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What is

The standard library in Rust is much smaller than in Python or Go, for example. Those languages come with "batteries included" support for things like HTTP(S), JSON, timezones, random numbers, and async IO. Rust, on the other hand, gets things like that from the ecosystem and the Cargo package manager. But with almost 100 thousand crates to choose from, a common complaint from new Rust developers is that they don't know where to start, which crates they ought to use, and which crates they ought to trust. This list attempts to answer those questions.

See also which takes a more automated approach (ordering crates by number of downloads) and also has an excellent search function.


Developer tools for working with Rust projects.

Use Case Recommended Crates
Toolchain Management

Install, manage, and upgrade versions of rustc, cargo, clippy, rustfmt and more.


The official Rust linter.

Lint your crate releases for semantic versioning violations.

Code Formatting

The official Rust code formatter.

Cross Compilation

Seamless cross-compiling using Docker containers.

Easily cross-compile using Zig as the linker.

Managing Dependencies

Adds 'cargo upgrade' and 'cargo set-version' commands to cargo

Finds dependencies that have available updates

Check dependencies for reported security vulnerabilities

Lists licenses of all dependencies

Enforce policies on your code and dependencies.


Faster, better test runner

Snapshot testing with inline snapshot support


criterion [docs]
Statistically accurate benchmarking tool for benchmarking libraries

divan [docs]
Simple yet powerful benchmarking library with allocation profiling

Tool for benchmarking compiled binaries (similar to unix time command but better)


Execution flamegraph generation

dhat [docs]
Heap memory profiling

cargo-show-asm [docs]
Print the generated assembly for a Rust function

Debugging Macros

Rust Analyzer also allows you to expand macros directly in your editor

Allows you to inspect the code that macros expand to

Release Automation

Helper for publishing new crate versions.

Release Rust crates from CI with a Release PR.

Continuous Integration

rust-toolchain (github action)
Github action to install Rust components via rustup

rust-cache (github action)
Github action to cache compilation artifacts and speed up subsequent runs.

install-action (github action
GitHub Action for installing development tools (mainly from GitHub Releases).


Very commonly used crates that everyone should know about


General purpose

Use Case Recommended Crates
Random numbers

rand [docs]
De facto standard random number generation library split out from the standard library

Time & Date

Unfortunately there is no clear answer as to which is best between time and chrono.
Evaluate for yourself between these two, but be resassured that both are trusted and well-maintained.

time [docs]
A smaller, simpler library. Preferrable if covers your needs, but it's quite limited in what it provides.

chrono [docs]
The most comprehensive and full-featured datetime library, but more complex because of it.

Serialization (JSON, YAML, etc)

See here for supported formats.

serde [docs]
De facto standard serialization library. Use in conjunction with sub-crates like serde_json for the specific format that you are using.

Regular Expressions

regex [docs]
De facto standard regex library. Very fast, but does not support fancier features such as backtracking.

fancy-regex [docs]
Use if need features such as backtracking which regex doesn't support


uuid [docs]
Implements generating and parsing UUIDs and a number of utility functions

Temporary files

tempfile [docs]
Supports both temporary files and temporary directories

Gzip (de)compression

flate2 [docs]
Uses a pure-Rust implementation by default. Use feature flags to opt in to system zlib.

Insertion-ordered map

indexmap [docs]
A HashMap that seperately keeps track of insertion order and allows you to efficiently iterate over its elements in that order

Stack-allocated arrays

arrayvec [docs]
Arrays that are ONLY stack-allocated with fixed capacity

smallvec [docs]
Arrays that are stack-allocated with fallback to the heap if the fixed stack capacity is exceeded

tinyvec [docs]
Stack allocated arrays in 100% safe Rust code but requires items to implement the Default trait.

HTTP Requests

See the HTTP section below for server-side libraries

reqwest [docs]
Full-fat HTTP client. Can be used in both synchronous and asynchronous code. Requires tokio runtime.

ureq [docs]
Minimal synchronous HTTP client focussed on simplicity and minimising dependencies.

