ER diagram PNG export · free, no watermark

Free Mermaid ER Diagram to PNG Converter

Paste Mermaid ER diagram code, preview the schema, and export a clean PNG for data-model docs, migration pull requests, and database coursework. Renders locally in your browser — no upload, no watermark.

No signup · No watermark · Local browser rendering · Transparent background · 1x / 2x / 4x output

Paste or edit Mermaid code

Replace the sample below, or load another example.

Load example

Paste Mermaid code here. Preview and export load locally in your browser.

erDiagram
  SOURCE ||--o{ EXPORT : renders
  SOURCE ||--o{ TEMPLATE : uses
  SOURCE {
    string code
  }
  EXPORT {
    string file
  }
  TEMPLATE {
    string style
  }

Live previewSample preview · Clean Docs

Render & export

Export controls activate after your diagram renders locally.

ERD

Mode

Default renderNative MermaidOptimized exportStyled download

Export style

Clean DocsGitHub READMEGitHub DarkTransparent DocsWarm Editorial✦ ProWhiteboard Sketch✦ ProAurora Noir✦ ProBlueprint✦ ProChampagne✦ ProEmerald Suite✦ ProEditorial✦ Pro

Scale

1x2x4x

Or exact width, e.g. 1200px wide

Output: White · comfortable padding

Size: calculated after render

Filename: mermaid-erd-white-2x.png

Why export ER diagrams as images

ER diagrams live where Mermaid code is least likely to run — database docs, migration pull requests, and PDFs for class. A PNG export keeps the cardinality notation readable for every reader, no plugin or local install required.

Schema documentation

Put the rendered data model next to the tables it describes so every reader sees the same relationships.

Migration pull requests

Attach the before-or-after ER diagram so reviewers check cardinality changes without rendering code.

Database coursework

Export a clean PNG or PDF of the model for assignments and study notes — no dedicated CASE tool needed.

ER diagram syntax worth knowing

The sample above is a complete little schema. Cardinality is written on both sides of the relationship line — the left symbol says how many of the left entity, the right how many of the right.

Cardinality symbols

||: Exactly one
o|: Zero or one
}o: Zero or more (crow's foot)
}|: One or more

Entities and relationships

A ||--o{ B : verb: Relationship: one A to many B
ENTITY { ... }: Attribute block for the entity
string name: An attribute with its type
PK / FK / UK: Key annotations on their own line

ER diagram export checklist

Dense schema?

Crow's-foot notation is small — export at 2x so relationship symbols stay unambiguous in docs.

Overview first?

Drop attribute blocks and keep entity names for a lighter overview diagram, then export that.

Vector docs?

SVG keeps entity text sharp in platforms that accept vector; PNG is the compatible default.

Mermaid to PNG converter Mermaid to SVG converter Mermaid cheat sheet

FAQ

Questions about this Mermaid export workflow

How do I convert a Mermaid ER diagram to PNG?+

Paste your erDiagram code into the editor above, check the preview, then click Download PNG. Background, theme, and scale are set before export, and everything runs locally in your browser.

Can I export an ER diagram with a transparent background?+

Yes. Pick a transparent background preset before downloading — the exported PNG has real alpha transparency.

Is the ER diagram export free and watermark-free?+

Yes. All exports — PNG, SVG, JPG, WebP, PDF — are free, with no signup and no watermark.

Why does my exported ER diagram look cramped?+

Long attribute lists widen entities and squeeze relationship labels. Shorten attribute names, drop types, or export at 2x so notation stays readable.

Which format is best for ER diagrams?+

PNG at 2x for docs and PRs, SVG for zoomable design docs, PDF for print submissions.