Crates / Compare / arrayvec vs ndarray
Rust crates side by side · data Oct 24, 2026
arrayvec vs ndarray
Short answerBy steady daily use, arrayvec is bigger: 1,733,744 real downloads a day against 354,525 for ndarray (4.9x). 1,215 crates depend on arrayvec and 2,985 on ndarray. arrayvec last shipped 4 months ago, ndarray 9 months ago.
arrayvec
Widely usedWidely used and steady.
1,215 crates depend on it; no release in the last 90 days, so its count is all steady use.
A vector with fixed capacity, backed by an array (it can be stored on the stack too). Implements fixed capacity ArrayVec and ArrayString.
ndarray
Widely usedWidely used and steady.
2,985 crates depend on it; no release in the last 90 days, so its count is all steady use.
An n-dimensional array for general elements and for numerics. Lightweight array views and slicing; views support chunking and splitting.
arrayvecndarray · 100% = that crate's normal quiet day, so a spike to 300% is triple its usual traffic
How they relate
- Often used together: 1 tracked crate depend on both (rust_decimal). They are not always either/or.
Every number, side by side
| Same window, same method | arrayvec | ndarray |
|---|---|---|
| Real downloads a day | 1,733,744 | 354,525 |
| Crates that depend on it | 1,215 | 2,985 |
| Last release | 0.7.8, 4 months ago | 0.17.2, 9 months ago |
| Trend vs the field | +2% | +1% |
| Release-window share | 0.0% | 0.0% |
| Downloads in the window | 157,353,540 | 32,180,592 |
| All-time downloads | 640,435,610 | 136,801,822 |
| Versions published | 57 | 93 |
| License | MIT OR Apache-2.0 | MIT OR Apache-2.0 |
| MSRV | 1.51 | 1.64 |
| First published | May 19, 2015 | Dec 20, 2015 |
Which to pick
- 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 (ndarray, 2,985 dependents): more eyes, more answered questions, and you may already have it in your tree.
- Check the release dates against your own pace: arrayvec 4 months ago, ndarray 9 months 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.
Up next
Another comparison: Same method, same window. Widely used and steady vs widely used and steady.smallvec vs arrayvecRead it next →Also worth your time