To open local Markdown files by double-clicking them, you need to enable file access for the extension.
By default, Chrome extensions cannot access local files (file:// URLs) for security reasons. You need to explicitly grant this permission.
Navigate to chrome://extensions/ in your browser, or:
- Click the three-dot menu (⋮) in Chrome
- Go to More tools → Extensions
Scroll through your extensions or use the search box to find Markdown Viewer.
Click "Details" on the Markdown Viewer card.
Find the option "Allow access to file URLs" and toggle it ON.
✅ Done! You can now double-click .md files to open them in Chrome.
- Go to
about:addons - Find Markdown Viewer
- Click the extension
- Under Permissions, enable access to file URLs
- Right-click any
.mdfile - Select "Open with" → "Choose another app"
- Select Google Chrome
- Check "Always use this app to open .md files"
- Click OK
- Right-click any
.mdfile - Select "Get Info"
- Under "Open with", select Google Chrome
- Click "Change All..." to apply to all
.mdfiles
Depends on your desktop environment. Generally:
- Right-click the
.mdfile - Select "Properties" or "Open With"
- Choose Chrome/Chromium as the default application
- Verify the extension is enabled — Check
chrome://extensions/ - Confirm file access is on — The toggle should be blue/enabled
- Restart Chrome — Close all Chrome windows and reopen
- Check file association — Make sure
.mdopens with Chrome
Enabling file access means the extension can read local Markdown files. This is safe because:
- ✅ Markdown Viewer only processes Markdown content
- ✅ No data is sent to any server
- ✅ All processing happens locally
- ✅ The extension is open source and auditable
If you prefer not to enable file access, you can still use Markdown Viewer:
- Open Chrome
- Drag your
.mdfile into the browser window - The file will be rendered
- Press
Ctrl/Cmd + Oin Chrome - Navigate to your file
- Select and open it
View Markdown files on:
- GitHub
- GitLab
- Any website serving
.mdfiles
Now that file access is set up:
- Start using Markdown Viewer
- Explore the features
