⚙️ 100% In-Browser • Catalog • Layout • Zoom • Zero Recompression

Set PDF Viewer Preferences

Configure how PDF readers open your document: set initial page, default zoom (Fit Width / Fit Page), continuous or spread layout, fullscreen presentation mode, and navigation panels without modifying document contents.

Drop your PDF here, or browse files

Supports single and batch PDF configuration. 100% private in-browser processing.

⚡ Quick Presets:

Selected Documents

1 File

Document Details

File Name -

File Size -

Total Pages -

📄 Standard View

Page 1 of 1

Configuration Diff (Before vs After)

Setting	Original Setting	New Preference
Initial Page	Page 1	Page 1
Page Layout	Default	SinglePage
Page Mode	UseNone	UseNone
Initial Zoom	Default	fit-page

🛠️ Preference Controls

Open on Page: (1 – 1)

Initial Zoom Level:

Page Layout:

Navigation Pane / Page Mode:

Reading Direction:

🔒 Advanced UI & Window Flags ▼

Hide Toolbar

Hide Menubar

Hide Window Controls

Fit Window to Page

Center Window on Screen

Display Document Title

Print Scaling

Duplex Mode

How PDF Viewer Preferences Work

PDF Viewer Preferences are standardized metadata instructions embedded inside the PDF's Document Catalog (`/Root`). When compatible PDF readers like Adobe Acrobat, Apple Preview, Foxit, or browser viewers open the file, they parse these dictionary keys to automatically configure the initial window dimensions, zoom scale, navigation sidebars, and page spreads.

📑

PageMode & Layout

Controls whether bookmarks (`/UseOutlines`) or thumbnails (`/UseThumbs`) appear automatically upon opening, and sets single vs two-page spreads.

🎯

OpenAction & Zoom

Directs the reader to jump to a specific starting page and applies exact zoom scaling such as Fit Width (`/FitH`) or Fit Page (`/Fit`).

🛡️

100% Content Safe

Zero rasterization and zero image recompression. Modifies only the dictionary headers while leaving 100% of the document content intact.

Frequently Asked Questions About PDF Viewer Preferences

Does setting viewer preferences modify the text or images in my PDF? ▼

No. The tool only edits the PDF Catalog dictionary (`/PageMode`, `/PageLayout`, `/ViewerPreferences`, `/OpenAction`). All page content, fonts, vector graphics, and embedded images remain bit-for-bit identical.

Will all PDF readers honor these viewer preferences? ▼

Full-featured desktop PDF readers like Adobe Acrobat Reader, Foxit PDF, Apple Preview, and PDF-XChange support all standardized viewer preferences. Built-in web browser viewers (Chrome, Edge, Safari) honor initial page and zoom settings but may restrict full-screen or menu hiding for security reasons.

What is the difference between Fit Page and Fit Width zoom? ▼

Fit Page scales the document so that the entire height and width of a page fit within the viewer window. Fit Width scales the page so that its horizontal margins fill the screen width, which is ideal for comfortable continuous reading on laptops and desktop monitors.

How do I configure a PDF to open in Full Screen presentation mode? ▼

Select the Presentation quick preset or set Page Mode to Full Screen. When opened in Adobe Acrobat or compatible presentation readers, the PDF will immediately launch in full-screen slide mode.

Can I make a PDF open with the Bookmarks outline pane visible? ▼

Yes! Choose the Bookmarks preset or set Page Mode to Bookmarks / Outlines Panel Open (`/UseOutlines`). If the document contains bookmarks, the navigation sidebar will open automatically.

Does this tool support batch processing multiple PDF files? ▼

Yes. You can upload multiple PDFs at once, apply unified viewer preferences across the entire batch, and download all configured files individually or packaged inside a single ZIP archive.

What happens if my PDF is digitally signed? ▼

Our engine automatically detects existing digital signatures and displays a warning banner. Because cryptographic signatures seal the exact document byte stream, updating viewer preferences will invalidate the cryptographic hash.

Are my documents uploaded to any external server? ▼

No. IMGFixy processes your files 100% client-side inside your browser using WebAssembly. Your files are never transmitted across the internet, ensuring total confidentiality.

Can I set a specific starting page like page 15? ▼

Yes. Enter any valid page number in the Open on Page input. The engine constructs a valid `/OpenAction` destination pointer so the reader directly opens to that page.

How does the output validation work? ▼

Before enabling download, the engine programmatically reopens the newly generated PDF bytes in memory and parses the Catalog dictionary to verify that the requested keys were properly written and that no page counts or streams were corrupted.