Axum vs Actix Web for a Rust API

Axum and Actix Web are both async Rust web frameworks, both parse requests with typed extractors, and both run on Tokio-based runtimes. The differences that matter in practice are how each one schedules work, how application state reaches handlers, and which middleware ecosystem it plugs into.

What each framework owns

Axum keeps its own surface small. Its documentation lists routing with a macro-free API, extractors, a simple error handling model, and minimal response boilerplate. It does not have its own middleware system; it uses tower::Service, which in its words means Axum "gets timeouts, tracing, compression, authorization, and more, for free" from the tower and tower-http ecosystem.

Actix Web comes with a larger first-party ecosystem. Its crate documentation lists HTTP/1.x and HTTP/2, streaming and pipelining, client and server WebSockets, and middlewares such as Logger, Session, and CORS. Several of these live in companion crates, not in actix-web itself: sessions in actix-session, CORS in actix-cors, and the current WebSocket API in actix-ws. Extractors provide "type-safe request information access" through impl FromRequest, and middleware implements Actix Web's own Service and Transform traits.

Concurrency and runtime model

Axum states that it is "designed to work with tokio and hyper," and that runtime and transport independence is not a goal. A typical Axum binary starts with #[tokio::main], which by Tokio's documentation uses the multi-threaded runtime with one worker thread per CPU by default.

Actix Web uses a worker model. Its server documentation describes HttpServer starting several HTTP workers, each with its own application instance. The workers API documentation gives the default count as the value of std::thread::available_parallelism(), which can differ from the number of physical cores. Two consequences follow:

• A handler that blocks its thread stops that worker from processing new requests. Blocking work belongs off the request path in either framework.
• Application state initialized inside the closure passed to HttpServer::new is local to each worker. State shared by every worker, such as a database pool, is created outside the closure and moved in; web::Data uses Arc internally.

In Axum, shared state is attached to the router with with_state and read with the State extractor.

Ecosystem and library fit

If the libraries you plan to use are tower layers or services (rate limiting, timeouts, tracing, auth middleware written for tower), Axum uses them directly. Actix Web middleware implements different traits, so tower middleware does not plug in without an adapter; the Actix ecosystem has its own crates for common needs, such as actix-cors.

Both work with the same database crates. sqlx, SeaORM, and Diesel do not depend on the web framework.

Deployment constraints

Both compile to a native server binary. Deployment constraints come from the target platform, the database, and TLS termination rather than from the framework choice.

What Better Fullstack generates

The two commands below differ only in --rust-web-framework:

bun create better-fullstack@latest my-api \
  --ecosystem rust \
  --rust-web-framework axum \
  --database postgres \
  --rust-orm sqlx

bun create better-fullstack@latest my-api \
  --ecosystem rust \
  --rust-web-framework actix-web \
  --database postgres \
  --rust-orm sqlx

Add --dry-run to preview either project without writing files. Both create a Cargo workspace with one crate, crates/server, on the stable toolchain with rustfmt and clippy. Both use the default tracing logging and anyhow with thiserror for errors, create one PgPool with up to five connections at startup, and expose a single GET /health route that reports whether a connection can be acquired. The server entry in crates/server/src/main.rs is where they differ:

The generated output is a starting point with clear limits:

• /health is the only route. There are no queries, models, migrations, or tests in either project.
• The server reads DATABASE_URL at startup and panics if it is unset. .env.example lists the variables; copy it to .env, which dotenvy loads.
• Some options are Axum-only. --rust-auth tower-sessions is rejected with Actix Web because the generated session middleware is wired for Axum.

These are generated projects, not runtime-verified deployments. Run cargo build and cargo test and exercise a real query before committing to either.

Decision table

Related guides

• Axum + PostgreSQL + SeaORM guide
• Rust backend pack

For a Go or Python service instead, read Gin vs Echo vs Fiber or FastAPI vs Django.