> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ederspark.com/llms.txt
> Use this file to discover all available pages before exploring further.
# PDF viewer & annotations (Focus)
> Read, highlight, and annotate research papers with Freiya's powerful PDF viewer and Focus mode featuring multi-color highlights and AI-powered Q&A
Freiya's PDF viewer, called **Focus mode**, provides a dedicated environment for deep reading and annotation of research papers. Highlight key passages, add comments, categorize your notes, and even ask AI questions about the paper, all in one seamless interface.
## Overview
Focus mode is designed for serious paper reading and analysis. It combines a full-featured PDF viewer with sophisticated highlighting tools and AI integration.
**Key features:**
* Multi-color highlighting system
* Comments and notes on highlights
* Category-based organization
* Export annotations to markdown
* AI Q\&A about the paper
* Vector search integration
* Saved reading sessions
Focus mode is available on all tiers, with advanced features on Pro and above.
## Accessing Focus mode
### Opening papers in Focus
1. Navigate to a paper in your library
2. Click **View PDF** or **Focus** button
3. PDF opens in Focus mode
This is the most common way to enter Focus mode.
1. Hover over a paper card
2. Click the PDF/Focus icon
3. Opens directly in Focus mode
Quick access without viewing paper details first.
1. Click **Focus** in the sidebar
2. View list of recent sessions
3. Click to resume where you left off
Pick up right where you stopped reading.
PDFs must be available (open access or uploaded) to use Focus mode. Papers without PDFs show a "PDF not available" message.
## PDF viewer controls
### Navigation
**Page controls:**
* **Next/Previous** - Arrow buttons or keyboard arrows
* **Page number** - Click to jump to specific page
* **Page thumbnails** - Sidebar with preview of all pages
**Zoom controls:**
* **Zoom in/out** - `+` and `-` buttons or keyboard
* **Fit to width** - Optimizes for screen width
* **Fit to height** - Optimizes for screen height
* **Custom zoom** - 25% to 400%
### View modes
**Best for:** Focused reading, highlighting, detailed study
Shows one page at a time with maximum space for content.
**Best for:** Skimming, browsing, finding sections
Pages flow vertically like a website. Scroll smoothly through the entire document.
**Best for:** Papers with two-column layouts
Shows facing pages side-by-side like a book.
### Display options
* **Full-screen mode** - Press `F` or `F11` for distraction-free reading
* **Rotate pages** - Rotate 90° for landscape papers
* **Dark mode** - PDF background adapts to your theme
* **Hide annotations** - Toggle highlight visibility with `H`
## Highlighting system
### Creating highlights
Click and drag to select text in the PDF
Highlight toolbar appears, select a color
Click comment icon to add notes
Highlight is saved automatically
### Highlight colors
Freiya provides six highlight colors, each suited for different purposes:
| Color | Suggested Use | Example |
| ---------- | ----------------------------- | ----------------------------------------- |
| **Yellow** | Key findings, main results | "Our method achieves 95% accuracy..." |
| **Green** | Methodology, approach | "We used a transformer architecture..." |
| **Blue** | Important quotes for citation | "As Smith et al. demonstrated..." |
| **Red** | Critical points, limitations | "However, this approach has drawbacks..." |
| **Purple** | Questions, future work | "Future research should investigate..." |
| **Orange** | Examples, case studies | "For instance, in the medical domain..." |
Develop a consistent color system and stick to it across all papers for easier review and export.
### Highlight categories
In addition to colors, you can assign categories to highlights for better organization:
**Predefined categories:**
* Methodology
* Results
* Discussion
* Introduction
* Limitations
* Future Work
* Key Concept
* Definition
* Citation
* Custom
### Editing highlights
Modify existing highlights anytime:
**To edit:**
1. Click the highlight in the PDF or sidebar
2. Edit comment text
3. Change color or category
4. Add or change emoji
5. Changes save automatically
**To delete:**
1. Click the highlight
2. Click delete button (trash icon)
3. Confirm deletion
Deleting highlights is permanent and cannot be undone.
## Comments and notes
### Adding comments
Every highlight can have an associated comment:
Highlight text as usual
Click the comment icon in the toolbar
Enter your thoughts, questions, or observations
Click outside or press save, comment is linked to highlight
**Comment features:**
* Plain text or basic formatting
* No length limit
* Edit anytime
* Searchable
* Export with highlights
### Emoji reactions
Quick emotional or categorical tagging with emojis:
**Common emoji uses:**
* 💡 Insight or idea
* ❓ Question or confusion
* ⭐ Very important
* 🔍 Need to investigate further
* ✅ Understood
* 🚨 Critical information
**To add emoji:**
1. Click highlight
2. Click emoji picker
3. Select emoji(s)
4. Multiple emojis supported
## Annotation sidebar
The sidebar provides a complete overview of all your annotations for the current paper.
### Sidebar features
**Main functions:**
* List all highlights chronologically
* Filter by color
* Filter by category
* Search annotations
* Jump to highlight in PDF
* Export options
### Filtering highlights
**Filter by color:**
* Click color buttons at top
* Shows only that color
* Multiple colors selectable
**Filter by category:**
* Dropdown menu
* Select one or more categories
* Combine with color filters
**Search annotations:**
* Search box at top of sidebar
* Searches highlighted text and comments
* Real-time filtering
### Sorting options
* **Page order** - From first to last page
* **Chronological** - Order highlights were created
* **Color** - Group by highlight color
* **Category** - Group by assigned category
## Focus sessions
Focus mode automatically saves your reading sessions.
