In this post, we'll:

✅ Compare Actix-Web vs. FastAPI in a "Hello, World!" API

✅ Examine their ecosystems (libraries, middleware, async support)

✅ Benchmark performance (spoiler: Actix-Web is blazingly fast!)

1. "Hello, World!" API Comparison

🔹 FastAPI (Python)

Create a new file main.py for this example and paste the following code

🔹 Actix-Web (Rust)

In order to create our first API in rust we will create a new Project using this command

Directory Structure Will look like 

Now we will edit src/main.rs file and add following code alternative to FastAPI

As you can see in above Code there is a Macro 'json' from 'serde_json' library
serde_json::json 

which is used to construct a json value.

We will add this dependency in our project using 

Let's run our Actix Demo API using command

if you go to this URL localhost:8080/ 

you can see the Hello World message

🔶 Key Differences

2. Ecosystem Comparison

🔹 FastAPI Ecosystem

✅ Dependency Injection – Built-in

✅ Data Validation – Pydantic

✅ ORM Support – SQLAlchemy, TortoiseORM

✅ Middleware – Starlette-based

✅ Auth – OAuth2, JWT (via fastapi.security)

🔹 Actix-Web Ecosystem

✅ Dependency Injection – actix-web + awc

✅ Data Validation – validator crate

✅ ORM Support – Diesel, SQLx

✅ Middleware – Built-in (wrap_fn, Logger)

✅ Auth – actix-web-httpauth, jsonwebtoken

🔶 Ecosystem Summary

3. Performance: Actix-Web vs FastAPI

Rust’s zero-cost abstractions and fearless concurrency make Actix-Web significantly faster than FastAPI in benchmarks.

🔹 TechEmpower Benchmark (Round 21)

💡 Actix-Web is ~3.5x faster than FastAPI!

4. When to Choose Actix-Web Over FastAPI?

✅ You need maximum performance (microservices, APIs, real-time systems)

✅ You want Rust’s memory safety (no runtime crashes, no GC pauses)

✅ You need strong concurrency (Actix’s actor model scales effortlessly)

🚫 Avoid Actix-Web if:

Final Verdict: Is Actix-Web the Best FastAPI Alternative?

Yes! If you want Rust’s speed + safety in web development, Actix-Web is the best FastAPI alternative. While FastAPI is great for rapid Python development, Actix-Web dominates in raw performance, safety, and scalability.

🚀 Ready to Try Actix-Web?