Free ERD Maker Online — No Signup, No Watermark, No Software to Install

Most online ERD tools require creating an account, add watermarks to exports, or limit you to one free diagram. This free browser-based ERD maker has none of those restrictions. Write entity-relationship diagrams from text, render them instantly, export PNG or SVG — completely free, no email, no watermark.

Here is what you get, exactly as it is, no asterisks.

What You Get — Free, No Strings

The complete feature list, with zero paid upgrade paths:

Feature	Available	Notes
Text-to-ERD rendering	Yes	Mermaid erDiagram syntax, renders in under 1 second
Unlimited entities	Yes	No cap on tables or relationships
All relationship types	Yes	One-to-one, one-to-many, many-to-many, zero-or-one
Crow's foot notation	Yes	Standard ERD notation, auto-rendered
Export PNG	Yes	No watermark, 2x resolution
Export SVG	Yes	Scalable, editable in design tools
Auto-render while typing	Yes	Updates live as you type (500ms debounce)
Account required	No	Open and use immediately
Watermark	No	Never
Data uploaded to server	No	Everything runs in your browser
Cloud save	No	Copy your ERD code to save it locally

Getting Started in Under 2 Minutes

Open the ERD maker. You will see a pre-loaded example (a USERS/ORDERS/PRODUCTS schema) already rendered in the preview pane. Here is the syntax at a glance:

erDiagram
    ENTITY_NAME {
        datatype column_name KEY_TYPE
    }

    ENTITY_ONE ||--o{ ENTITY_TWO : "relationship label"

Entity block: Define each table with its column names and data types. Add PK after a column to mark it as the primary key, FK for foreign keys.

Relationship line: Connect two entities with a notation that describes the cardinality:

Notation	Meaning	Reads as
||--||	One-to-one	Exactly one to exactly one
||--o{	One-to-many (optional)	One to zero or more
||--|{	One-to-many (required)	One to one or more
}o--o{	Many-to-many (optional)	Zero or more to zero or more
}|--|{	Many-to-many (required)	One or more to one or more

Clear the example code, paste your own table definitions, and click Render. Your ERD appears in the right pane.

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Why No Signup Is a Real Advantage

Requiring a signup — even a free one — creates friction that costs you time and privacy:

• No email to verify. Some tools send a confirmation email before you can use them at all — that is a 2-5 minute interruption for a simple diagram.
• No password to create and store. With hundreds of accounts across tools, security hygiene matters. This tool does not add to that list.
• No profile data collected. Your name, email, and usage patterns stay off their servers because there is no account system.
• No subscription email list. No signup means no marketing emails about plan upgrades.
• Works in guest/incognito mode. Ideal for corporate environments where creating personal accounts on external tools is not allowed.

The only thing you lose without an account: cloud save. Your ERD diagram is not automatically saved between sessions. Copy the ERD code text and save it in a local file, your git repository, or a note-taking app before closing the tab.

Browser-Based — No Software, No OS Restrictions

The ERD maker runs entirely in your browser — there is nothing to install and it works on every operating system:

Platform	Works?	Best browser
Windows 10 / 11	Yes	Chrome, Edge, Firefox
macOS (any version)	Yes	Chrome, Safari, Firefox
Linux (Ubuntu, Fedora, Arch)	Yes	Chrome, Firefox
Chromebook / ChromeOS	Yes	Chrome (native)
iPad / iOS tablet	Yes (limited)	Safari — editor works, export works
Android tablet	Yes (limited)	Chrome — typing on mobile keyboard is small

The tool is optimized for desktop use — the split-pane editor/preview layout works best on screens wider than 768px. On mobile, the editor and preview stack vertically, which is functional but less convenient for longer schemas.

No network connection is required after the initial page load. The diagram rendering happens locally — you could turn off your wifi and the tool would still work.

Saving Your ERD Diagrams

Since there is no cloud save, here are the recommended ways to preserve your work:

Option 1: Save the code to a file
Copy the ERD code from the left pane and save it as a .txt or .mmd file on your local machine. You can paste it back in the next time you open the tool.

Option 2: Commit to a git repository
Save the .mmd file in your project repository. Mermaid code is plain text — it diffs cleanly in pull requests. GitHub and GitLab also render Mermaid in README files, so your diagram can serve as living documentation.

Option 3: Export the image
Export as PNG or SVG and save the image file. This preserves the visual output but not the editable code — if you need to update the diagram later, you will need to rewrite it from scratch.

Option 4: Embed in Notion or Confluence
Both Notion and Confluence support Mermaid code blocks. Paste the ERD code into a Mermaid block in your documentation platform and it renders in place.

Frequently Asked Questions

Is there a limit to how many ER diagrams I can create?

No limit. Create as many diagrams as you need. Since there is no account system, we do not track usage. Each time you open the tool you start fresh — save your ERD code between sessions to continue working on a diagram.

Does the ERD diagram look professional enough for client work?

Yes. The tool renders standard crow's foot notation with clean, readable output suitable for documentation, README files, design reviews, and client presentations. The exported PNG is 2x resolution (HiDPI), and the SVG export is infinitely scalable. The output is equivalent in quality to paid tools like dbdiagram.io.

Can I use this tool offline?

Once the page is loaded in your browser, the diagram rendering works offline. The initial page load requires an internet connection (to load the Mermaid rendering library). After that, you can work without network access. Exports also work offline since they use browser-native canvas and SVG generation.

What data types can I use in the entity definitions?

Any text you enter as a data type is displayed in the diagram — the tool does not validate against specific database data types. You can use standard SQL types (int, varchar, decimal, datetime, boolean) or any custom labels that make sense for your diagram (string, number, date, text, etc.). The data type label is informational only.