JSON metafield values limited to 128KB
Starting in API version 2026-04, writes to JSON-type metafields will be capped at 128KB (down from the current 2MB limit), which will break write operations for apps that store larger JSON payloads unless they were already using JSON metafields before April 1, 2026 (grandfathered at 2MB) or granted an exception.
What to do: Audit all metafield writes (via metafieldsSet, REST /metafields.json endpoints, or Customer Account/Storefront API mutations) that use the 'json' type and ensure values stay under 128KB for any app not already using JSON metafields before April 1, 2026. Apps with existing JSON metafields will be grandfathered at the current 2MB limit, but new apps needing larger values must request an exception via Shopify's provided form before relying on values >128KB.
metafieldsSetMetafieldsSetInputMetafieldsSetPayloadmetafieldDefinitionCreateMetafield.type/admin/api/2026-04/metafields.json/admin/api/2026-04/.../metafields/{metafield_id}.jsonGraphQL Admin API · Admin REST API · Customer Account API · Storefront API