Error Handling

Crates for more easily handling errors

Use Case Recommended Crates
For applications

anyhow [docs]
Provides a boxed error type that can hold any error, and helpers for generating an application-level stack trace.

color-eyre [docs]
A fork of anyhow that gives you more control over the format of the generated error messages. Recommended if you intend to present error messages to end users. Otherwise anyhow is simpler.

For libraries

See also: Designing error types in Rust

thiserror [docs]
Helps with generating boilerplate for enum-style error types.


Crates for logging. Note that in general you will need a seperate crate for actually printing/storing the logs

Use Case Recommended Crates
Text-based logging

tracing [docs]
Tracing is now the go-to crate for logging.

log [docs]
An older and simpler crate if your needs are simple and you are not using any async code.

Structured logging

tracing [docs]
Tracing is now the go-to crate for logging.

slog [docs]
Structured logging

Language Extensions

General purpose utility crates that extend language and/or stdlib functionality.

Use Case Recommended Crates
Lazy static variable initialization

The core functionality of once_cell is now included in the standard library with the remaining parts on track to be stabilised in future.

once_cell [docs]
Newer crate with more ergonomic API. Should be preferred for all new projects.

lazy_static [docs]
Older crate. API is less convenient, but crate is stable and maintained.

Iterator helpers

itertools [docs]
A bunch of useful methods on iterators that aren't in the stdlib

Macro helpers

syn [docs]
Parse rust source code

quote [docs]
Quasi quoting rust (useful for interpolating generated code with literal code)

paste [docs]
Concatenating and manipulating identifiers

Safe type casts

bytemuck [docs]

zerocopy [docs]


bitflags [docs]
Strongly typed bitflag types


For low-level interaction with the underling platform / operating system

Use Case Recommended Crates
Memory mapping files

memmap2 [docs]
The older memmap crate is unmaintained.


libc [docs]
Bindings for directly calling libc functions.

Windows (OS)

windows [docs]
The official Microsoft-provided crate for interacting with windows APIs

winapi [docs]
Older binding to the windows APIs. Unofficial, but more complete than windows-rs

*nix (OSs)

nix [docs]
Bindings to the various *nix system functions. (Unix, Linux, MacOS, etc.)

Math / Scientific

The num crate is trusted and has a variety of numerical functionality that is missing from the standard library.

Use Case Recommended Crates
Abstracting over different number types

num-traits [docs]
Traits like Number, Add, etc that allow you write functions that are generic over the specific numeric type

Big Integers

num-bigint [docs]
It's not the fastest, but it's part of the trusted num library.

rug [docs]
LGPL licensed. Wrapper for GMP. Much faster than num-bigint.

Big Decimals

rust_decimal [docs]
The binary representation consists of a 96 bit integer number, a scaling factor used to specify the decimal fraction and a 1 bit sign.

Sortable Floats

ordered-float [docs]
Float types that don't allow NaN and are therefore orderable. You can also use the total_cmp method from the standard library like .sort_by(|a, b| a.total_cmp(&b)).

Linear Algebra

nalgebra [docs]
General-purpose linear algebra library with transformations and statically-sized or dynamically-sized matrices. However it supports only vectors (1d) and matrices (2d) and not higher-dimensional tensors.

ndarray [docs]
Less featureful than nalgebra but supports arbitrarily dimensioned arrays


polars [docs]
Similar to the Pandas library in Python but in pure Rust. Uses the Apache Arrow Columnar Format as the memory model.

datafusion [docs]
Apache DataFusion is an in-memory query engine that uses Apache Arrow as the memory model

FFI / Interop

Crates that allow Rust to interact with code written in other languages.

Use Case Recommended Crates

bindgen [docs]
Generate Rust bindings to C libraries

cbindgen [docs]
Generate C bindings to Rust libraries


cxx [docs]
Safe C++ <-> Rust interop by generating code for both sides.


pyo3 [docs]
Supports both calling python code from Rust and exposing Rust code to Python


napi [docs]
is a framework for building pre-compiled Node.js addons in Rust.

neon [docs]
Slower than napi, but also widely used and well-maintained


rutie [docs]
Supports both embedding Rust into Ruby applications and embedding Ruby into Rust applications


objc [docs]
Interop with the Objective-C runtime


jni [docs]
Implement Java methods for JVM and Android in Rust. Call Java code from Rust. Embed JVM in Rust applications.


mlua [docs]
Bindings to Lua 5.4, 5.3, 5.2, 5.1 (including LuaJIT)


flutter_rust_bridge [docs]
Works with Dart with or without Flutter


rustler [docs]
Safe Rust bridge for creating Erlang NIF functions


Crates that provide implementations of cryptographic algorithms. This section attempts to list the best crates for the listed algorithms, but does not intend to make recommendations for the algorithms themselves.

