When it comes to working with PDFs, whether you’re a student annotating lecture notes, a professional reviewing contracts, or a team collaborating on reports, having the right PDF app can make all the difference. Reddit is one of the internet’s most active communities for crowd-sourced recommendations, and it’s a goldmine for discovering tried-and-tested tools used by actual people. Based on hundreds of Reddit threads, user reviews, and feedback across multiple subreddits like r/tech, r/productivity, r/ipad, r/Windows, and r/macapps, we’ve curated a list of the six best PDF apps trusted and loved by Reddit users for markup, comments, and collaboration.
TL;DR
Reddit users highly recommend a handful of PDF apps tailored for a variety of platforms and use cases. PDF Expert and Xodo stand out for their clean design and annotation features. Foxit PDF is a favorite for cross-platform compatibility. Tools like GoodNotes and Notability shine for handwritten markup on tablets, especially iPads, while PDF-XChange Editor is a powerhouse for Windows users looking for advanced features.
1. PDF Expert – iOS and macOS Favorite for Seamless Annotation
Best for: Apple users who want a simple yet powerful tool.
Why Reddit Loves It: One of the most praised PDF apps in subreddits like r/ipad and r/macapps, PDF Expert offers smooth performance, intuitive markup tools, and robust file management. Users highlight its polished interface and quick rendering, especially when dealing with large files.
Its annotation tools cover everything from highlighting and underlining to adding notes, shapes, and even embedded media. For collaboration, it allows real-time syncing through iCloud and integrates nicely with Apple Files and other services like Dropbox and Google Drive.
Notable Features:
- Fast performance and fluid annotation experience
- Searchable notes and hand-drawn markups
- Split view and tabbed interface for multitasking
- Support for applying digital signatures
2. Xodo PDF – Cross-Platform, Feature-Rich & Totally Free
Best for: Anyone seeking a free, full-featured PDF tool that works across devices.
Why Reddit Loves It: A consistent crowd favorite in r/Windows and r/Android, Xodo PDF stands out for its extensive annotation features, intuitive interface, and zero cost. Reddit users especially appreciate its real-time collaboration capabilities and seamless integration with cloud services.
Whether you’re adding a sticky note, using a stylus to highlight text, or syncing updates with a team, Xodo handles it smoothly. The browser-based version extends functionality across devices, making it ideal for students working both on desktop and tablets.
Notable Features:
- Real-time document collaboration and markup
- Available on Windows, Android, iOS, and web
- Free without watermarks or feature limitations
- Built-in file organizer and cloud sync
3. Foxit PDF – Lightweight, Powerful, and Multi-Platform
Best for: Professionals needing robust functionality across operating systems.
Why Reddit Loves It: Discussed widely on r/software and r/productivity, Foxit PDF Editor is lauded for its balance of speed and features. Unlike bloated alternatives like Adobe Acrobat, Foxit performs well even on modest hardware.
Redditors appreciate its markup capabilities—highlighting, drawing, annotating—as well as features suited for collaborative workflows such as shared reviews and cloud-based commenting. It supports Windows, macOS, Linux, and mobile platforms, making it ideal for large teams.
Notable Features:
- Full markup suite including stamps, typewriter, highlighting
- Built-in support for e-signatures
- Enterprise options for document workflow
- Secure editing with redaction support
4. PDF-XChange Editor – The Power User’s Choice on Windows
Best for: Windows users who need advanced PDF editing capabilities beyond simple annotation.
Why Reddit Loves It: Regularly recommended in r/Windows and even by users in r/legaladvice, PDF-XChange Editor is a powerhouse for users who want feature depth. Redditors love the precision tools, plugin architecture, and customization options it offers, especially in comparison to paid counterparts.
Its markup tools support layered comments, audio annotations, measurement tools, form creation, and more. Advanced users benefit from OCR (Optical Character Recognition), advanced scripting, and batch operations—all at a price point much lower than Adobe’s competing suite.
Notable Features:
- Comprehensive annotation and editing tools
- Custom stamps, callouts, and drawing abilities
- Extensive file format support and export options
- Free version available with minor limitations
5. GoodNotes – Handwritten Comments and Creative Annotation
Best for: Users who prefer handwritten notes or annotations, especially on iPads.
Why Reddit Loves It: GoodNotes consistently gets recommendations on r/ipad and r/ApplePencil threads. It transforms the way users mark up PDFs by enabling high-precision handwriting with Apple Pencil, organizing notes in notebooks, and allowing layered annotations.
Reddit users describe it as their “digital binder,” perfect for loading large academic PDFs and actively engaging with them through sketches, hand-drawn comments, and color-coded highlights. It offers PDF import and export, along with seamless cloud synching via iCloud or Dropbox.
Notable Features:
- Naturally written highlights, arrows, and comments
- Handwriting-to-text conversion supported
- Split-screen mode for multi-document note-taking
- Syncs via iCloud and supports PDF export
6. Notability – Real-Time Record & Annotate for Study and Meetings
Best for: Students and professionals who want to record audio while taking notes on PDFs.
Why Reddit Loves It: In r/gradschool and r/college, Notability comes up regularly among top picks for its ability to record lectures or meetings while simultaneously annotating PDFs in real time. This combination massively improves review efficiency as users can replay audio synced to their handwritten notes.
Redditors also enjoy the intuitive user interface, multi-color and multi-pen support, and ability to sort annotations into categories or ‘dividers,’ keeping documents organized and searchable.
Notable Features:
- Audio recording synced with annotation timeline
- Variety of pen types and colors for customization
- Automatic cloud backup and PDF export
- Import images, web clippings, and more
Conclusion: Choosing the Right PDF App Based on Your Workflow
While each of the six apps brings something unique to the table, the best one for you ultimately depends on your device ecosystem and workflow requirements. If you’re in the Apple ecosystem, PDF Expert, GoodNotes, and Notability are all excellent candidates. For cross-platform users or those on Android, Xodo and Foxit offer rich features without locking you into a specific ecosystem. Power users on Windows who need fine-grained annotation capabilities often swear by PDF-XChange Editor.
Reddit users have tested and vetted these tools in real-world conditions—be it studying for exams, revising contracts, or collaborating on projects. The consensus is clear: With the right PDF app, your productivity can significantly improve while reducing friction in your digital workflow.
Take advantage of free trials or free versions where available to test how each app fits your personal or team needs. In the end, the best app is the one that makes you feel equipped and efficient.
