A reader clicks an inline footnote [1], jumps to the bottom of the page, reads, jumps back. Friction.

A sidenote sits in the margin next to the line it annotates

so the reader's eye never leaves the main text.

When to use which#

• Footnote: relatively standalone supplementary info — a citation, a caveat, a number. Readers can jump down; if they don't, they don't lose the thread.
• Sidenote: the aside you want them to see at the moment they read this sentence. Tufte's "annotation next to the figure" or the author's quiet muttering.

The biggest mistake is using sidenotes as footnotes — stuffing a paragraph of detail in the margin, then watching narrow-screen readers see an inline italic monster shoulder its way through your prose.

How#

Footnotes: [^1] + [^1]: text. Standard GFM.

Sidenotes: no markdown standard, write the HTML directly: <aside class="sidenote">text</aside>. rehype-raw lets the HTML through.

Comments

Comments are moderated. No email, no IP collection.