blank=True vs null=True in Django

null=True

• Database layer.
• Column accepts SQL NULL.
• Django represents the absence of a value as Python None.
• Needed for non-string fields (e.g., DateField, ForeignKey) to store "no value."
• Indexes and unique constraints treat NULL as distinct from every non-null value.

blank=True

• Validation layer.
• Model and form validation permit an empty value on save or submit.
• For strings, the actual value stored is '' (empty string) unless null=True is also set.
• Has no effect on the SQL schema.

Common patterns

• String fields: → empty string stored, forms omit value.