Reports / Crate Census / Issue 1
Crate Census · issue 1 · crates.io data Oct 24, 2026
How much of crates.io's top 1000 is release-day traffic?
Short answerAcross the 1000 most-downloaded Rust crates (Jul 27, 2026 to Oct 23, 2026), the median crate that shipped a release got 3.4% of its downloads within 2 days of a release. 625 shipped nothing in the window, so every download they got was steady use. 6 got a quarter or more of their downloads in release windows, and on those the raw count overstates steady use the most. Weekend quiet days ran at 58% of weekdays for the median crate.
Biggest release-day jumps
Median release-window day against the quiet-day median: how hard downloads jump when a version ships (mirrors, CI caches and bots fetching the new version).
| Crate | Release-day lift | Share in release windows | Releases |
|---|---|---|---|
| pulldown-cmark | 2.0x | 4% | 1 |
| memmap2 | 1.9x | 4% | 1 |
| smol_str | 1.9x | 4% | 1 |
| yoke | 1.7x | 4% | 1 |
| crypto-bigint | 1.7x | 2% | 1 |
| inout | 1.7x | 10% | 3 |
| aws-credential-types | 1.6x | 4% | 1 |
| ctutils | 1.6x | 5% | 3 |
| equivalent | 1.6x | 3% | 1 |
| webpki-root-certs | 1.6x | 5% | 2 |
| webpki-roots | 1.6x | 5% | 2 |
| const_format_proc_macros | 1.5x | 2% | 1 |
What it means
- Compare crates by the quiet-day baseline, not the raw count. A crate with frequent releases looks bigger than it is; every crate page shows both.
- Quiet crates are not dead crates. 625 of the top 1000 shipped nothing for 90 days and still get millions of downloads: most are finished building blocks. Issue 2 looks at them.
Method
Daily downloads per crate (all versions) from the crates.io API for the top 1000 crates by all-time downloads, fetched one request every 2 seconds. A release window is the day a version was published and the next day; every other day is quiet; the quiet-day median is the baseline. Same method as our study (This Week in Rust #674).
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