### Session tracking
Each time you open a paper in Focus mode:
* New session created or existing resumed
* Reading position saved
* Scroll position remembered
* Zoom level preserved
* Last accessed timestamp updated
### Resuming sessions
Click **Focus** in the sidebar
See list of recent reading sessions
Click any session to pick up where you left off
Session data includes:
* Which paper
* Current page
* Zoom level
* Sidebar state
* Filter settings
## AI-powered Q\&A
Ask questions about the paper you're reading and get AI-powered answers with referenced sections.
### How it works
Click the AI chat icon in Focus mode
Type your question about the paper
AI responds with relevant passages cited
Click citations to jump to that section
### Question examples
**Good questions for Focus Q\&A:**
```
What methodology did the authors use for data collection?
Summarize the key findings in the Results section.
What are the main limitations mentioned in the paper?
How does this work compare to the Smith 2020 study?
What future research directions do the authors suggest?
```
Be specific in your questions. The AI has access to the full paper text and can provide precise answers.
### Vector search integration
Focus mode uses vector search to find relevant passages:
* Paper automatically indexed when opened
* Semantic search, not just keyword matching
* Finds conceptually related sections
* Understands context and meaning
**Database tracking:**
* Papers indexed in Focus mode
* Chunk count per paper
* Last indexed timestamp
* Quick re-indexing when needed
## Exporting annotations
Save your highlights and notes for use in writing and analysis.
### Export formats
**Best for:** Note-taking apps, writing drafts
```markdown theme={null}
# Highlights from "Paper Title"
## Page 3 - Yellow Highlight
> Highlighted text goes here...
**Comment:** My thoughts about this passage
**Category:** Methodology
**Date:** 2025-01-15
---
```
**Best for:** Spreadsheets, analysis
Columns: Page, Color, Category, Text, Comment, Date
**Best for:** Programmatic access, backups
Structured data with all highlight information.
**Best for:** Simple notes, email
Basic text format with highlights and comments.
### Export process
In Focus mode, ensure sidebar is visible
Find the **Export** button at top of sidebar
Select your preferred export format
Export all or filtered highlights
Save the file to your device
Export regularly to keep backups of your annotations, especially for important papers.
## Keyboard shortcuts
Master Focus mode with these shortcuts:
| Action | Shortcut |
| ---------------------- | ------------------------ |
| Next page | `→` or `Space` |
| Previous page | `←` or `Shift + Space` |
| First page | `Home` |
| Last page | `End` |
| Zoom in | `Ctrl/Cmd + +` |
| Zoom out | `Ctrl/Cmd + -` |
| Reset zoom | `Ctrl/Cmd + 0` |
| Full-screen | `F` or `F11` |
| Search in PDF | `Ctrl/Cmd + F` |
| Toggle highlights | `H` |
| New note | `N` |
| Highlight (last color) | `Ctrl/Cmd + H` |
| Delete highlight | `Delete` (when selected) |
[See all shortcuts →](/reference/keyboard-shortcuts)
## Advanced features
### Highlight toolbar options
**Additional features:**
* Copy highlighted text
* Google Scholar search for selected text
* Define selected word
* Translate selection
### Page annotations (coming soon)
Beyond text highlights:
* Draw shapes and arrows
* Add sticky notes anywhere
* Freehand drawing
* Annotation layers
### Collaborative annotations (coming soon)
Share and collaborate:
* Share annotated papers
* Comment threads on highlights
* Team reading and discussion
* Permission levels
### Multi-paper comparison (coming soon)
Read multiple papers side-by-side:
* Split-screen view
* Compare methodologies
* Cross-reference findings
* Synchronized scrolling
## Integration with other features
### With paper management
* Highlights visible in paper detail
* Annotation count shown in library
* Search papers by annotation content
* Filter by "has annotations"
[Learn about paper management →](/features/paper-management)
### With AI chat
* Start chat about paper from Focus
* AI has full paper context
* Reference specific highlights in chat
* Ask questions about annotated sections
[Learn about AI chat →](/features/ai-chat)
### With collections
* Filter collections by annotated papers
* Export collection annotations
* Compare annotations across papers
* Collection-level annotation stats
[Learn about collections →](/features/collections)
## Best practices
Use the same color scheme across all papers for consistency
Add comments to highlights, future you will thank you
Categorize highlights for easier filtering and export
Back up annotations periodically in case of data loss
### Effective highlighting
**Do:**
* Highlight complete thoughts or sentences
* Add comments explaining why it's important
* Use categories consistently
* Review and refine highlights
* Export for your writing
**Don't:**
* Highlight entire paragraphs (be selective)
* Highlight without reading carefully
* Use colors randomly
* Forget to add comments
* Leave highlights unorganized
## Troubleshooting
Check these issues:
* PDF URL may be broken or expired
* File may be too large
* Network connection problems
* Try re-adding the paper
Contact support if issue persists.
Possible causes:
* Network connection lost
* Browser storage full
* Account session expired
* Refresh page and try again
This happens with:
* Scanned PDFs (image-based, no text layer)
* Password-protected PDFs
* Corrupted PDF files
Solution: Try re-uploading or use a different PDF source.
Check if:
* Viewing the correct paper
* Highlights filter is active (showing none)
* Paper was re-uploaded (creates new version)
* Accidentally deleted
Contact support if highlights are truly lost.
Requirements:
* Paper must be indexed (automatic on first open)
* Need active internet connection
* Must have AI message credits remaining
* Wait a few seconds for indexing on first use
## Related features
Manage papers and access PDFs for Focus mode
Ask questions about papers with AI assistance
Integrate Focus mode into your reading workflow
Learn annotation strategies from experienced researchers