Use Case Recommended Crates
Password Hashing

For more algorithms, see Rust Crypto Password Hashes.

argon2 [docs]

scrypt [docs]

bcrypt [docs]

General Purpose Hashing

For more algorithms, see Rust Crypto Hashes.

sha2 [docs]

sha1 [docs]

md-5 [docs]

AEAD Encryption

For more algorithms, see Rust Crypto AEADs.

aes-gcm-siv [docs]

aes-gcm [docs]

chacha20poly1305 [docs]


rsa [docs]

Digital Signatures

For more algorithms, see Rust Crypto Signatures.

ed25519 [docs]
Use in conjunction with the ed25519-dalek crate.

ecdsa [docs]

dsa [docs]

Certificate Formats

For more formats, see Rust Crypto Formats.

der [docs]

pem-rfc7468 [docs]

pkcs8 [docs]

x509-cert [docs]


rustls [docs]
A portable pure-rust high-level implementation of TLS. Implements TLS 1.2 and higher.

native-tls [docs]
Delegates to the system TLS implementations on windows and macOS, and uses OpenSSL on linux.

See also (click to open)

webpki [docs]
X.509 Certificate validation. Builds on top of ring.

ring [docs]
Fork of BoringSSL. Provides low-level cryptographic primitives for TLS/SSL


subtle [docs]
Utilities for writing constant-time algorithms

zeroize [docs]
Securely erase memory


TCP, HTTP, GRPc, etc. And the executors required to do asynchronous networking.

Async Foundations

To do async programming using the async-await in Rust you need a runtime to execute drive your Futures.

Use Case Recommended Crates
General Purpose Async Executors

tokio [docs]
The oldest async runtime in the Rust ecosystem and still the most widely supported. Recommended for new projects.

futures-executor [docs]
A minimal executor. In particular, the block_on function is useful if you want to run an async function synchronously in codebase that is mostly synchronous.

See also (click to open)

async-std [docs]
A newer option that is very similar to tokio. Its API more closely mirrors the std library, but it doesn't have as much traction or ecosystem support as Tokio.

Async Utilities

futures [docs]
Utility functions for working with Futures and Streams

async-trait [docs]
Provides a workaround for the lack of language support for async functions in traits


glommio [docs]
Use if you need io_uring support. Still somewhat experimental but rapidly maturing.


HTTP client and server libraries, as well as lower-level building blocks.

Use Case Recommended Crates
Types & Interfaces

http [docs]
The `http` crate doesn't actually contain an HTTP implementation. Just types and interfaces to help interoperability.

Low-level HTTP Implementation

hyper [docs]
A low-level HTTP implementation (both client and server). Implements HTTP/1, and HTTP/2. Works best with the tokio async runtime, but can support other runtimes.

HTTP Client

reqwest [docs]
Full-fat HTTP client. Can be used in both synchronous and asynchronous code. Requires tokio runtime.

ureq [docs]
Minimal synchronous HTTP client focussed on simplicity and minimising dependencies.

See also (click to open)

surf [docs]
Client that uses the async-std runtime rather than the tokio runtime. Not well maintained.

HTTP Server

axum [docs]
A minimal and ergonomic framework. An official part of the tokio project. Recommend for most new projects.

actix-web [docs]
A performance focussed framework. All Rust frameworks are fast, but choose actix-web if you need the absolutely maximum performance.

See also (click to open)

rocket [docs]
Has an excellent API and a solid implementation. However development has been intermittent.

poem [docs]
Automatically generates OpenAPI definitions.

warp [docs]
Very similar to axum but with a quirkier API. This is a solid framework, but you should probably prefer Axum unless you particularly like the API

tide [docs]
Similar to Axum, but based on async-std rather than tokio

GraphQL Server

async-graphql [docs]
A high-performance graphql server library that's fully specification compliant. Integrates with actix-web, axum, poem, rocket, tide, warp.


