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Review and edit markdown in browser.
Side by side with AI coding agent.

Markside lets you preview and edit local README.md, SKILL.md, AGENTS.md, plans, specs, or other markdown right in the browser. No extra app or window to switch back and forth.

Add to Chrome — it's free See how it works

zsh — claude

~/project $ claude

╭──────────────────────────────────────────╮

│ ✻ Welcome to Claude Code │

╰──────────────────────────────────────────╯

You: write a plan for adding auth

◆ Thinking…

◆ Writing docs/add-auth.md

✓ Created docs/add-auth.md (38 lines)

You: ▋

M README.md — Markside

file:///Users/eric/Code/task-api/docs/add-auth.md

Add Authentication

Implementation plan for JWT-based auth.

Tasks

✓ Set up Passport.js + JWT strategy

✓ Add POST /auth/login endpoint

○ Add JWT middleware to protected routes

○ Write integration tests

Architecture

→ POST /auth/login validates credentials, returns access + refresh tokens

→ Access token in Authorization header, refresh token in httpOnly cookie

→ authMiddleware.ts verifies JWT on protected routes

TypeScript ⧉

// middleware/auth.ts
const token = req.headers.authorization
if (!token) return res.sendStatus(401)
req.user = jwt.verify(token, SECRET)
next()

Notes

Use short-lived access tokens (15 min) + refresh tokens stored in httpOnly cookies. Rotate on each refresh.

Open any .md file. Markside takes it from there.

THE USUAL WORKAROUNDS

You've probably tried these.

✗

VS Code or other IDEs

Built for writing code, not reviewing plans. Opening one just to read a file drags you back into editor mode — exactly where you're trying not to be.

✗

Typora, Obsidian, etc.

Another app to install and manage. Switch windows back and forth breaking your AI coding flow.

✗

cat or bat

Read raw Markdown in the terminal. Not what you want.

✗

Glow

Renders Markdown in terminal. But terminal navigation is slow and high learning curve for most of us, and editing still means switching to vi.

✗

Grip

Renders Markdown in browser. But it spins up a local server and sends your file contents to the GitHub API. You may get rate limited and you will have to provide your GitHub credentials.

✓

Markside

Renders Markdown in browser via extension. Drag any .md file into your browser or ask the agent to open in browser. Markside renders content beautifully — review it, edit it, stay in your flow. Lightweight. No separate app or window to deal with. No spinning up local server, no outbound API call.

WHY MARKSIDE

Fast. Private. In flow.

Zero new windows

Your browser is already open. Drag the markdown file to browser and Markside renders it instantly — no new app, no context switch.

Edit without switching

Ctrl+E drops you into a full CodeMirror editor. Changes auto-save as you type. Stay in the browser, stay in flow.

Instant and lightweight

A lightweight browser extension with minimal overhead. Open a file and it renders instantly.

Your files stay local

Everything is read directly in Chrome. Nothing is uploaded, nothing is tracked. Your code never leaves your machine.

FEATURES

A seamless, beautiful Markdown experience.

SYNTAX HIGHLIGHTING

Beautiful code blocks for every major language. Copy button included.

MERMAID DIAGRAMS

Flowcharts, sequence diagrams, and Gantt charts render inline — no plugins needed.

DOCUMENT OUTLINE

A right-side panel auto-generates from your headings. Click any entry to jump to it.

FILE TREE

Open any local folder to browse your whole project. Reopens automatically on your next visit.

QUICK SWITCHER

Cmd+P fuzzy-searches to quickly find your file in the open folder.

EDITOR MODE

Ctrl+E switches to a full editor with syntax highlighting. Auto-saves as you type.

GET STARTED

Three steps. Thirty seconds.

Install the extension

Add Markside from the Chrome Web Store. Free, no account required.

Allow file access

In extension settings, enable "Allow access to file URLs." One toggle.

Open any .md file

Navigate to any file:// path in Chrome. Markside takes over automatically.

Review and edit markdown in browser.Side by side with AI coding agent.