html-to-markdown Johannes Kaufmann

Usage

💻 Golang library | 📦 CLI | ▶️ Hosted Demo | 🌐 Hosted REST API

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Golang Library

Installation

go get -u github.com/JohannesKaufmann/html-to-markdown/v2

Or if you want a specific commit add the suffix /v2@commithash

> [!NOTE]
> This is the documentation for the v2 library. For the old version switch to the "v1" branch.

Usage

package main

import (
	"fmt"
	"log"

	htmltomarkdown "github.com/JohannesKaufmann/html-to-markdown/v2"
)

func main() {
	input := `<strong>Bold Text</strong>`

	markdown, err := htmltomarkdown.ConvertString(input)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(markdown)
	// Output: **Bold Text**
}

• 🧑‍💻 Example code, basics

Use WithDomain to convert relative links to absolute links:

package main

import (
	"fmt"
	"log"

	htmltomarkdown "github.com/JohannesKaufmann/html-to-markdown/v2"
	"github.com/JohannesKaufmann/html-to-markdown/v2/converter"
)

func main() {
	input := `<img src="/assets/image.png" />`

	markdown, err := htmltomarkdown.ConvertString(
		input,
		converter.WithDomain("https://example.com"),
	)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(markdown)
	// Output: ![](https://example.com/assets/image.png)
}

The function htmltomarkdown.ConvertString() is a small wrapper around converter.NewConverter() and the base and commonmark plugins. If you want more control, use the following:

package main

import (
	"fmt"
	"log"

	"github.com/JohannesKaufmann/html-to-markdown/v2/converter"
	"github.com/JohannesKaufmann/html-to-markdown/v2/plugin/base"
	"github.com/JohannesKaufmann/html-to-markdown/v2/plugin/commonmark"
)

func main() {
	input := `<strong>Bold Text</strong>`

	conv := converter.NewConverter(
		converter.WithPlugins(
			base.NewBasePlugin(),
			commonmark.NewCommonmarkPlugin(
				commonmark.WithStrongDelimiter("__"),
				// ...additional configurations for the plugin
			),

			// ...additional plugins (e.g. table)
		),
	)

	markdown, err := conv.ConvertString(input)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Println(markdown)
	// Output: __Bold Text__
}

• 🧑‍💻 Example code, options

> [!NOTE]
> If you use NewConverter directly make sure to also register the commonmark and base plugin.

Collapse & Tag Type

You can specify how different HTML tags should be handled during conversion.

• Tag Types: When collapsing whitespace it is useful to know if a node is block or inline.
  • So if you have Web Components/Custom Elements remember to register the type using TagType or RendererFor.
  • Additionally, you can remove tags completely from the output.
• Pre-built Renderers: There are several pre-built renderers available. For example:
  • RenderAsHTML will render the node (including children) as HTML.
  • RenderAsHTMLWrapper will render the node as HTML and render the children as markdown.

> [!NOTE]
> By default, some tags are automatically removed (e.g. `