This section includes libraries for you to use just websockets. However note that many of the HTTP server frameworks in the section above also support websockets

Use Case Recommended Crates

tungstenite [docs]
Low-level crate that others build on

General Purpose

tokio-tungstenite [docs]
If you are using the tokio executor

async-tungstenite [docs]
If you are using the async-std executor


Use Case Recommended Crates
General Purpose

tonic [docs]
gRPC over HTTP/2 with full support for asynchronous code. Works with tokio


SQL Databases

The multi-database options (SQLx and Diesel) are generally quite good, and worth considering even if you only need support for a single database.

Use Case Recommended Crates
Multi Database

sqlx [docs]
Works with Postgres, MySQL, SQLite, and MS SQL.
Supports compile time checking of queries. Async: supports both tokio and async-std.


diesel [docs]
Has excellent performance and takes an approach of strict compile time guarantees. The main crate is Sync only, but diesel-async provides an async connection implementation.

sea-orm [docs]
Built on top of sqlx (see above). There is also a related sea-query crate that provides a query builder without full ORM functionality.


tokio-postgres [docs]
Postgres-specific library. Performs better than SQLx


mysql_async [docs]
Has a poorly designed API. Prefer SQLx or Diesel for MySQL


rusqlite [docs]
Provides a sync API to SQLite + provides access to advanced sqlite features.


tiberius [docs]
MS SQL specific library. Has better support for advanced column types than SQLx.


diesel-oci [docs]
Diesel backend and connection implementation for oracle databases

oracle [docs]
Rust bindings to ODPI-C

Other Databases

Use Case Recommended Crates

redis [docs]


mongodb [docs]


elasticsearch [docs]

Rocks DB

rocksdb [docs]


cassandra-protocol [docs]
Low-level Cassandra protocol implementation.

cdrs-tokio [docs]
High-level async Cassandra driver.


Use Case Recommended Crates
Connection pool

deadpool [docs]
A dead simple async pool for connections and objects of any type.


Argument Parsing

See argparse-benchmarks-rs for a full comparison of the crates mentioned here and more.

Use Case Recommended Crates

clap [docs]
Ergonomic, battle-tested, includes the kitchen sink, and is fast at runtime. However compile times can be slow

See also (click to open)

bpaf [docs]
Faster compile times than clap while still being featureful. But still has some rough edges, and the API can be confusing at times.


lexopt [docs]
Fast compile times, fast runtime, pedantic about correctness. API is less ergonomic

pico-args [docs]
Fast compile times, fast runtime, more lax about correctness. API is more ergonomic


Helpers that are often useful when implementing CLIs

Use Case Recommended Crates

High-performance globbing that allows multiple globs to be evaluated at once

Directory walking

Basic recursive filesystem walking.

Recursive filesystem walking that respects ignore files (like .gitignore)

File watching

notify [docs]
Watch files or directories and execute a function when they change

Terminal Rendering

For fancy terminal rendering and TUIs. The crates recommended here work cross-platform (including windows).

Use Case Recommended Crates
Coloured Output

termcolor [docs]
Cross-platform terminal colour output

Progress indicators

indicatif [docs]
Progress bars and spinners


ratatui [docs]
A high-level TUI library with widgets, layout, etc.

crossterm [docs]
Low-level cross-platform terminal rendering and event handling

Interactive prompts

inquire [docs]
Ask for confirmation, selection, text input and more


Data Structures

Use Case Recommended Crates

parking_lot [docs]
std::sync::Mutex also works fine. But Parking Lot is faster.

Atomic pointer swapping

arc-swap [docs]
Useful for sharing data that has many readers but few writers

Concurrent HashMap

See conc-map-bench for comparative benchmarks of concurrent HashMaps.

dashmap [docs]
The fastest for general purpose workloads

flurry [docs]
Particularly good for read-heavy workloads.


