Web clients crates

Library	Description	Best Use Cases
reqwest	A full-featured HTTP client built on hyper, with async support and great ergonomics. Uses Tokio	General-purpose HTTP client for REST APIs.
surf	A simple and flexible HTTP client that supports async with pluggable backends like async-std.	Lightweight and simpler HTTP use cases.
isahc	A synchronous and async HTTP client powered by curl. It implements an internal event loop so it doesn’t depend on Tokio or async-std	For cURL enthusiasts and native platform support.
ureq	A lightweight, synchronous-only HTTP client designed for simplicity.	Simple APIs, fast startup, no async.
hyper	A low-level, fast HTTP implementation. Great as a foundation for building custom clients. It depends on Tokio.	When full control over HTTP is needed.
actix-web	A powerful framework for building web applications, including REST APIs and servers, built on the Actix actor system.	Creating high-performance servers or REST APIs.
ureq	A lightweight, synchronous-only HTTP client designed for simplicity.	Simple APIs, fast startup, no async.

reqwest

reqwest is the most popular HTTP client in the Rust ecosystem, offering both sync and async APIs. It is built on hyper, but provides a much simpler interface:

• Async and blocking support.
• Built-in JSON (de)serialization (serde integration).
• Automatic gzip/deflate compression handling.
• Proxy support and advanced configuration options.
• TLS support (with rustls or native openssl).

Code Example:

use reqwest::Client;
 
#[tokio::main]
async fn main() -> Result<(), reqwest::Error> {
    let client = Client::new();
    let response = client
        .get("https://api.github.com/repos/rust-lang/rust")
        .header("User-Agent", "my-app")
        .send()
        .await?;
 
    let json: serde_json::Value = response.json().await?;
    println!("Repo Info: {}", json);
    Ok(())
}

surf

It is designed to be a flexible and simple HTTP client for async-first applications and to work with various runtimes runtimes (e.g., tokio, async-std):

• Async support with pluggable backends.
• Middleware support (e.g., retries, logging).
• Native serde integration for JSON. Code Example:

use surf;
 
#[async_std::main]
async fn main() -> surf::Result<()> {
    let mut response = surf::get("https://api.github.com/repos/rust-lang/rust")
        .header("User-Agent", "my-app")
        .await?;
    let json: serde_json::Value = response.body_json().await?;
    println!("Repo Info: {}", json);
    Ok(())
}

isahc

A curl-based HTTP client for both async and sync use, emphasizes native platform compatibility (leveraging libcurl):

• Async and blocking support.
• Full cURL features (e.g., advanced proxy options, cookie handling).
• Low-level control over HTTP requests.

Code Example:

use isahc::prelude::*;
 
fn main() -> Result<(), isahc::Error> {
    let response = isahc::get("https://api.github.com/repos/rust-lang/rust")?;
    println!("{}", response.text()?);
    Ok(())
}

ureq

A minimalistic, synchronous-only HTTP client., designed for simplicity and fast startup time:

• Synchronous only (no async support).
• Small binary size and minimal dependencies.

Code Example:

use ureq::Agent;
 
fn main() -> Result<(), ureq::Error> {
    let agent = Agent::new();
    let response = agent
        .get("https://api.github.com/repos/rust-lang/rust")
        .set("User-Agent", "my-app")
        .call()?;
 
    let json: serde_json::Value = response.into_json()?;
    println!("Repo Info: {}", json);
    Ok(())
}

hyper

A low-level HTTP implementation for building HTTP clients and servers, most other clients (reqwest, surf) are built on top of hyper:

• Fine-grained control over HTTP requests.
• High performance and low-level optimizations.
• Async-only API.

Code Example:

use hyper::{Client, Uri};
use hyper::body::HttpBody as _;
 
#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let client = Client::new();
    let uri = "https://api.github.com/repos/rust-lang/rust".parse::<Uri>()?;
 
    let mut response = client.get(uri).await?;
    while let Some(chunk) = response.body_mut().data().await {
        println!("Chunk: {:?}", chunk?);
    }
    Ok(())
}

Actix-web

actix-web is a web framework for building HTTP servers and REST APIs. It’s built on top of the Actix actor model and is known for its excellent performance and flexibility:

• High performance (benchmark leader for Rust web frameworks).
• Actor-based model for managing state and concurrency.
• Middleware support for logging, authentication, compression, and more.
• Built-in support for WebSockets and HTTP/2.
• Type-safe routing and request extraction.

Feature	reqwest	surf	isahc	ureq	hyper	actix-web
Async Support	✅	✅	✅	❌	✅	✅
Sync Support	✅	❌	✅	✅	❌	❌
Built-in JSON Support	✅	✅	✅	✅	❌	✅
Lightweight	❌	✅	✅	✅	❌	❌
Low-Level Control	❌	❌	✅	❌	✅	❌
Middleware Support	✅	✅	❌	❌	❌	✅
Ideal for Servers	❌	❌	❌	❌	✅	✅
Ideal for Clients	✅	✅	✅	✅	✅	❌

Tower

Tower is a middleware framework for building reusable, composable components for HTTP services and clients. Tower is often used to add features like retries, timeouts, rate limiting, or authentication to hyper-based clients or servers.