GitHub-Flavored Markdown is the main syntax that Trilium is following.

Images

When exporting, images are usually kept in the basic Markdown syntax but will use the HTML syntax if the image has a custom width. Figures are always embedded as HTML.

Tables

Simple tables are supported with the Markdown syntax. If the table is too complex or contains elements that would render as HTML, the table is also rendered as HTML.

Links

Standard Markdown links are supported.

Trilium internal links (that mirror a note's title and display its icon) are embedded as HTML in order to preserve the information on import.

Math equations

Both inline and display equations are supported, using the $ and $$syntaxes.

Admonitions

The Markdown syntax for admonitions as supported by Trilium is the one that GitHub uses, which is as follows:

> [!NOTE]
> This is a note.

> [!TIP]
> This is a tip.

> [!IMPORTANT]
> This is a very important information.

> [!CAUTION]
> This is a caution.

There are currently no plans of supporting alternative admonition syntaxes such as !!! note.

Wikilinks

Basic support for wikilinks has been added in v0.96.0:

• [[foo/bar]] will look for the bar.md file in the foo directory and turn it into an internal link.
• ![[foo/baz.png]] will look for the baz.pngfile in the foo directory and turn it into an image.

This feature is import-only, which means that it will turn wikilinks into Trilium-compatible syntax, but it will not export Trilium Notes into Markdown files with this syntax.