A rich text to Markdown converter takes text that already has formatting (copied from Google Docs, Word, Notion, Confluence, an email or a web page) and rewrites it as Markdown. Paste into the box on this page and the Markdown appears beside it as you paste or type.
Headings, bold, italic, strikethrough, links, bulleted and numbered lists, block quotes, code and tables come through. Google Docs is handled specially: it marks bold and italic with inline styles and wraps the whole paste in a bold tag, which naive converters turn into one giant bold block; this tool cleans that up first. The pasted HTML is sanitised, so scripts and tracking pixels don't run.
Limits: what arrives depends on what the source puts on the clipboard. Lists pasted from desktop Word sometimes arrive as plain paragraphs with bullet characters. Colours, fonts and layout have no Markdown equivalent and are dropped. Images become placeholder links.