crates.io crate name checker and rules

A brand claims its name on crates.io as a crate name, crates.io/crates/yourname. Our check looks up that crate. How our checks work

CostFree
Name lengthUp to 64 characters
CharactersLetters, numbers, - _
You needA GitHub account, verified email
Holds the nameYour first published version
Checked 25 Oct 2026, 07:24 UTCSources [2, 3, 5]

What can a crates.io crate name contain?

ASCII letters, numbers, hyphens and underscores, starting with a letter, up to 64 characters.

CharacterAllowed?Where
Letters a to zYesFirst character must be a letter
Numbers 0 to 9YesNot first
Hyphen (-), underscore (_)YesNot first
Anything elseNo

Capitals don't make a new name, and my-crate and my_crate count as the same crate. Reserved names, such as the Windows file name nul, are rejected.[1, 3]

How do you publish your first crate on crates.io?

Log in with GitHub, verify your email, then publish with Cargo.

  1. Check the name above, with GitHub and the .com.
  2. Log in to crates.io with a GitHub account, which is required for now, and verify your email in Account Settings.
  3. Create an API token and run cargo login.
  4. Add a description to Cargo.toml, which crates.io requires, then run cargo publish.[1, 2]

What should you know before you claim a crates.io name?

Names are first come, first served, and a publish is permanent.

FactWhat it means
One crate per nameOnce a name is taken, no other crate can use it
PermanentA version can't be overwritten, and its code can't be deleted
YankingStops new projects depending on a version; it deletes nothing
DeletingAllowed only under set conditions, such as within 72 hours of publishing
No squattingContent that exists only to reserve a name is prohibited

Sources [2, 4]

What if someone already has your crates.io name?

Ask the owner. The crates.io team won't transfer a crate without the current owner's approval, and follows the Rust Foundation's legal decisions on trademark issues.[4]

Which platforms should you claim with crates.io?

GitHub, npm, PyPI, X and the .com.

Checks crates.io, GitHub, npm, PyPI, X and the .com in one search.

Sources (5)

  1. PrimaryCargo Book: The manifest format
  2. PrimaryCargo Book: Publishing on crates.io
  3. PrimaryCargo Book: Registry index, name restrictions
  4. Primarycrates.io: Usage policy, read from its source file in the crates.io repository
  5. PrimaryZero To 1000's platform catalog: crates.io cost and rules