# Default appearance in PDF viewers

Using pikepdf you can control the initial page layout and page mode, that is, how a PDF will appear by default when loaded in a PDF viewer.

These settings are changed written to the PDF’s Root object. Note that the PDF viewer may ignore them and user preferences may override, etc.

    from pikepdf import Pdf, Dictionary, Name
    with Pdf.open('input.pdf') as pdf:
        pdf.Root.PageLayout = Name.SinglePage
        pdf.Root.PageMode = Name.FullScreen
        pdf.save('output.pdf')

For reference, the tables below provide summarize the available options.

PageLayout definitions
Value | Meaning
--- | ---
Name.SinglePage | Display one page at a time (default)
Name.OneColumn | Display the pages in one column
Name.TwoColumnLeft | Display the pages in two columns, with odd-numbered pages on the left
Name.TwoColumnRight | Display the pages in two columns, with odd-numbered pages on the right
Name.TwoPageLeft | Display the pages two at a time, with odd-numbered pages on the left
Name.TwoPageRight | Display the pages two at a time, with odd-numbered pages on the right

PageMode definitions
Value | Meaning
--- | ---
Name.UseNone | Neither document outline nor thumbnail images visible (default)
Name.UseOutlines | Document outline visible
Name.UseThumbs | Thumbnail images visible
Name.FullScreen | Full-screen mode, with no menu bar, window controls, or any other window visible
Name.UseOC | Optional content group panel visible
Name.UseAttachments | Attachments panel visible