HTTPX vs AIOHTTP vs Requests: Which to Choose?

Python has three well-known libraries for sending HTTP (Hypertext Transfer Protocol) requests: HTTPX, AIOHTTP, and Requests. All of these have their own unique benefits and drawbacks.

Generally, you’ll want to use Requests for synchronous HTTP requests, HTTPX when you need a mix of both synchronous and asynchronous, and AIOHTTP when you need only asynchronous requests.

Requests Library

Requests is likely among the most popular Python libraries. The built-in “urllib3” and other HTTP request libraries are quite complicated and hard to parse. Requests was made to simplify the process of sending HTTP requests.

You can install the library through pip:

python -m pip install requests

Once that’s installed, you’ll need to import the library. You can send various HTTP requests by adding a method named after the request (e.g., get; post; delete).

import requests
response = requests.get("https://example.com")
print(response.text)

Simplicity is the main selling point for Requests , especially when compared to urllib3. Most of the methods and functions are extremely intuitive, making the library great for beginners.

It’s also often used in Python web development in combination with various browser automation tools such as Selenium.

Requests vs Other Libraries Rundown

Unfortunately, the library also has a few major drawbacks:

1. No async support Requests is intended for synchronous programming. While you can work around the issue, it’s often better to pick HTTPX or AIOHTTP for the job.

2. No HTTP/2 support Requests uses HTTP/1.1, which is a slower version of the protocol. When comparing Requests vs HTTPX or AIOHTTP, it’ll always be the slower library.

3. Built upon “urllib3” Requests inherits all of the benefits and drawbacks of “urllib3” since it’s built upon it. There’s less room for improvement over time, even if the library does have massive community support.

HTTPX Library

HTTPX is a library that’s inspired by Requests, but attempts to fix all of the issues associated with it. As such, HTTPX provides both async compatibility and HTTP/2 support.

These major improvements make HTTPX a popular library. Additionally, since it’s inspired by Requests, most of the methods and functions are identical.

python -m pip install httpx

Once you have the library installed, import it. Most of the methods are identical – every HTTP request is a method associated with the name of it.

import httpx
response = httpx.get("https://example.com")
print(response.text)

Async compatibility follows a fairly standard structure for sending HTTP requests.

import httpx
import asyncio

async def fetch(url):
    async with httpx.AsyncClient() as client:
        response = await client.get(url)
        return response.status_code, response.text

async def main():
    url = "https://www.example.com"
    status_code, content = await fetch(url)
    print(f"Status Code: {status_code}")
    print(f"Content: {content[:100]}...")  # Printing only the first 100 characters

if __name__ == "__main__":
    asyncio.run(main())

While you can use “asyncio” with Requests, it would involve wrapping a synchronous call in an asynchronous wrapper, which might not be as efficient as using a library designed for asynchronous I/O from the ground up.

HTTPX vs Other Libraries Rundown

As with any other library, there’s some drawbacks to HTTPX:

1. Relatively new

When comparing Requests vs HTTPX, the latter is significantly newer. While it’s been getting more stable and more supported, the library still has a ways to go.

2. Higher dependencies HTTPX has more dependencies than Requests, which may be important in environments where minimizing them is crucial.

3. Learning curve HTTPX has a lot of functionality as it combines synchronous and asynchronous compatibility. Both AIOHTTP and Requests focus only on one, making them somewhat easier to learn.

AIOHTTP Library

Finally, the third member of the HTTPX vs Requests vs AIOHTTP group is a library intended for asynchronous programming only . It’s built on the “asyncio” framework, making it a library for sending HTTP requests asynchronously from the ground up.

AIOHTTP, however, is completely different from both HTTPX and Requests. It’s somewhat harder to use as sending a single HTTP request requires a few lines of code. AIOHTTP developers know that – there’s even a dedicated page to explain why .

To get started, you’ll need to first install the AIOHTTP library:

python -m pip install AIOHTTP

Setting up the entire process is a bit more complicated and requires some explanation.

import aiohttp
import asyncio

async def fetch(url):
    async with aiohttp.ClientSession() as session:
        async with session.get(url) as response:
            print(f"Status: {response.status}")
            content = await response.text()
            print(f"Body: {content[:100]}...")  # Print the first 100 characters of the body

async def main():
    url = "https://www.example.com"
    await fetch(url)

# Run the main function
if __name__ == "__main__":
    asyncio.run(main())

After importing the libraries, we’ll have to define a few functions.

The “fetch” function is the one where we’ll be sending out a GET HTTP request. Unlike regular Python functions, we have to include “async” to make it an asynchronous function.

First, we have to create a session object, which allows us to send numerous HTTP requests with the same parameters. “Async with” closes the session after the block is exited, even if an exception occurs. Part of the reason is performance and protection from leaks, the other part is syntactic sugar.

“Async with” does the same in the next line. We do, however, then use the session object to send a GET HTTP request.

Printing outputs is relatively self-explanatory. The content object, however, has one main difference – “await”, which freezes that instance of the “fetch” function. While that call is frozen, other instances of “fetch” (or other asynchronous functions in general) can be run in parallel.

As such, the power of Requests vs AIOHTTP (and, in some measure, HTTPX) is clear. With AIOHTTP you can run several HTTP requests at the same time instead of sending one after another.

AIOHTTP vs Other Libraries Rundown

As with other libraries, there are a few major drawbacks:

1. No synchronous support

It’s not a library built for synchronous requests, so when comparing Requests vs AIOHTTP, you use the former for synchronous and the latter for asynchronous. There’s no reason to do otherwise.

2. Learning curve and complexity

Out of all three, it’s the most complicated library to learn.

3. Debugging difficulties

When comparing Requests vs AIOHTTP for large code bases, the former will always be easier to debug than the latter.

Comparing HTTPX vs AIOHTTP vs Requests

When picking between all three major HTTP requests libraries, you should first decide whether you need synchronous or asynchronous compatibility. Either one will remove one of the libraries, leaving you with either Requests vs HTTPX or HTTPX vs AIOHTTP.

Additionally, consider the project scope. If you need to send a few HTTP requests for web scraping or any other means, the simpler libraries will serve you much better, leaving HTTPX vs Requests to choose from. If you need to send asynchronous HTTP requests on a major code base, there’s only one option – AIOHTTP.

Finally, optimization questions also play a part in your choice between HTTPX vs Requests vs AIOHTTP. If networking speeds and performance play a part in your project, HTTPX vs AIOHTTP are the two to choose from.