optimizers · google

Adafactor

Sublinear-memory adaptive optimizer using factored second-moment estimates. Standard for large T5-style training.

Verify

What this registry has checked

Quarantine. We hold the publisher’s own published hash for these weights and have recorded it against this entry. We have not downloaded and hashed the weights ourselves, so the hash is the publisher’s claim, not our measurement.

Weight file SHA-256	2a7bde699fe52d545de584b5473f8b2bb3ea1919feb9951a907cade8c58849d7

Re-check this yourself → Source → Full record →

What is recorded

Publisher	google
Origin	United States
Licence	Apache-2.0
Pulls recorded here	72,003

Elsewhere in the registry

All optimizers → Browse with filters → What will run on my hardware? →

Registry record as of 2026-06-06. Identity, licence and parameter count are properties of a release and do not move; tier can, and the verify link above re-checks it against the live registry rather than this page.