See communicating-between-sync-and-async-code for notes on when to use async-specific channels vs general purpose channels.

crossbeam-channel [docs]
The absolute fastest channel implementation available. Implements Go-like 'select' feature.

flume [docs]
Smaller and simpler than crossbeam-channel and almost as fast

tokio [docs]
Tokio's sync module provides channels for using in async code

postage [docs]
Channels that integrate nicely with async code, with different options than Tokio

Parallel computation

rayon [docs]
Convert sequential computation into parallel computation with one call - `par_iter` instead of `iter`



Use Case Recommended Crates

gtk4 [docs]
Rust bindings to GTK4. These are quite well supported, although you'll often need to use the C documentation.

relm4 [docs]
A higher-level library that sits on top of gtk4-rs

Web-based GUI

tauri [docs]
Electron-like web-based UI. Except it uses system webviews rather than shipping chromium, and non-UI code is written in Rust rather than node.js

dioxus [docs]
A very nice API layer that has Tauri, Web, and TUI renderers. A native renderer is coming soon.

Immediate Mode Native GUI

egui [docs]
Immediate-mode UI. Lots of widgets. The most useable out of the box if your needs are simple and you don't need to customise of the look and feel

Retained Mode Native GUI

iced [docs]
Retained mode UI with a nice API. It's useable for basic apps, but has a number of missing features including multiple windows, layers, and proper text rendering.

Inspired by Xilem, Leptos and rui, floem is currently more complete than any of them for native UI. Used by the Lapce text editor.

Fairly complete with sophisticated layout and text layout, but has yet to make a stable release.

See also (click to open)

The replacement for Druid based on the more interoperable Vello and Glazier crates. However, it's currently not complete enough to be usable.

Dioxus-based GUI framework using Skia for rendering.

slint [docs]
Possibly the most complete rust-native UI library. But note that it's dual GPL3/commercial licensed.

druid [docs]
Druid is a relatively mature alternative to Iced/Slint, however it has been discontinued in favour of Xilem so it's use for new projects is discouraged.

High performance framework used in the Zed text editor. Currently macOS only.

Makepad has a strong focus on performance and minimising bloat but is consequently less feature complete in areas such as accessibility and system integration.


cushy [docs]

rui [docs]

concoct [docs]

kas [docs]

Window creation

winit [docs]
The defacto standard option. Uses an event loop based architecture. Widely used and should probably be the default choice.

tao [docs]
A fork of winit by the Tauri project which adds support for things like system menus that desktop apps need.

A new competitor to winit based on the old druid-shell. Has a callback that may be better than the event loop architecture for some tasks. Doesn't yet have a stable release.

Specialized window creation library targetting windows to be embedded in other applications (e.g. DAW plugins)

2D Renderers

femtovg [docs]
OpenGL based. Offers a simple API. Probably the easiest to get started with.

skia-safe [docs]
Bindings to the Skia C++ library. The most complete option with excellent performance. However, it can be difficult to get it to compile.

WGPU based and uses cutting edge techniques to render vector paths using the GPU. Still somewhat immature and hasn't yet put out a stable release.

vger [docs]
A simpler WGPU based option which is less innovative but currently more stable than vello.

webrender [docs]
OpenGL based. Mature with production usage in Firefox but documentation and OSS maintenance are lacking.

UI layout

taffy [docs]
Supports Flexbox and CSS Grid algorithms.

morphorm [docs]
Implements it's own layout algorithm based on Subform layout

Text layout

cosmic-text [docs]
Full text layout including rich text and support for BiDi and non-latin scripts. The best option for now.

Another very accomplished text layout library used by Druid/Xilem.


accesskit [docs]
Allows you to export a semantic tree representing your UI to make accessible to screen readers and other assistive technologies


arboard [docs]
A fork of rust-clipboard that supports copy and pasting of both text and images on Linux (X11/Wayland), MacOS and Windows.

File Dialogs

rfd [docs]
Platform-native open/save file dialogs. Can be used in conjunction with other UI libraries.

Game Development

Use Case Recommended Crates
Game Engines

bevy [docs]
An ECS based game engine, good for 3D but also capable of 2D.

fyrox [docs]
An OOP-focused game engine with 3D and 2D support and a full GUI scene editor.

ggez [docs]
A simpler option for 2d games only.

macroquad [docs]
A simple and easy to use 2d game library, great for beginners.

3D Math

glam [docs]
Fast math library optimised for game development use cases