CLAUDE.md Viewer and Editor

Why AI instruction files deserve a real viewer

Coding assistants are steered by Markdown. A CLAUDE.md tells Claude Code how your project builds and what to avoid; an AGENTS.md does the same job for other coding agents; a SKILL.md packages a reusable skill; GEMINI.md, plan documents and design notes follow the same pattern. They are written as text, but they are full of structure: nested lists of rules, command tables, fenced shell snippets, warnings, links to other files. Read as raw text they are tiring, and a stray asterisk or an unclosed code fence can quietly change how a document is understood.

Open one here and you see what the author meant: headings you can navigate from the outline, rule lists with proper indentation, tables with aligned columns, commands in code blocks you can copy with one click, and > [!WARNING] callouts that stand out. It is a quick way to review an instruction file before you commit it, or to read a long plan an agent wrote for you before you approve it.

Open and read AGENTS.md, SKILL.md and plan files

• From your disk: use Open → Open file… or drag the file onto the page. Project instruction files usually sit at the repository root; skills live in folders you can browse to with the file dialog (show hidden folders if the path starts with a dot).
• From a repository: paste the GitHub link to the file into Open → From URL…. Anything public with a Markdown file behind it works, up to 2 MB.
• From a terminal or chat: copy the agent's answer and paste it into the editor. Tables, code and diagrams render instantly, and you can export the result as HTML or PDF.

For a SKILL.md, the YAML front matter between the two --- lines is displayed as a separate block above the body, so the name and description are easy to check. The viewer does not validate a skill — it shows you the text, rendered.

Diagrams, tables and callouts, rendered

Agents like to explain architecture with Mermaid diagrams: a fenced mermaid block becomes a flowchart, sequence diagram, class diagram, state machine or Gantt chart right in the preview (the Mermaid live editor page lists the diagram types). Tables of options or endpoints render as real tables, task lists show checkboxes, math between dollar signs is typeset with KaTeX, and code blocks are highlighted for 50+ languages with the language named in the header. Inline HTML is sanitized before it reaches the page, so a document you did not write cannot run scripts here.

Edit with live preview, then save it back

Switch to the Split layout to tidy an instruction file with the rendered result next to the source. The editor has a formatting toolbar, shortcuts, automatic list continuation and Tab indentation, and the preview scrolls in step with the line you are editing — useful for long files where a single mis-indented bullet changes the meaning. When you are done, Export → Download .md gives you the file to drop back into your project folder, and Copy Markdown puts the text on your clipboard. Sixteen light and dark themes, including a Claude theme with serif headings, let you choose a reading style that suits long documents.

New to the syntax? The Markdown cheat sheet covers it on one page, and the MD file guide explains how to open any .md file on Windows, Mac or phone.

Your project instructions stay private

Instruction and plan files often name internal tools, paths and conventions. Markdown Viewer renders everything with JavaScript in your browser and stores the document in local storage on your device; there is no account and no server-side copy. Opening a link is the only action that involves our server, and that fetch is not stored or logged. See the privacy page for details, or open the main Markdown viewer to start reading.