Rust crates side by side · data Oct 24, 2026

uuid vs ulid

Short answerBy steady daily use, uuid is bigger: 2,553,829 real downloads a day against 200,012 for ulid (12.8x). 22,614 crates depend on uuid and 819 on ulid. uuid last shipped 1 day ago, ulid 3 months ago.

uuid

Foundational

Foundational and steady.

22,614 crates depend on it; downloads don't spike on releases.

A library to generate and parse UUIDs.

ulid

Established

Established and steady.

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

a Universally Unique Lexicographically Sortable Identifier implementation

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

How they relate

ulid is built on uuid: its latest version lists uuid as a dependency, so every ulid build also downloads uuid. Part of uuid's count is ulid's.

Every number, side by side

Same window, same method	uuid	ulid
Real downloads a day	2,553,829	200,012
Crates that depend on it	22,614	819
Last release	1.29.0, 1 day ago	3.0.0, 3 months ago
Trend vs the field	-1%	-8%
Release-window share	13.7%	0.0%
Downloads in the window	226,213,858	17,372,052
All-time downloads	912,704,599	43,205,376
Versions published	101	27
License	Apache-2.0 OR MIT	MIT
MSRV	1.89.0	not set
First published	Nov 11, 2014	Jun 8, 2017

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 (uuid, 22,614 dependents): more eyes, more answered questions, and you may already have it in your tree.
Check the release dates against your own pace: uuid 1 day ago, ulid 3 months ago.

Also in this space

const-oidEstablishedConst-friendly implementation of the ISO/IEC Object Identifier (OID) standard as defined in ITU X.660, with...2,079,241 a day, 160 dependents derEstablishedPure Rust embedded-friendly implementation of the Distinguished Encoding Rules (DER) for Abstract Syntax...1,514,408 a day, 378 dependents hashbrownWidely usedA Rust port of Google's SwissTable hash map8,927,960 a day, 2,468 dependents synFoundationalParser for Rust source code8,378,886 a day, 18,848 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 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 "uuid vs ulid".