's what my API stack looks like now:

• Weather: Open-Meteo (free, no key)
• Air Quality: EPA AirNow + a bundled aggregator
• Geolocation: Free IP lookup service
• Translation: Free tier from a major provider
• QR Codes: Local generation, no API needed

Total cost: $0/month. Down from $47.

The Real Lesson

The lesson isn't "never pay for APIs." It's "don't pay for APIs you can get for free."

Before signing up for any paid service, ask yourself:

• Is this data publicly available?
• Is there a free alternative with adequate rate limits?
• Am I paying for scale I don't need yet?
• Can I generate this locally instead of calling an API?

For side projects and MVPs, the answer is usually "yes, there's a free option." Save the paid APIs for when you actually need them — when you have users, revenue, and real infrastructure requirements.

What I'd Do Differently

If I started my side project over today, I'd build my API layer first. Pick the free services, understand their limits, and design around them. Then, if I ever need to upgrade, I know exactly what I'm paying for and why.

I've been using a tool called QuotaLink that aggregates several of these APIs in one place — weather, air quality, translation, geolocation. Worth checking out if you want a single endpoint instead of juggling five different services.

What free APIs have you discovered that others might not know about? I'm always looking for more.