Tired of uploading sensitive documents to the cloud? Discover LeedPDF, the free tool that lets you annotate PDFs directly in your browser—without your files ever leaving your device.
TL;DR

  1. Annotate PDFs for free in your browser, with no sign-ups or file uploads, ensuring complete privacy.
  2. Enjoy powerful drawing, search, and touch-screen features with top-tier performance and WCAG AAA accessibility compliance.
  3. Easily run it locally or integrate it into your projects, making it perfect for students, developers, and privacy advocates.

Prologue: The PDF Cloud Trap

1. The Great PDF Rip-off

Who should read: Anyone frustrated by the privacy terms and paywalls of modern PDF tools.
We’ve all been there. A critical contract, a sensitive research paper, or a medical report lands on your desk. You open an online PDF tool, and it cheerfully asks you to “create an account,” “upload your document,” and “upgrade to premium.” In that moment, your sensitive data is exposed, traveling across who-knows-how-many servers. And don’t get me started on the “freemium” models with crippled features. This business model of holding user data hostage is ripe for disruption.

  • Core Points:

    • The privacy risks and hidden costs of mainstream cloud-based PDF tools.
    • The growing user demand for data sovereignty.
    • The rise of open-source, local-first solutions as a powerful alternative.

2. Enter LeedPDF

Who should read: Anyone who wants a quick snapshot of this tool’s standout features.
And that’s where LeedPDF strides in, like a low-key tech superhero. It’s a modern, open-source PDF annotation tool that runs entirely within your browser. No servers, no accounts, no tracking. It transforms any PDF into an interactive canvas where you can draw, annotate, and collaborate freely, all while your file stays securely on your device. This isn’t just a technical win; it’s a profound statement of respect for user privacy.
LeedPDF Logo

  • Core Points:

    • LeedPDF’s core value: 100% client-side processing, completely free.
    • Tech stack highlights: Built on SvelteKit, TypeScript, and PDF.js for a modern, efficient experience.
    • Versatile use cases: From student note-taking to professional contract review.

Intuition: What Makes It Different

3. Privacy & Performance Powerhouse

Who should read: Decision-makers who prioritize data security and efficiency.
Why is LeedPDF so confident? The answer lies in its “privacy-first” design philosophy. All PDF rendering and annotation happen on your device, meaning your documents never touch a third-party server. This local processing not only provides ironclad security but also delivers blistering performance—no network latency, instant loading, and crisp rendering on high-DPI screens. It’s like packing a powerful PDF workstation right into your browser.

  • Core Points:

    • 100% client-side processing guarantees your data never leaves your device.
    • Local rendering delivers superior performance: instant loading and smooth zooming.
    • A world of difference in responsiveness compared to cloud-based tools.

4. Get Started in 5 Minutes

Who should read: New users who want to be up and running in minutes.
Don’t think a powerful tool has to be complicated. LeedPDF’s minimalist design will surprise you. Just visit leed.my, and the world is your oyster. Drag and drop a PDF file onto the page, or click the folder icon to select one. In a flash, the PDF loads. The top toolbar is intuitive: pencil, highlighter, text, shapes… it’s like a familiar physical stationery kit. No tutorials, no guides—your intuition is all you need to start annotating.
LeedPDF in action - annotating a Y Combinator fundraising guide with highlights, comments, and drawings

  • Core Points:

    • Visit leed.my to begin instantly, no installation needed.
    • The intuitive design of drag-and-drop uploading and the clear toolbar.
    • The seamless experience of your first drawing and text annotation.

Practical: From Annotation to Search

5. The Art of Basic Annotation

Who should read: Students and beginners looking to master core features.
Let’s get practical. Open a lecture slide, use the pencil tool to underline a key formula, then switch to the highlighter to mark an important paragraph. Need to add a note? Click the text tool and type directly in a blank space—font and color are adjustable. For a quick comment, slap on a yellow sticky note with “Review this section!” All actions support undo/redo (Ctrl+Z/Y), giving you the freedom of paper with the flexibility of digital.

  • Core Points:

    • Using the pencil, highlighter, text, and sticky note tools effectively.
    • Boosting efficiency with keyboard shortcuts (e.g., 1-9 to switch tools).
    • The peace of mind provided by the local auto-save feature.

