JSON metafield values limited to 128KB

When using API version 2026-04 or later, JSON type metafield writes will be limited to 128KB. Limits for all other metafield types remain unchanged (current limits). All apps that use JSON fields (prior to April 1st, 2026), will be grandfathered at the current 2MB limit. Large metafield values continue to be readable by all API versions, including future versions.

Large JSON metafield negatively impact storefront performance—particularly when multiple large values are loaded together, which can result in tens of megabytes of data being fetched for a single page. Our goal is to accommodate all current use cases while preventing performance issues stemming from extremely large values.

If you are a new app and believe you have a use case that requires >128KB JSON fields, please fill out this form to request access. Additional limits will be granted on a case by case basis.

Note: Initially, this change limited metafields to 16KB. After feedback from our developer community, we've revised those limits to accommodate more use cases and updated this post.