---
title: "Does Slack support Mermaid? What works today"
slug: "does-slack-support-mermaid"
description: "Slack does not render Mermaid natively; it shows code. Here is what does work: Slack apps that render Mermaid, Canvases, and how to keep the diagram editable."
author: "Andrii"
published_at: "2026-09-24T00:00:00.000Z"
updated_at: "2026-09-24T00:00:00.000Z"
---

# Does Slack support Mermaid? What works today

> **Direct answer:** No. Slack has no built-in Mermaid renderer: Mermaid in a message, a snippet or a Canvas shows up as code. To see a diagram, use a Slack app that renders Mermaid. **Arialine** renders pasted Mermaid (via `/arialine`, an `@arialine` mention or a shared `.mmd` file) into a PNG and an interactive HTML file in the channel, and keeps the source so the team can edit it later.

## What Slack does with Mermaid today

- **Messages:** a ` ```mermaid ` block is formatted as code. Slack also escapes characters such as `>` and `&`, which breaks arrows like `-->>` if you copy the code back out.
- **Snippets and files:** a `.mmd` file is shown as text.
- **Canvases:** Markdown-style code blocks stay code; there is no Mermaid renderer.
- **Slack AI:** it can read the code but does not draw it.

## Ways to get a rendered Mermaid diagram into Slack

1. **Render elsewhere and upload an image.** Works, but the source and the image separate immediately.
2. **Use a renderer app** such as Mermaid Preview (`/mermaid` → PNG).
3. **Use Arialine**, which renders Mermaid and keeps it editable:
   - `/arialine` → paste Mermaid → **Create**,
   - `@arialine` + a Mermaid block,
   - share a `.mmd` file,
   - or put Mermaid blocks in a Markdown file and let Arialine turn it into a [Slack Canvas with rendered diagrams](/use-cases/markdown-to-slack-canvas).

Valid Mermaid is rendered as written, without an AI model. Arialine unescapes Slack's HTML entities first, so arrows survive.

## Why "rendered" is not enough

A picture answers "what does it look like now?". Teams also ask "what changed, who asked for it, and how do I change it again?". Arialine keeps the board's source and adds each addressed change in the thread as a version, with Undo and Rewind. Read [how to create and edit Mermaid diagrams in Slack](/blog/how-to-create-mermaid-diagrams-in-slack) for the full walkthrough.

## FAQ

### Will Slack add Mermaid support?

Slack has not announced native Mermaid rendering. Until it does, rendering comes from apps.

### Can I render Mermaid in a Slack Canvas?

Not natively. Arialine's Markdown-to-Canvas renders each Mermaid block as an embedded image in the Canvas.

### Can I create Mermaid without writing it?

Yes. Describe the diagram to `@arialine` in plain language and it writes the Mermaid for you.