A Markdown footnote lets you add a numbered reference in the body text (like [^1]) and define its content elsewhere—usually at the bottom of the document (like [^1]: The note content). When rendered, the reference becomes a clickable superscript link, and the definition appears in a footnotes section. This tool automates the numbering and formatting so you don't have to track numbers manually.

Footnotes are supported in many extended Markdown flavors including Markdown Extra, Pandoc Markdown, R Markdown, MkDocs Material, and some static site generators like Jekyll (with plugins) and Hugo. GitHub Flavored Markdown (GFM) does not natively support footnotes—they are stripped from rendered README files. Always check your target platform's documentation.

In standard Markdown footnote syntax, continuation paragraphs must be indented by 4 spaces (or one tab). For example:
[^1]: First paragraph.
    Second paragraph, indented.
    Third paragraph, also indented.
This tool preserves line breaks in your footnote content and automatically indents continuation lines in the output.

Reference footnotes (the kind this tool generates) place a short marker [^1] in the text and the full definition elsewhere—keeping your prose clean and readable. Inline footnotes embed the note content directly at the reference point using syntax like ^[inline note text]. Inline notes are convenient for very short asides but can clutter the source text. This tool focuses on reference-style footnotes for better document structure.

Manual numbering becomes error‑prone when you add, remove, or reorder footnotes—you risk mismatched references or duplicate numbers. Auto‑numbering ensures your footnote markers always follow a clean sequence (1, 2, 3…) based on their order of appearance. The Renumber feature in this tool instantly reorders all your footnotes to match the flow of your document, saving you tedious manual updates.

GitHub Flavored Markdown does not render footnotes, so [^1] markers will appear as plain text in a GitHub README. However, you can still use this tool to prepare Markdown for platforms that do support footnotes (like Pandoc, MkDocs, or certain blogging engines), or to keep your source document well‑structured for future conversion. Always verify rendering on your target platform.