Markdown compatibility

Markdown started small, and every tool has added its own extras on top. The core syntax works the same almost everywhere. Beyond that, support varies. This table groups the features from the basics and advanced pages and shows where each one works.

✓ supported   ~ partial, or needs a plugin   ✕ not supported

Feature support

Feature CommonMark GitHub Obsidian VS Code Reddit Notion Slack Pandoc
Basic
Headings✓✓✓✓✓✓✕✓
Paragraphs✓✓✓✓✓✓✓✓
Lists✓✓✓✓✓✓~✓
Images✓✓✓✓✕✓✕✓
Code✓✓✓✓✓✓✓✓
Blockquotes✓✓✓✓✓✓✓✓
Horizontal rules✓✓✓✓✓✓✕✓
Bold✓✓✓✓✓✓~✓
Italic✓✓✓✓✓✓~✓
Strikethrough✕✓✓✓✓✓~✓
Advanced
Underline✓✓✓✓✕✕✕✓
Colour✓✕✓✓✕✕✕✓
Comments✓✓✓✓✕✕✕✓
Accordion✓✓✓✓✕~✕✓
Image sizing✓✓✓✓✕~✕✓
Extensions
Tables✕✓✓✓✕✓✕✓
Task lists✕✓✓✓✕✓✕~
Footnotes✕✓✓~✕✕✕✓
Math (LaTeX)✕✓✓~✕✓✕✓
Mermaid diagrams✕✓✓~✕✓✕✕
Autolink bare URLs~✓✓✓✓✓✓~
Heading IDs / anchors✕✓✓✓✕✕✕✓
Emoji shortcodes✕✓~~✕✓✓✕

Use this as a guide rather than a guarantee. Tools update often, and a feature may depend on a setting or plugin. When it matters, test in the tool you are writing for. For single HTML tags, see the HTML tag table.