PDF Viewer

Omnilib's PDF Viewer lets you read, search, and annotate PDF documents. Whether you're reviewing research papers, reading documentation, or marking up contracts, the PDF Viewer provides all the tools you need.

Overview

The PDF Viewer offers:

• High-quality rendering — Crisp, clear PDF display
• Text selection — Select and copy text from PDFs
• Full-text search — Find text across all pages
• Annotations — Highlight, draw, and add notes, synced across collaborators
• OCR side panel — Extract text from scanned PDFs
• AI context — Smart truncation and vector search for long PDFs
• Multiple layouts — Single page, two-page, or continuous scroll
• Scroll position persistence — Returns to your last position when you reopen a file

Getting Started

Opening a PDF

Click any PDF file in the sidebar. The PDF opens in the main panel with a toolbar at the top.

Basic Navigation

• Scroll — Use the mouse wheel or scrollbar
• Pinch to zoom — Use the trackpad with two fingers (or a touch screen)
• Page navigation — Use the arrows or type a page number
• Zoom — Use the + and − buttons or keyboard shortcuts

Navigation

Page Controls

The toolbar shows your current position:

◀ Page 5 of 42 ▶

• Click the arrows to go forward or backward
• Click the page number to type a specific page
• Press Home for the first page, End for the last

Layout Modes

Switch modes using the layout button in the toolbar.

Zoom Controls

• Zoom In — + or = key
• Zoom Out — - key
• Reset — 0 key (returns to 100%)
• Pinch to zoom — Two-finger pinch on trackpad or touch screen

Scroll Position Persistence

When you reopen a PDF, the viewer returns to the last scroll position and zoom level automatically.

Search

Finding Text

1. Press Cmd+F (Windows: Ctrl+F).
2. Type your search term.
3. Press Enter to find matches.

Search highlights matches across all pages.

Search Options

Navigate matches with Enter (next) and Shift+Enter (previous). Close search with Escape.

OCR Side Panel

Desktop only. OCR uses the native desktop engine.

Click OCR in the viewer toolbar to open the OCR side panel. Use it to extract text from scanned PDFs and image-based documents.

The panel provides:

• Extract Text — Run OCR on the current PDF and display the extracted text page by page
• Figure extraction — Identify and extract figures and charts from the document

Extracted text is indexed in global search and available as AI context. See OCR for the full OCR workflow.

AI Context

When you add a PDF to AI context, Omnilib uses a smart truncation strategy to fit the content into the model's context window:

• The first 10 pages and last 3 pages are included as direct text.
• Pages in the middle are stored in a vector database and retrieved via RAG (retrieval-augmented generation) — the AI fetches the most relevant middle sections based on the question being asked.

This lets the AI work effectively with long papers and documents without losing key content at either end.

For scanned PDFs with no embedded text, OCR-extracted text is used automatically in place of the raw PDF stream.

Annotations

Highlight Tool

1. Click the highlight tool in the toolbar.
2. Select text in the PDF.
3. The text is highlighted with the current color.

To remove a highlight, click on it and press Delete.

Draw Tool

1. Click the draw tool.
2. Click and drag to draw freehand strokes.

Useful for circling items or drawing arrows.

Text Notes

1. Click the text tool.
2. Click where you want the note.
3. Type your content.
4. Click outside to save.

Double-click a note to edit it.

Rectangle Tool

Click the rectangle tool and drag to draw rectangular shapes. Useful for highlighting areas of diagrams.

Eraser Tool

Click the eraser, then click any annotation to delete it.

Color Picker

Click the color button in the toolbar and choose from 20 available colors. New annotations use the selected color.

Annotation Sync

Annotations sync across all collaborators in real time. If another user adds or removes an annotation, you see the change immediately without refreshing.

Keyboard Shortcuts

Navigation

Zoom

Search

Tips and Tricks

Reading Research Papers

1. Use two-page mode for academic papers.
2. Highlight key findings with different colors.
3. Add text notes with your thoughts.
4. Open the OCR panel to extract text for copying.

Quick Navigation

• Click the page number field to jump to any page.
• Use Home/End to quickly reach the start or end.
• Use search to find specific content.

Troubleshooting

PDF Not Rendering

• Wait a moment for it to load.
• Try zooming out if the page appears too large.
• Check whether the PDF file is corrupted.

Text Selection Not Working

Some PDFs contain only scanned images with no embedded text. Open the OCR panel to extract text from these documents.

Annotations Not Saving

• Ensure you have write access to the file.
• Check whether the file is read-only.

Search Not Finding Text

• Check your search options (case sensitive, etc.).
• The PDF may contain text as images. Use OCR to extract it.
• Try searching for partial words.

Related

• OCR
• LaTeX Editor
• Academic Paper Search
• Literature Review Generation