Auth0 Support Center - Meaning of the Action Limitation of 32kB for user_metadata and app

Meaning of the Action Limitation of 32kB for user_metadata and app_metadata Per Session

Feb 20, 2026

Overview

This article explains the meaning of the 32kb Action Limitation for user_metadata and app_metadata per session.

Applies To

Solution

The app_metadata and user_metadata have a combined size limit of 16MB as noted in the document Size limits and Storage of Metadata Field Names and Data types.

It is only possible to save (persist) 32kB of data to each of the user_metadata and app_metadata per execution of an Action (as in, each metadata field can save 32kB each).