Rich text puts formatted content on the clipboard, so pasting into an email or a document gives you real headings, lists and links. Copy HTML puts the markup itself on the clipboard, which is what you want when pasting into a template, a CMS source view, or a code block.

Email clients delete style blocks and ignore external stylesheets. A heading that relies on a stylesheet arrives in Gmail looking like ordinary text. Inline styles put the formatting on each element, which is the only form that survives.

No. The converter is a few kilobytes of JavaScript running in this page. Drafts, meeting notes and internal documentation stay on your device.

No, and that is deliberate. Most converters pass raw HTML through. This output goes onto your clipboard and then into an email or a CMS, so passing a script tag through would turn the tool into a delivery mechanism. Raw tags are shown as text instead.

The common subset people actually type: ATX headings, emphasis, strikethrough, inline and fenced code, links, images, ordered and nested unordered lists, blockquotes, horizontal rules and pipe tables. Footnotes and definition lists are not supported.

Almost always because the formatting was carried by a stylesheet rather than by the elements themselves. Gmail, Outlook and most other mail clients strip style blocks and ignore external stylesheets entirely, so a heading that was styled by a rule arrives as ordinary text. Keeping inline styles switched on here puts the formatting on each element, which is the only form that survives the trip. If it still flattens, check that you used Paste rather than Paste as plain text — that shortcut discards formatting before the mail client ever sees it.

Very little. A hash and a space makes a heading, two asterisks around a word makes it bold, a dash and a space starts a bullet, and a number and a full stop starts a numbered list. Those four cover most of what people write in an email or a status update. Links are written as text in square brackets followed by the address in round brackets, and a table is rows of cells separated by pipe characters with a row of dashes under the header.

Yes. Rich text copy puts formatted content on the clipboard, and both Word and Google Docs read it as headings, lists, links and tables rather than as markup. Google Docs is slightly better at preserving nested list indentation than Word is; if a deeply nested list flattens in Word, one level of nesting usually survives where three does not.

Fenced code blocks and inline code come through as monospaced text with the spacing preserved, which is what you want when pasting a command into a message. They are not syntax-highlighted, because highlighting is done with a stylesheet and a stylesheet is the first thing an email client removes — coloured code would look correct in the preview here and arrive black.

Nowhere. The converter is a few kilobytes of JavaScript running inside this page, so meeting notes, internal documentation and half-written announcements stay on your device. Nothing is uploaded and nothing is saved — close the tab and the text is gone, so copy the result before you leave.

The smallest reasonable one is around 12 KB gzipped, which is 12 percent of this site’s entire JavaScript budget for a single tool. This converter is roughly 2 KB and covers what the tool is for.

Writing formatted content to the clipboard needs an API that some browsers and some private-browsing modes withhold. When that happens the tool falls back to plain text and tells you, rather than silently copying nothing.