libuv vs Tokio
Which should you use? A side-by-side look at what each one does, who it suits, what it costs, how hard it is to set up, and where each falls short.
Open source · MIT
A C library that handles asynchronous input/output and event loops across operating systems.
Open source · MIT
A Rust library for writing fast, reliable async programs that handle networking and timers.
The short answer
Choose libuv if you need…
- Developers building networked or I/O-heavy software in C or a language with C bindings
- Teams that need the same async I/O code to run on Linux, macOS, and Windows
- Projects that want a stable ABI across major versions, per its versioning policy
- People studying how event loops work, using its tests and benchmarks as examples
Choose Tokio if you need…
- Rust developers building network servers or clients
- Teams writing async services that handle many connections at once
- Developers who want an established, widely referenced async runtime
- Projects that need timers, scheduling, and async I/O in one package
Side-by-side
| libuv | Tokio | |
|---|---|---|
| Type | Library | Library |
| Price | Free and open source | Free and open source |
| Licence | MIT | MIT |
| GitHub stars | 27.3k | 33.6k |
| Setup difficulty | Advanced | Advanced |
| How you get it | Install with a package manager | Install with a package manager |
| Main language | C | Rust |
| Last code update | 6 days ago | 6 days ago |
What each one is
libuv
libuv is a C library that lets programs do many input and output tasks at once without waiting on each one, such as networking, file system work, and child processes. It hides differences between operating systems behind one interface. It was mainly built for Node.js and is also used by projects like Julia and uvloop.
Tokio
Tokio is a runtime for the Rust programming language that lets a program do many slow tasks at once, such as handling network connections, without waiting on each one in turn. It provides a task scheduler, an interface to the operating system's event queue for I/O, and asynchronous TCP and UDP sockets. Developers use it as the foundation for network servers and other async applications.
Best for
libuv
- Developers building networked or I/O-heavy software in C or a language with C bindings
- Teams that need the same async I/O code to run on Linux, macOS, and Windows
- Projects that want a stable ABI across major versions, per its versioning policy
- People studying how event loops work, using its tests and benchmarks as examples
Tokio
- Rust developers building network servers or clients
- Teams writing async services that handle many connections at once
- Developers who want an established, widely referenced async runtime
- Projects that need timers, scheduling, and async I/O in one package
Strengths
libuv
- Cross-platform support across epoll, kqueue, IOCP, and event ports, per the README feature list
- MIT licensed with documented semantic versioning and a stated stable ABI across majors
- Widely used in production by Node.js and other projects, and tests double as API examples
Tokio
- The README describes it as built on Rust's ownership and type system to reduce bugs and ensure thread safety
- Includes a multithreaded, work-stealing task scheduler and an OS-level event reactor
- Has an active community, a Discord server, a tutorial site, and a discussions page
Not ideal for
libuv
- Non-programmers or people looking for an end-user application, since it is a low-level library
- Projects that want a high-level framework with built-in HTTP routing or ORM features, since libuv provides lower-level primitives
Tokio
- Non-Rust programmers, since it is a Rust library and requires Rust to use
- People who only need synchronous code, because the async model adds complexity without benefit for simple scripts
- Anyone needing a binary app; the README describes a library with no downloadable binaries
Trade-offs
libuv
- As a C library, it requires comfort with C build tooling and memory management
- Some platform features need extra setup, such as AIX file system events needing a non-default package and z/OS needing ZOSLIB
- The README notes some third-party learning resources may be out of date
Tokio
- Requires learning Rust and async concepts, which the README does not teach in depth
- Some features are enabled through Cargo feature flags, so you must choose which to include (the example uses full)
- The README lists a minimum supported Rust version (currently 1.85) that you must meet
Getting started
libuv
Install with Homebrew (HEAD build)
brew install --HEAD libuvInstall with vcpkg
./vcpkg install libuvTokio
Add tokio to Cargo.toml with full features
tokio = { version = "1.54.1", features = ["full"] }Frequently asked questions
What is the difference between libuv and Tokio?
libuv: A C library that handles asynchronous input/output and event loops across operating systems. Tokio: A Rust library for writing fast, reliable async programs that handle networking and timers. libuv suits developers building networked or i/o-heavy software in c or a language with c bindings, while Tokio suits rust developers building network servers or clients.
Are libuv and Tokio free?
libuv: Free and open source. Tokio: Free and open source.
Is libuv or Tokio more popular?
Tokio has more GitHub stars (33.6k) than libuv (27.3k). Popularity isn't the same as fit — check which one matches your use case above.
What are other alternatives to libuv and Tokio?
Other options people compare them with include Workerman.
Built from our catalogue entries for both products: open-source details come from each project's README (AI-assisted, refreshed weekly) and GitHub data; AI-tool details are editorial. Spotted something wrong? Let us know from either product's page.