Free Mermaid tools
Single-purpose tools for the jobs around a Mermaid diagram: exporting it, checking it, and generating it from data you already have. Each one runs in your browser, with no sign-up.
Export Mermaid
Turn Mermaid code into an image, a document or a file another tool can edit.
- Mermaid to PNG Convert Mermaid to PNG online, free and without signing up. Paste your code, set an exact width or height, and download the image. Works for every diagram type.
- Mermaid to SVG Convert a Mermaid diagram to SVG online, free and without signing up. Paste your code, preview it, and download a vector file that stays sharp at any size.
- Mermaid to PDF Convert Mermaid to PDF online, free. Paste your code and download a vector PDF with selectable text, sized to the diagram or to A4 or Letter. Runs in your browser.
- Mermaid to JPG Convert Mermaid to JPG online, free. Paste your code, choose the size and quality, and download a JPEG that any app, CMS or chat tool accepts.
- Mermaid to WebP Convert Mermaid to WebP online, free. Smaller than PNG, with transparency and sharp edges. Paste your code, set the size and download.
- Mermaid to draw.io Convert Mermaid to draw.io (diagrams.net) XML, free. Flowcharts become native, editable shapes and connectors; other diagrams arrive as an image.
- Mermaid to Excalidraw Convert Mermaid to Excalidraw, free. Flowcharts become editable, hand-drawn Excalidraw shapes and arrows. Download a .excalidraw file or paste onto the canvas.
Convert to Mermaid
Generate Mermaid from data you already have: schemas, specs, logs and spreadsheets.
- SQL to ER diagram Convert a SQL schema to a Mermaid ER diagram, free. Paste CREATE TABLE statements from Postgres, MySQL, SQLite or SQL Server and get tables, keys and relationships.
- JSON to Mermaid Convert JSON or YAML to a Mermaid mind map or flowchart, free. Paste a config file, API response or data structure and see its shape as a diagram.
- CSV to Mermaid Convert CSV to a Mermaid Gantt chart, pie chart or bar and line chart, free. Paste spreadsheet data, map the columns, and get a chart that lives in your docs as code.
- package.json dependency graph Turn a package.json into a Mermaid dependency graph, free. See dependencies, devDependencies and peerDependencies grouped, with their version ranges.
- Git log to Mermaid Convert git log output to a Mermaid gitGraph, free. Run one git command, paste the output and get your branches, merges and tags as a diagram.
- OpenAPI to sequence diagram Convert an OpenAPI or Swagger spec to a Mermaid sequence diagram, free. Pick the endpoints and get the calls, responses and error branches drawn out.
- AI Mermaid generator Pro AI Mermaid diagram generator: describe a process or system in plain words and get Mermaid code, checked by the Mermaid parser before you see it. Included with Pro.
Check and clean up
Find the exact line that breaks a diagram, and tidy code before you commit it.
- Mermaid validator Free Mermaid validator and syntax checker. Paste your diagram and get the exact line and column of any error, plus a plain-English hint at the usual causes.
- Mermaid formatter Free Mermaid formatter and beautifier. Re-indents subgraphs, loops and class blocks, spaces out arrows and tidies blank lines, without changing what the diagram means.
Design and share
Style diagrams, preview READMEs and put diagrams on other sites.
- Mermaid theme generator Mermaid theme generator: pick colours, see flowcharts, sequence diagrams and charts update live, and copy the themeVariables as front matter, an init directive or JSON.
- Markdown + Mermaid preview Preview Markdown with Mermaid diagrams the way GitHub renders it: tables, task lists, alerts and ```mermaid blocks, live in your browser before you push.
- Embed and badge generator Generate embed code for Mermaid diagrams: a GitHub README block with an "Open in TryMermaid" badge, a Notion embed link, an iframe and a web component.
Site utilities
Small helpers for the sites your diagrams live on.