Crates / derive_arbitrary
Rust crate · real downloads · data Oct 24, 2026
derive_arbitrary downloads, and should you depend on it?
Derives arbitrary traits crates.io · docs · repository
Owned on crates.io by fitzgen, nagisa, Manishearth · alternatives · is it still maintained?
Few direct dependents and losing ground.
derive_arbitrary: only 9 crates name it directly; most of its downloads come in through der and arbitrary; small bumps on release days (1.18x the baseline).
How this verdict is decided (4 rules)
- Usage: crates.io reverse dependencies (crates that list it as a dependency): 10,000+ = foundational, 1,000+ = widely used, 100+ = established, under 100 = few direct dependents.
- Direction: the median quiet day in the last 30 days of the window against the first 30, read against the median tracked crate (the whole field moved +39% from late summer to October, so a raw trend says nothing). 10%+ ahead of the field = gaining; 10%+ behind = losing ground; otherwise steady. Steady with no release in 2+ years = quiet for years.
- Release spikes: the median release-window day against the quiet-day baseline: under 1.15x = no spike, 1.15x to 1.3x = small bumps, 1.3x or more = jumps on release days.
- Release recency: days since the newest version that was not yanked, from crates.io publish times.
release window (release day + next day)quiet dayquiet-day median · download the 89 days as CSV
The numbers in one paragraphderive_arbitrary got 31,326,825 crates.io downloads from Jul 27, 2026 to Oct 23, 2026. 3% of them landed within 2 days of one of its 1 release. On the other 87 quiet days it got a median of 369,897 a day, about 2,589,279 a week. Capping release days at that baseline leaves 31,193,036 release-adjusted downloads for the window.
What this means if you're choosing a dependency
- You rarely add this one yourself. Only 9 crates name it directly; its downloads arrive through der, arbitrary, aws-smithy-eventstream.
- Actively released. 1.5.0 shipped 18 days ago (Oct 6, 2026).
- Fit check: license MIT OR Apache-2.0, edition 2021, needs Rust 1.71.0 or newer (from the latest version's manifest).
- Compare it by the baseline, not the raw count. 3% of its 31,326,825 downloads in the window landed within 2 days of a release; the steady number is 369,897 a day.
Alternatives that do a similar job
Crates that share its crates.io category or keywords, most similar first. Each line is the crate's own description, then how it compares on the same data.
Its place in the dependency graph
Built on derive_arbitrary
3 of the 1000 crates we track depend on it directly (biggest first).
derive_arbitrary builds on
Tracked crates its latest version (1.5.0) depends on.
What the chart says
- Weekend quiet days ran at 55% of weekday quiet days (216,824 vs 391,801). A dip that deep is the signature of work-week CI pipelines and developers building on weekdays.
- Biggest day: 538,018 on Oct 22, 2026, a quiet day with no release nearby.
Every number
| All-time downloads | 130,273,591 (rank #788 on crates.io by all-time downloads) |
| Downloads in the window | 31,326,825 (Jul 27, 2026 to Oct 23, 2026, 89 days) |
| Within 2 days of a release | 873,583 (2.8%) |
| Quiet-day median (baseline) | 369,897 a day; weekdays 391,801, weekends 216,824 |
| Release-adjusted downloads | 31,193,036 (release-window days capped at the baseline) |
| Baseline rank | #783 of the 1000 crates we track |
| Quiet-day trend | +21% raw, -12% against the median tracked crate (+39%) |
| Releases in the window | 1 |
| Versions published, ever | 34 |
| Latest version | 1.5.0, published Oct 6, 2026 (license MIT OR Apache-2.0, edition 2021, MSRV 1.71.0) |
| First published | Oct 13, 2018 |
| Reverse dependencies | 9 |
Releases in the window
Each one opens a 2-day release window on the chart.
| Version | Published | Downloads that version got (lifetime) |
|---|---|---|
| 1.5.0 | Oct 6, 2026 | 890,187 |
How we compute this
crates.io counts every download, including CI runners, mirrors and bots that fetch each new version, so raw counts run high (why, in The Manual). We split the last 89 days into release windows (the day a version of derive_arbitrary was published, plus the next day) and quiet days, and use the median quiet day as the baseline: an upper bound on steady use, never a head count. The method and data come from our study of 90 days of crates.io data from 69 crates, featured in This Week in Rust #674; check any crate live with the real-downloads checker.
Badge for your README
Maintainers can show the baseline in a README. It is optional, updates when we refresh the data, and links back here. Preview, then copy:
README, light
README, dark
Publishing a crate of your own? How to publish a Rust crate to crates.io, step by step.
Categories
Sources
- Daily downloads: crates.io API, /crates/derive_arbitrary/downloads (last 90 days, all versions), fetched Oct 24, 2026.
- Versions and publish times: crates.io API, /crates/derive_arbitrary/versions, same fetch.
- Reverse dependencies: crates.io reverse dependencies, same fetch. Dependency edges between tracked crates: each crate's default version, crates.io API.
- Fetched politely (one request every 2 seconds, identified User-Agent) per the crates.io data access policy. Data is crates.io's; the release-window split, baseline and verdict rules are ours, CC BY 4.0.
Up next
Next in testing: Next in Testing by real downloads: 365,882 a day, 2 dependents. Few direct dependents and steady.rstest_macrosRust crate. Rust fixture based test framework. It use procedural macro to implement fixtures and table based tests. Real use: 366K downloads a day on quiet days; 2...Read it next →Also worth your time