CharField must have max_length set (DBR007)

Django’s CharField does not strictly require max_length for PostgreSQL and SQLite backends, but omitting it creates a UX problem: CharField renders as an <input> element in forms and the admin, while TextField renders as a <textarea>. A CharField without max_length gives users a single-line input with no length constraint — misleading and inconsistent. If there’s no meaningful max length, a TextField should be used instead.

This rule enforces that every CharField in a Django model has max_length set to a non-None value.

Wrong:

from django.db import models


class MyModel(models.Model):
    # CharField without max_length — renders as <input> with no constraint
    name = models.CharField()

    # CharField with max_length=None — same problem
    title = models.CharField(max_length=None)

Correct:

from django.db import models


class MyModel(models.Model):
    # CharField with explicit max_length
    name = models.CharField(max_length=255)

    # Or use TextField if no max length is needed
    description = models.TextField()

Rationale

• CharField renders as <input type="text"> in Django forms and admin — a single-line field

• TextField renders as <textarea> — a multi-line field

• A CharField without max_length gives users an <input> that accepts unlimited text, which is confusing

• If the field truly has no length constraint, TextField is the appropriate choice