Folio — Markdown Reader

A fast, local Markdown reader. Drop files, paste Markdown, read side by side, and view Mermaid diagrams.

Your Markdown, with a little more breathing room. Folio turns local Markdown files into a focused reading space. Open a document, follow an idea, and keep your notes close to the source. READ COMFORTABLY Enjoy clear typography, adjustable text size and reading width, and light or dark themes. Navigate with the document index and find passages with search. SEE MORE, SIDE BY SIDE Read up to four documents in one window. Each pane has its own scrolling, search, and heading navigation. Resize the panes to suit your work. KEEP NOTES IN CONTEXT Select a passage and attach a note. Highlighted source blocks and numbered note buttons stay visible when the Notes panel is closed. Click a button to return to its note. Save a Markdown copy with your notes and source references included. LET THE DETAILS COME THROUGH Read tables, task lists, syntax-colored code, and Mermaid diagrams. Copy code with one click. LOCAL BY DESIGN No account, analytics, or document uploads. Documents and notes are processed in your browser. Images linked to other websites load from those websites. GET STARTED Click Folio's extension icon, then open files, drag Markdown into the reader, or paste your source. To open local .md and .markdown file URLs directly, enable “Allow access to file URLs” in the extension's Details page. Save your notes before closing or refreshing. Notes and checkbox changes stay in the current tab; exported notes reopen as ordinary Markdown. Relative local images work only when the document is opened through its original file URL with file access enabled.