Design your database
right in the browser
YourERD is a free online ERD editor — nothing to install, nothing to pay for. Connect two entities and the foreign keys are written for you. When the model is ready, export it as MySQL DDL.
No sign-up needed to start drawing. Create an account only if you want your work stored on the server.
What you get
The notation and the deliverables that real data modelling actually needs.
Foreign keys, written for you
Draw a relationship and the child entity gets a foreign key column derived from the parent's primary key. Delete the relationship or change its type and the columns are cleaned up to match.
Barker notation
Identifying, non-identifying and optional relationships are drawn with solid and dashed halves plus crow's-foot markers. One-to-one and one-to-many are supported, and each half of a line can be configured on its own.
MySQL DDL export
Download your diagram as a MySQL 8 CREATE TABLE script, complete with primary and foreign key constraints and comments carried over from your logical names.
Physical and logical names
Keep a technical column name and a human-readable one side by side. Both show up on the diagram, and the logical name becomes a comment in the generated DDL.
Editing that stays out of the way
Double-click to rename or retype in place, box-select several entities and move them together. Auto-layout, undo/redo and sticky notes are all built in.
Share with a link
Generate a link and other people can watch the same diagram update in real time. Revoke it whenever you like.
Saving and exporting
Signed in, your work is saved every five seconds and kept in a list of diagrams. You can also download a JSON file or a PNG image at any point.
Three steps is all it takes
From an empty canvas to a DDL file.
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Add an entity
Hit Add Entity in the left sidebar and a table appears on the canvas. Double-click the name or any column to edit it in place.
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Connect them
Drag from a connection point on the entity border to another entity, then pick the relationship type. Foreign key columns are created at that moment.
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Export the DDL
Press the SQL button in the toolbar at the bottom right and a MySQL DDL file is downloaded. Need a picture instead? Export a PNG.
Learn from a working model
Open e-commerce, blog, and HR samples, then see the rule each relationship is meant to protect.
E-commerce orders
Resolve many-to-many order items, and separate the current catalogue from a historical purchase.
Blog publishing
Separate authors, posts, comments, and tags, with the constraint a tag bridge needs in practice.
HR reporting lines
Model department assignment and an optional employee self-reference without losing sight of cycles.
Let Claude draw it
YourERD ships an MCP (Model Context Protocol) server. Connect it to Claude Code and a structure you describe in words becomes a diagram.
Model in plain language
Ask for something like "draw the order domain for an e-commerce site" and the entities and relationships appear. Everything it makes stays fully editable in the browser.
One command to connect
Issue a personal token from the MCP menu in the editor and paste the single command it gives you. No repository to clone, no config file to hand-edit.
Prompt examples included
The prompt guide collects worked examples for common situations, so you can see what phrasing produces what model.
Frequently asked questions
Do I need an account?
No. You can draw diagrams and export SQL or PNG without signing in. An account is only needed to store diagrams on the server and manage several of them in a list. Without one, export a JSON file to keep your work.
Which databases can it generate DDL for?
MySQL 8 today. UUID becomes CHAR(36), and VARCHAR, CHAR and DECIMAL carry the size you specify. Primary keys, foreign keys, NOT NULL and UNIQUE constraints are emitted along with comments from your logical names. Tables are ordered parents-first and wrapped in a foreign key check toggle to cope with circular references.
How are foreign keys generated?
A column is derived from the parent entity's primary key. The flags depend on the relationship type: an identifying relationship puts the column in the child's primary key and marks it NOT NULL, a non-identifying one keeps it out of the primary key but still NOT NULL, and an optional one allows NULL. Deleting the relationship — or the parent entity — cleans the generated columns up again.
Can other people see my diagram?
Only if you create a share link. Anyone holding that link can watch the diagram in real time; editing stays with the owner for now, so link visitors are read-only. Revoking a link cuts off access through it immediately.
What does it cost?
Nothing. Part of the running cost is covered by ads shown on the site.
Is there a Korean version?
Yes. The 🌐 button in the editor's top bar switches between English and Korean, and the manual and guides have Korean editions too.
Start drawing
Nothing to install. No card details.