html-to-slack

n8n community node — converts HTML to Slack mrkdwn

Package Information

Released: 4 mo ago
Downloads: 21 weekly / 90 monthly
Latest Version: 0.2.2
Author: frerot

Available Nodes

HTML to Slack icon
HTML to Slack
Converts HTML to Slack mrkdwn formatted text

Documentation

n8n-nodes-html-to-slack

An n8n community node that converts raw HTML into Slack-compatible mrkdwn formatted text.

Install

In n8n (recommended)

Go to Settings → Community Nodes → Install and enter:

n8n-nodes-html-to-slack

Manual (custom nodes directory)

cd ~/.n8n/custom
pnpm install n8n-nodes-html-to-slack

Usage

Add the HTML to Slack node to your workflow. Connect any node that produces HTML (e.g. an HTTP Request, a webhook body, or a Gmail node) and map its HTML field to the HTML input.

[Webhook] → [HTML to Slack] → [Slack]

The node outputs all original fields plus a new field (default: text) containing the converted mrkdwn string, ready to pass directly to the Slack Send Message node.

Input / Output Example

Input HTML:

<p>Check out <a href="https://slack.com"><strong>Slack</strong></a> and visit https://n8n.io</p>

Output mrkdwn:

Check out <https://slack.com|*Slack*> and visit <https://n8n.io>

Full HTML → mrkdwn Mapping

HTML Slack mrkdwn
<b>, <strong> *text*
<i>, <em> _text_
<s>, <del>, <strike> ~text~
<code> (inline) `code`
<pre> ```\ncode\n```
<a href="U">T</a> <U|T> (named link)
<a href="U">U</a> <U> (text equals href)
<a href="mailto:x">T</a> <mailto:x|T>
Bare URL in text <URL> (post-processed)
<blockquote> > prefix on each line
<ul><li> • item
<ol><li> 1. item, 2. item …
<h1>–<h6> See headingStyle option
<table> See tableHandling option
<img> See imageHandling option
<br> \n
<p> content + \n\n
<hr> ───────────────
<div>, <span>, <section> … Tags stripped, inner text preserved
HTML entities (&amp;, &lt; …) Decoded before conversion

Slack mrkdwn Limitations

Slack's mrkdwn format is a subset of Markdown — several HTML features have no equivalent:

  • No headings — <h1>–<h6> are approximated as bold text
  • No tables — flattened to tab-separated plain text or stripped
  • No inline images — replaced with alt text, a link, or stripped
  • No underline — <u> content is preserved as plain text
  • No text colours — style attributes are ignored
  • All URLs must use angle-bracket syntax — bare URLs are not reliably auto-linked when posted via the API; this node wraps them automatically

Options Reference

Option Values Default Description
headingStyle bold | boldWithSeparator | strip bold bold → *text*; boldWithSeparator adds a ─── divider; strip removes headings entirely
tableHandling plainText | strip plainText plainText flattens cells tab-separated; strip removes the whole table
imageHandling altText | asLink | strip altText altText uses the alt attribute; asLink wraps src as <url>; strip removes the image
trimWhitespace true | false true Collapses 3+ consecutive newlines to a single blank line and trims the result

Development

# Clone and install
git clone https://github.com/<you>/n8n-nodes-html-to-slack.git
cd n8n-nodes-html-to-slack
pnpm install

# Unit tests (vitest, no n8n required)
pnpm test

# Hot-reload dev server (starts local n8n with this node loaded)
pnpm dev

# Type-check + build
pnpm run build

# Lint
pnpm run lint

File structure

nodes/HtmlToSlack/
├── HtmlToSlack.node.ts   — n8n integration layer
├── HtmlToSlack.node.json — codex / search metadata
├── htmlToMrkdwn.ts       — pure conversion logic (zero n8n deps)
├── htmlToMrkdwn.test.ts  — vitest unit tests
└── htmlToSlack.svg       — node icon

htmlToMrkdwn.ts has no n8n imports and can be used as a standalone library outside of n8n.

License

MIT

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