Crates / Compare / async-std vs tokio
Rust crates side by side · data Oct 24, 2026
async-std vs tokio
Short answerasync-std is discontinued; new code should use tokio, or smol if you liked async-std's design. By steady daily use, tokio is bigger: 3,098,313 real downloads a day against 138,341 for async-std (22.4x). 1,903 crates depend on async-std and 78,796 on tokio. async-std last shipped 14 months ago, tokio 3 days ago.
async-std
Widely usedWidely used and losing ground.
1,903 crates depend on it; no release in the last 90 days, so its count is all steady use.
Deprecated in favor of `smol` - Async version of the Rust standard library
tokio
FoundationalFoundational and steady.
78,796 crates depend on it; downloads jump on release days (1.4x the baseline).
An event-driven, non-blocking I/O platform for writing asynchronous I/O backed applications.
async-stdtokio · 100% = that crate's normal quiet day, so a spike to 300% is triple its usual traffic
How they relate
- Often used together: 6 tracked crates depend on both (quinn, sqlx-core, sqlx-macros-core, deadpool-runtime, io-lifetimes, backoff). They are not always either/or.
Every number, side by side
| Same window, same method | async-std | tokio |
|---|---|---|
| Real downloads a day | 138,341 | 3,098,313 |
| Crates that depend on it | 1,903 | 78,796 |
| Last release | 1.13.2, 14 months ago | 1.54.1, 3 days ago |
| Trend vs the field | -23% | -8% |
| Release-window share | 0.0% | 11.6% |
| Downloads in the window | 11,792,005 | 272,815,137 |
| All-time downloads | 98,131,835 | 1,101,468,563 |
| Versions published | 38 | 201 |
| License | Apache-2.0 OR MIT | MIT |
| MSRV | 1.63 | 1.85 |
| First published | May 30, 2019 | Jul 1, 2016 |
Which to pick
- Pick async-std if only to maintain existing code: async-std's README now says it has been discontinued and recommends smol.
- Pick tokio if any new project.
- Bottom line: async-std is discontinued; new code should use tokio, or smol if you liked async-std's design. (checked against each project's docs, Oct 24, 2026)
- Downloads tell you what is common, not what fits. Each crate's own description above says what it is for; when the jobs differ, pick by the job.
- When both fit, prefer the one more crates depend on (tokio, 78,796 dependents): more eyes, more answered questions, and you may already have it in your tree.
- Check the release dates against your own pace: async-std 14 months ago, tokio 3 days ago.
Also in this space
Method
Real downloads = the median day with no release that day or the day before, from the crates.io API (Jul 27, 2026 to Oct 23, 2026). Raw crates.io counts include CI and bots and run high (why); the method is from our 90-day study. People search for this pair: Google suggests "async-std vs tokio".
Up next
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