Custom Fields are a method of customizing your products in ways that aren't necessarily included by default in BigCommerce. They're often used to provide options for things like material, color, size, etc. In this article, we'll talk about some of the limits for custom fields, and our recommendations for when you bump up against them.
BigCommerce only supports up to 250 characters per custom field. This is enough for the vast majority of our clients; however if this is too low for what you're trying to use custom fields for, there are a few options. You can utilize metadata fields to add more information to a given product, or you can search for alternative app-based solutions supported by BigCommerce.
Additionally, a given product can only have 200 custom fields at a given time.