SharpMD: Markdown reader & editor

Read and edit Markdown in the browser: outline, folder tree, search, diagrams, math and in-place editing.

SharpMD opens Markdown files in the browser and lets you edit them on the formatted text. Set Chrome as the default app for .md files and a double-click opens them with an outline, the folder they live in and search. Click the extension icon and SharpMD opens in a tab, ready to start a note or open a file or a whole folder. READ • Outline built from the headings, with reading progress • Folder tree with the files next to the document • Search in the note and in every file at once • Math with KaTeX, diagrams with Mermaid and Graphviz, tables, footnotes, task lists, callouts, YAML front matter • Links to a section or to another file, picked from a list (Ctrl+K), and [[name]] links • Twelve themes, six light and six dark • Headings fold from the margin EDIT • Click a paragraph, a heading, a list item or a table cell and type • Type **bold** or `code` and the marks turn into formatting • Start a line with #, - or > to get a heading, a list or a quote • Right-click a block to insert, turn into, move, duplicate or delete • Select several blocks and move, copy, wrap or delete them in one step • Collapsible sections you insert, rename and wrap around other blocks • Kanban board: headings are columns and tasks are cards you drag, with due date, owner and your own attributes. In any other program it reads as a task list • Tables with a totals row and =sum, =avg, =min, =max • Diagram editor with live preview: templates, pieces to add with a button, color palettes, and errors explained with their line marked • Formula editor with live preview and buttons for fractions, sums and symbols • Find and replace, undo and redo for block operations • Type : to pick an emoji from a list • Focus mode and typewriter mode • Save with Ctrl+S, or turn on auto-save. If another program changed the file, SharpMD merges the two and asks when both touched the same lines FILES • The outline on top and your files below: the folder on disk, the notes kept in the browser and the cloud • Create from 30 templates, rename, move by dragging, delete • Paste an image and it is saved next to the document, smaller and without its metadata • Code and config files open highlighted, CSV opens as a table • PDFs, EPUB books, images, audio and video open inside SharpMD, next to your notes. A switch leaves only the Markdown files in the list • Export a note or a whole folder to a single HTML, PDF or Word file • Send a file or a folder from your disk to the cloud with a right click. It is a copy: the file on disk stays as it is • Copy the path of a file or a folder, or open it in your file manager TOOLS YOU TURN ON In Settings, under Tools. Each one is off until you turn it on. • AI assistant with your own key, from the provider you choose or a model running on your computer. It improves, shortens, translates or explains a selection, writes a table, a diagram or a summary, and answers questions about the open note. The result is a proposal you replace, insert, copy or discard • Dictation in English or Spanish, with spoken commands for punctuation, headings, lists and tasks • Read aloud with the voices of your device • Import to Markdown: a document, a spreadsheet, a presentation or a PDF becomes a note in the browser. From a PDF only the text comes out, with no OCR • JSON and YAML as a tree you fold and edit in place • Presentation mode, daily note, Word export and link map • Diagrams you explore: click a node to see what it connects to • Agents: your AI registers its agents through MCP and you watch them work in the sidebar • Community: templates, themes and diagram palettes shared by people, reviewed before they are published WEB APP AND EXTENSION • The extension button opens the web app at sharpmd.app, or the copy inside the extension when there is no connection • Both share the notes kept in the browser, the list of opened files and folders and the cloud session • A link can open a .md from your disk in the web app, after you confirm, when the file is in a folder you already opened with the extension CLOUD AND AI (OPTIONAL) • Sign in with a code sent to your email and send a note to the cloud with one click • Cloud notes open on any device, and without a connection once you have opened them • Share a note or a folder with another account, or make a read-only public link • Open a live session and edit a note with others by link, no account needed for them • Publish a cloud folder as a website with a menu, search and a theme • Connect Claude or any MCP client so your AI can read and write your cloud notes, with a token you can limit to one folder • Leave a comment on a block for your AI, and see its reply when it is done • An API, signed webhooks and inbound addresses for Slack, Make, n8n and Zapier • The cloud is encrypted, and folders with a password, end to end: their notes are encrypted in your browser and the server cannot read them • Free up to 10 cloud notes, with the MCP connection over them. The paid plan (USD 4 a month or USD 40 a year) has no limit and adds image uploads, sharing, live sessions, a published site, the API and automations, version history and the appearance options PRIVATE BY DESIGN Files are read in your browser and never uploaded. The extension sends no analytics and no usage counts. The web app at sharpmd.app counts a few anonymous events, with no cookie, no identifier and nothing about your notes, and you can turn that off in Settings. Cloud notes are optional: a note reaches the server only when you send it there. The AI assistant calls the provider you chose with your key, and SharpMD's server sees neither the key nor the text. Free and open source (MIT): https://github.com/SharpMD/sharpmd After installing, open the extension details and turn on "Allow access to file URLs" so it can open local files.