Here are some workarounds and considerations to achieve your goal:
Workaround 1: Temporarily Public Image Link
- Upload Image: Upload the image you want to use as the banner to your document library.
- Copy Shareable Link: Get a shareable link to the image that allows 'anyone with the link' to view it.
- Update Banner: Paste this shareable link into the banner image URL field.
- Revoke Sharing: Once the banner is updated, revoke the public sharing link to maintain document security.
Workaround 2: Image Hosting Within SharePoint
- Site Assets/Images Library: Create a dedicated library (e.g., "Site Assets" or “Images”) within your SharePoint site.
- Upload Image: Upload your banner image to this library.
- Copy Image URL: Right-click the image and select 'Copy Image Address' or similar.
- Update Banner: Paste this image URL into the banner settings.
Limitations: These methods are workarounds and might have security or management considerations if you want to frequently change banners.
Addressing Your Ideal Solution
Sadly, there's no native way to make the home page banner work like the subpage title areas with a full-width image browser. Here's why, and some alternatives:
- Design Difference: SharePoint differentiates the home page banner for branding and navigation purposes.
- Customization: If you need the flexibility of the subpage title area, consider the following:
- Web Parts: Use a Hero web part or Image web part below the banner to create a visually similar section with more control.
- SharePoint Framework (SPFx): If you're comfortable with development, a custom SPFx web part could provide a tailored solution to suit your specific needs.