svg2drawio

Convert SVG files into draw.io (mxGraph) XML from the command line.

The default output is a .drawio diagram in which every SVG element is a native draw.io cell: rectangles are rectangles, circles are ellipses, connectors are edges with draggable endpoints, text is a text cell with its own font settings. Arbitrary paths become inline stencils (shape=stencil(...)), which draw.io renders as first class shapes with editable fill and stroke.

Website: https://svg2drawio.runlocal.dev

Install

brew tap bcollard/svg2drawio
brew install --cask svg2drawio

Or with a Go toolchain:

go install github.com/bcollard/svg2drawio/cmd/svg2drawio@latest

Or from a clone:

make build     # ./bin/svg2drawio

Usage

svg2drawio [flags] <input.svg|directory>...

Command	Purpose
svg2drawio <input>...	Convert to .drawio — the default action
svg2drawio convert <input>...	The same thing, explicit (alias: diagram)
svg2drawio version	Version and build signature; --short for the number alone
svg2drawio skill install	Install the Agent Skill for AI coding tools
svg2drawio skill path	Where that skill is installed
svg2drawio completion <shell>	bash, zsh, fish or powershell completions
svg2drawio help [command]	Help for any command

Flags for convert:

Flag	Default	Meaning
-o, --out	next to the input	Output file or directory; - writes to stdout
--decimals	2	Rounding applied to coordinates; -1 keeps full precision
--scale	1	Multiplies every coordinate
--no-groups	off	Flattens SVG groups instead of keeping draw.io groups
--no-edges	off	Converts lines and polylines to shapes instead of edges
--name	file name	Name of the diagram page
-q, --quiet	off	Suppresses the per-file output line

Examples:

svg2drawio diagram.svg                        # writes diagram.drawio next to it
svg2drawio -o out/ icons/                     # converts a tree of SVGs
svg2drawio -o all.drawio a.svg b.svg c.svg    # one file, one page per SVG
svg2drawio -o - diagram.svg | pbcopy          # paste into Extras > Edit Diagram

An -o value with no file extension (or an existing directory, or a trailing /) is treated as a directory; anything else is a file.

Agent Skill

The repo-root SKILL.md is embedded in the binary, so AI coding tools can learn the CLI without a separate download:

svg2drawio skill install          # → ~/.claude/skills/svg2drawio/SKILL.md
svg2drawio skill install --print  # write it wherever you like

What is converted

SVG	draw.io
rect	native rectangle, rounded=1;absoluteArcSize=1;arcSize=<rx> when rx/ry are set
circle, ellipse	native ellipse
line, open polyline, straight open path	edge with floating endpoints and waypoints
polygon, curved or filled path	vertex with an inline stencil
text, tspan	text cell with font family, size, colour, weight, style and alignment
image	shape=image, data URIs rewritten the way draw.io stores them
g	draw.io group, with children rebased on the group origin
use, symbol	expanded before conversion
linearGradient, radialGradient	fillColor + gradientColor + gradientDirection
marker-start, marker-end	startArrow / endArrow block arrowheads
<style> rules, class, style=""	resolved through the CSS cascade before conversion
transform	baked into coordinates; rotations survive as rotation=, skews are baked into a stencil path
viewBox, width, height	page size and the user-unit scale

Opacity, stroke width, dash patterns, line caps and joins, display, visibility and style inheritance through groups are all carried over.

Not converted

• clipPath, mask, filter, pattern fills — the element is drawn unclipped and unfiltered; a pattern fill becomes no fill.
• fill-rule="evenodd" — mxGraph stencils have no fill rule.
• textPath, text on a curve — the text is placed at its anchor point.
• Animation elements are ignored.
• Text box sizes are estimated from the font metrics, since draw.io lays text out itself. Long labels may need a nudge after import.

How the inline stencils are encoded

draw.io reads shape=stencil(<data>) with Graph.decompress: base64 decode, raw inflate, decodeURIComponent. This tool writes exactly that — the stencil XML is URI encoded, deflated raw and base64 encoded — so the shapes are the same kind of object draw.io produces itself for custom shapes.

Development

make check     # gofmt, go vet, go test
make build     # ./bin/svg2drawio
make snapshot  # local goreleaser dry run

Package	Responsibility
internal/cli	cobra commands, file walking, output paths
internal/svgdom	SVG parsing, use/symbol expansion, transforms, colours, the CSS cascade
internal/svgpath	path data parsing, arcs to cubics, transforms, exact bounding boxes
internal/stencil	mxGraph stencil XML and the draw.io style encoding
internal/mxgraph	the .drawio file model
internal/convert	the SVG to draw.io mapping

website/ holds the static site published to svg2drawio.runlocal.dev; see website/README.md.

Releases

Tagging vX.Y.Z runs .github/workflows/release.yml: goreleaser builds macOS and Linux binaries (amd64 + arm64) stamped with version, commit and build date, attaches an SPDX SBOM and third-party licences, and pushes the Homebrew cask to bcollard/homebrew-svg2drawio.

License

MIT — see LICENSE.