md2png

md2png – Markdown to Image (Go CLI & Library)

md2png renders Markdown into PNG, JPG, or GIF files using only Go. It ships as a CLI and as a library so you can call it from your own code. No Node, headless browsers, or helper scripts.

What it does

• Parses Markdown with goldmark and draws the result straight to an image buffer.
• Handles headings (H1–H5), paragraphs, ordered and unordered lists, bold text, code blocks, block quotes, tables, and horizontal rules.
• Dark and light themes, adjustable width, margin, and point size.
• Optional custom fonts: --font, --fontbold, --fontmono.
• Output format follows the -out extension.

Install

Clone and build:

git clone https://github.com/arran4/md2png.git
cd md2png
go build ./cmd/md2png

Dependencies are pure Go packages:

go get github.com/yuin/goldmark@v1.7.4 \
       github.com/golang/freetype@v0.0.0-20170609003504-e2365dfdc4a0 \
       golang.org/x/image@latest

Requires Go 1.22 or newer.

CLI usage

./md2png -in README.md -out out.png

Flags

Examples

Render Markdown from disk:

./md2png -in example.md -out example.png

Dark theme, wider frame, larger type:

./md2png -in blogpost.md -out post.png -theme dark -width 1400 -pt 18

Produce an animated GIF (palette handled for you):

./md2png -in slides.md -out slides.gif

Use your own fonts:

./md2png -in notes.md -out notes.jpg \
  -font /usr/share/fonts/TTF/DejaVuSans.ttf \
  -fontmono /usr/share/fonts/TTF/DejaVuSansMono.ttf

From stdin:

echo "# Hello\nThis came from stdin!" | ./md2png -out hello.png

Library usage

package main

import (
        "image/png"
        "os"

        "github.com/arran4/md2png"
)

func main() {
        img, err := md2png.Render([]byte("# Hello\nRendered inside Go!"), md2png.RenderOptions{})
        if err != nil {
                panic(err)
        }

        f, err := os.Create("hello.png")
        if err != nil {
                panic(err)
        }
        defer f.Close()

        if err := png.Encode(f, img); err != nil {
                panic(err)
        }
}

RenderOptions exposes the same knobs as the CLI. Set custom dimensions, swap themes, toggle link or image footnotes, or pass a font set created with md2png.LoadFonts.

Output

Light theme:

Dark theme:

How it works

1. Parse Markdown with yuin/goldmark.
2. Walk the AST and draw elements onto an RGBA image with freetype.
3. Wrap text, handle indentation, block quotes, code blocks, and tables.
4. Encode the result as PNG, JPEG, or GIF based on the -out extension.

Everything happens in memory; there is no HTML renderer or external process.

Roadmap

• Tables
• Inline images
• Syntax highlighting
• SVG output
• Configurable themes via YAML/JSON

License

md2png is available under the MIT License.