GitHub HTML Preview Local

About

GitHub HTML Preview Local adds a Preview button to GitHub HTML file pages. Click it to instantly switch from the source code view to a rendered preview — no GitHub API token required.

■ Perfect for

· Quickly checking the appearance of an HTML file stored on GitHub
· Previewing small HTML files without setting up GitHub Pages
· Reviewing HTML files in private repositories without needing a personal access token
· Sharing and reviewing prototype HTML files directly in the browser

■ Key Features

· Adds a Preview button to GitHub HTML file pages
· Toggle between source code and rendered preview with one click
· No GitHub API access token needed
· Uses the source code already displayed in your browser — no extra network requests
· Automatically resolves relative CSS and image paths to GitHub raw file URLs
· Renders inside an extension-owned sandbox frame, avoiding GitHub's Content Security Policy restrictions
· Works with both public and private repositories (any repository you can already view in your browser)
· Available in English and Japanese

■ How to Use

1. Open an HTML file on GitHub
2. Click the Preview button added to the file toolbar
3. The source view switches to a rendered preview
4. Click Code to return to the source view

■ Privacy

· No requests are made to the GitHub API
· Your repository content is never sent to any external server
· The extension only targets GitHub pages needed to display the current HTML file

■ Limitations

· The preview uses source code already visible on the current page; files not shown on that page are not available
· Relative asset paths are resolved against GitHub raw URLs and require browser-accessible resources
· JavaScript execution is disabled in the preview sandbox for security
· Not intended as a replacement for a local development server or full GitHub Pages deployment
· GitHub UI changes may occasionally require extension updates