hashbrown vs bevy_ecs

Short answerBy steady daily use, hashbrown is bigger: 8,927,960 real downloads a day against 25,237 for bevy_ecs (353.8x). 2,468 crates depend on hashbrown and 775 on bevy_ecs. hashbrown last shipped 6 months ago, bevy_ecs 19 days ago.

hashbrown

Widely used

Widely used and steady.

2,468 crates depend on it; no release in the last 90 days, so its count is all steady use.

A Rust port of Google's SwissTable hash map

bevy_ecs

Established

Established and gaining.

775 crates depend on it; downloads don't spike on releases.

Bevy Engine's entity component system

hashbrownbevy_ecs · 100% = that crate's normal quiet day, so a spike to 300% is triple its usual traffic

Every number, side by side

Same window, same method	hashbrown	bevy_ecs
Real downloads a day	8,927,960	25,237
Crates that depend on it	2,468	775
Last release	0.17.1, 6 months ago	0.20.0, 19 days ago
Trend vs the field	-4%	+16%
Release-window share	0.0%	10.1%
Downloads in the window	793,966,067	2,338,523
All-time downloads	2,826,725,908	9,944,577
Versions published	56	65
License	MIT OR Apache-2.0	MIT OR Apache-2.0
MSRV	1.85.0	1.95.0
First published	Oct 29, 2018	Aug 10, 2020

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 (hashbrown, 2,468 dependents): more eyes, more answered questions, and you may already have it in your tree.
Check the release dates against your own pace: hashbrown 6 months ago, bevy_ecs 19 days ago.

Also in this space

ahashWidely usedA non-cryptographic hash function using AES-NI for high performance1,968,676 a day, 2,097 dependents nohash-hasherEstablishedAn implementation of `std::hash::Hasher` which does not hash at all324,114 a day, 224 dependents smallvecWidely used'Small vector' optimization: store up to a small number of items on the stack3,868,589 a day, 4,345 dependents eitherWidely usedThe enum `Either` with variants `Left` and `Right` is a general purpose sum type with two cases3,049,603 a day, 1,488 dependents

Compare 4 of them side by side →

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 26, 2026). Raw crates.io counts include CI and bots and run high (why); the method is from our 90-day study.

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Art: Nicholas Roerich, Nag Lake (1925). Public domain, via Wikimedia Commons.