Source panel

The "Source" tab in the panel shows the rendered and server-sent HTML source of the current page, and you can toggle between the two with the "Rendered" and "Server" buttons.

The HTML is syntax highlighted and sections are collapsible so you can quickly scroll through the source. By default full words are selected, but you can doubleclick to select entire lines for easy copying.

You can reload this view with the reload button in the panel.

Auto-formatting

Polypane automatically formats the HTML to fit the panel so even if you minify your HTML, it will be readable. The page is formatted with Prettier, and you can change the Prettier configuration.

If the source contains validation errors, Polypane is not able to format it.

HTML Validation

Polypane automatically validates both the server-sent and rendered HTML sources and lists anything it finds. Hover over the element or line info to scroll to and highlight the issue in the source, and highlight the element in the panes. Click the element to open it in the Elements panel.

For WCAG accessibility validation, see the Accessibility panel.

Errors are also indicated with markers in source itself.