HTTPX vs Requests vs AIOHTTP

The Python ecosystem offers several excellent HTTP clients to choose from. Three of the most popular ones are HTTPX, Requests, and AIOHTTP. While all three libraries allow you to make HTTP requests in Python, they have some key differences that developers should consider when picking one for their project. This article provides an in-depth comparison of HTTPX, Requests, and AIOHTTP.

Overview of HTTPX

HTTPX is a relatively new Python library that aims to provide a powerful and enjoyable HTTP client. It was created by Tom Christie, who is also the author of the Django REST Framework.

Some of the key features of HTTPX include:

Supports both HTTP/1.1 and HTTP/2
Synchronous and asynchronous APIs
Automatic JSON decoding
Connection pooling
HTTP Proxies
Browser-style CookieJar support
Timeout configuration
Automatic retries

The API design of HTTPX is inspired by Requests. However, HTTPX builds on top of Requests and provides an improved developer experience.

To install HTTPX:

pip install httpx

Here is an example of making a simple GET request with HTTPX:

import httpx

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

And here is an example of a POST request:

import httpx

data = {‘key‘: ‘value‘}

response = httpx.post(‘https://httpbin.org/post‘, data=data)
print(response.json())

One of the advantages of HTTPX is that it supports both synchronous and asynchronous code in the same API. To make an async request, you use Python‘s async/await syntax:

import httpx

async def main():
  async with httpx.AsyncClient() as client:
    response = await client.get(‘https://example.com‘)
    print(response.text)

asyncio.run(main())

This makes HTTPX a great choice for developers looking for async HTTP capabilities.

Overview of Requests

Requests is a simple yet powerful HTTP library for Python. It has been around for many years and is currently one of the most downloaded Python packages.

Some key features of Requests include:

Support for HTTP methods like GET, POST, PUT, DELETE, HEAD, etc.
Automatic encoding of JSON data
Support for cookies and authentication
Connection pooling and session support
Timeout handling
Automatic decompression
Proxy and SSL Certificate verification

To install Requests:

pip install requests

Here is how you would make a GET request with Requests:

import requests

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

And here is how to send a POST request:

import requests

data = {‘key‘: ‘value‘}
response = requests.post(‘https://httpbin.org/post‘, data=data)
print(response.json())

One limitation of Requests is that it only supports synchronous code, unlike HTTPX. Requests is ideal for basic HTTP needs, but for more advanced use cases, a library like HTTPX may be preferable.

Overview of AIOHTTP

AIOHTTP is a performant asynchronous HTTP client for Python that is built on top of the asyncio library. It allows making HTTP requests in async code using the async/await syntax.

Some key features of AIOHTTP:

Async request support with async/await
Connection pooling
HTTP pipelining
Support for websockets
Browser-like cookie jar
Proxy support
Client authentication
Timeout handling

To install AIOHTTP:

pip install aiohttp

Here is an example of making an async GET request with AIOHTTP:

import aiohttp
import asyncio

async def main():
  async with aiohttp.ClientSession() as session:
    async with session.get(‘https://example.com‘) as response:
      print(await response.text())

asyncio.run(main())

And here is an async POST request:

import aiohttp
import asyncio

async def main():

  data = {‘key‘: ‘value‘}

  async with aiohttp.ClientSession() as session:
    async with session.post(‘https://httpbin.org/post‘, json=data) as response:
       print(await response.text())

asyncio.run(main())

A key advantage of AIOHTTP is the performance benefits of asynchronous code. However, it only supports async programming, unlike HTTPX.

Detailed Comparison

Now that we have provided an overview of all three libraries, let‘s dig deeper into comparing their features and performance.

Async Support

HTTPX has both a synchronous and asynchronous API. It allows you to write non-blocking asynchronous code using async/await.
Requests is synchronous only. There is no async API.
AIOHTTP is asynchronous only and meant for use in async applications.

HTTP/2 Support

HTTPX has built-in support for HTTP/2, the latest version of HTTP.
Requests and AIOHTTP do not support HTTP/2.

Automatic Encoding/Decoding

All three libraries automatically encode request data like JSON.
HTTPX and Requests automatically decode response data like JSON, saving developers effort.
AIOHTTP does not automatically decode response data.

Performance

AIOHTTP is the clear winner when it comes to performance thanks to its async-only design. Benchmarks show it‘s faster than both HTTPX and Requests for concurrent workloads.
HTTPX is faster than Requests in most test scenarios.
For typical API requests, performance differences may not be noticeable. But under load, AIOHTTP shines.

Ease of Use

Requests has the simplest API of the three and is beginner friendly.
HTTPX builds on top of Requests and has a straightforward API as well.
AIOHTTP requires understanding async/await, so has a slightly steeper learning curve.

Features

HTTPX has the most complete feature set – HTTP/2, proxies, connection pooling, cookie jar, timeouts, retries.
Requests supports all major HTTP features except HTTP/2.
AIOHTTP focuses mainly on async requests but still supports advanced features like websockets.
For advanced use cases like distributed scraping, HTTPX or AIOHTTP may be preferable over Requests.

Community/Adoption

Requests has the largest community and is the most popular choice for Python developers.
HTTPX adoption is growing rapidly. AIOHTTP also has strong adoption among Python async developers.

Recommendations

For basic API requests and simple HTTP needs, Requests is ideal and beginner friendly.
For advanced HTTP features and performance gains from asynchronous code, choose HTTPX or AIOHTTP.
If building an app that must scale and perform well under load, AIOHTTP is likely the best option.
For both sync and async capabilities in one library, HTTPX shines.
For complex scraping/crawling projects, HTTPX or AIOHTTP will provide more advanced options.
For large-scale distributed web scraping, AIOHTTP tends to be the most recommended choice.

So in summary:

Requests – Simple synchronous HTTP for beginners
HTTPX – Advanced sync/async HTTP client
AIOHTTP – High-performance asynchronous HTTP

Think about your specific needs and use case when deciding between these excellent Python HTTP libraries. All three are great options that will handle most web scraping and API integration tasks.