Django to ER Diagram

How it works

1. Copy your models.py — one app or several pasted together.
2. Paste it into the editor (or drop the .py file on the page). Django is detected automatically.
3. Each model becomes a table with Django’s implicit id; ForeignKey and OneToOneField become foreign keys and ManyToManyField becomes a junction table.
4. Arrange, hide tables, then export PNG/SVG or convert to Mermaid/DBML.

Example

Paste Django models like these:

from django.db import models

class Author(models.Model):
    name = models.CharField(max_length=100)

class Post(models.Model):
    title = models.CharField(max_length=200)
    author = models.ForeignKey(Author, on_delete=models.CASCADE)

…and you get Author and Post with a relation from Post.author_id → Author.id. Try it with your own →

Guide

Django doesn't have a schema file to paste — your models live in Python — but it can print the exact SQL it will run, and that's what you paste here. Run python manage.py sqlmigrate yourapp 0001 for the initial migration (or sqlmigrate on whichever migration created the tables you care about) and copy the output: CREATE TABLE "blog_post" with an REFERENCES "blog_author"("id") foreign key, ready to diagram.

Tips for multi-app projects:

• Run sqlmigrate once per app and paste the outputs together — tables link up by their foreign keys automatically, and the appname_ table prefixes keep the diagram readable.
• ForeignKey becomes a drawn relation; ManyToManyField shows up as the auto-created join table (blog_post_tags) exactly as Django builds it.
• If you use django-extensions, the graph_model command is an alternative — but its output is static dot/PyGraphviz, while this renders interactive and exportable.

The result reflects the real database Django creates — including the id BIGINT PRIMARY KEY auto-pk and _id column naming — so it's accurate even when your models use custom db_table or related_name tricks.

Why use it

• Private: everything runs in your browser — nothing is uploaded or stored on a server.
• Straight from code: no migration run and no database needed — models.py is read as it is.
• Interactive: drag tables, auto-arrange, hide noise, add notes, and manually link columns.
• Export a high-res PNG, vector SVG, or the schema as Mermaid / DBML / PlantUML code.
• Free & open source — no account, no sign-up.

FAQ

How do I make an ER diagram from Django models?

Paste your models.py into the editor. Each model becomes a table, and ForeignKey, OneToOneField and ManyToManyField become relations.

Can I see all apps at once?

Yes. Paste the models from several apps together — relations written as "app.Model" are linked by the model name.

Are the table names the real database names?

A model that sets db_table in its Meta is shown under that name. Otherwise the table is labelled with the model class name (Post), because Django’s default app_post name depends on the app label, which models.py doesn’t contain. For the exact tables, paste the output of python manage.py sqlmigrate yourapp 0001 instead.

Is my schema uploaded anywhere?

No. Everything runs locally in your browser — your schema is never uploaded to or stored on any server.

Is it free?

Yes. It is completely free and open source, with no account or sign-up required.

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