6. Advanced Drawing & Collaboration

Who should read: Designers or users who need complex, precise annotations.
For more demanding scenarios, LeedPDF is equally capable. Use the rectangle tool to circle an anomaly in a chart, the arrow tool to point to a key node in a process, or even draw a star to mark the most critical conclusion. The coolest feature is the “smart eraser,” which precisely removes any element it intersects without affecting others. On an iPad, Apple Pencil pressure sensitivity makes line thickness vary with your hand pressure, an experience rivaling professional drawing software.

  • Core Points:

    • Practical applications for shape tools (rectangles, arrows, stars).
    • The logic behind the smart eraser’s precise deletion.
    • The optimized experience with styluses like the Apple Pencil.

7. The Ultimate PDF Search Engine

Who should read: Researchers who need to quickly find and discover documents.
This is LeedPDF’s “killer feature.” It integrates the Brave Search API, allowing you to search the entire internet for PDF files directly from within the app. Type in a keyword, and it intelligently filters and returns only PDF results, with pagination support. See a document you like? Click it, and it opens directly in LeedPDF, no tab-switching required. It’s like having a search engine built exclusively for PDFs, doubling your efficiency when looking for resources or literature. For setup details, check the project’s docs/SEARCH_FEATURE.md.

  • Core Points:

    • Using the Brave Search API for web-wide PDF discovery.
    • Smart filtering and pagination to enhance search efficiency.
    • Opening documents directly from search results into the LeedPDF interface.

8. A Seamless Mobile Experience

Who should read: Tablet and smartphone users who need to be productive on the go.
Who says professional tools are confined to desktops? LeedPDF’s mobile interface is meticulously optimized for smooth operation on phones. Pinch-to-zoom, single-finger panning—it all feels natural. On a tablet, it truly shines; paired with a stylus, you can comfortably review documents from your couch. Because all processing is local, your work isn’t interrupted even when you’re on a flight without internet.

  • Core Points:

    • Optimized touch gestures for the mobile experience.
    • The perfect combination of tablets and styluses for annotation.
    • Offline capability to maintain productivity anywhere, anytime.

Advanced: From User to Contributor

9. Running LeedPDF Locally

Who should read: Developers who want to customize or use the app offline.
Want to take more control? Run LeedPDF on your own local server. This not only allows for offline use but also sets the stage for custom development. The process is straightforward, assuming you have Node.js 18+ and pnpm installed.
Must-Have Minimal Runnable Example:
Open your terminal and enter the following commands:

# 1. Clone the project to your local machine
git clone https://github.com/rudi-q/leed_pdf_viewer.git
# 2. Navigate into the project directory
cd leed_pdf_viewer
# 3. Install all dependencies
pnpm install
# 4. Build the project and start the preview server
pnpm build && pnpm preview

Input: Execute the commands above, one by one, in your terminal.
Output: The terminal will display the build process and finally show a message like Local: http://localhost:4173/.
Expected Result: Opening http://localhost:4173 in your browser reveals an interface identical to the online version. You can upload a PDF and start using it, completely independent of an internet connection.

  • Core Points:

    • Prerequisites: Installing Node.js and pnpm.
    • The complete workflow: cloning, installing dependencies, building, and previewing.
    • Verifying that the local server is running correctly.
      Requires code example/commands: Yes

10. Exploring the Project & Contributing

Who should read: Aspiring contributors who want to improve the codebase.
Once it’s running, take a look under the hood. LeedPDF’s code structure is clean and follows SvelteKit best practices. src/lib/components/ holds all the Svelte components, src/lib/stores/ manages state, and the core logic for PDFs and drawing lives in src/lib/utils/. The project is pre-configured with ESLint and Prettier to ensure a consistent code style. If you want to contribute, simply Fork the repo, create a new branch, commit your changes, and open a Pull Request.

  • Core Points:

    • A breakdown of the core project directory structure.
    • Code style standards and development tooling configuration.
    • The standard open-source contribution workflow.
      Requires code example/commands: Yes

11. Building Your Desktop App

Who should read: Enterprise users or anyone needing a native experience.
While the web version is powerful, you might need a more native-like experience. LeedPDF offers a path to a desktop app using the powerful Tauri framework. Tauri lets you build lightweight, secure desktop apps with web technologies. First, you’ll need a Rust environment. Then, with a few commands, you can package your very own LeedPDF desktop application.

# 1. Install Rust (if you don't have it already)
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
# 2. From the project root, build the desktop app
pnpm tauri build

After the build completes, you’ll find the installer in the src-tauri/target/release/bundle/ directory. This is a huge plus for users who need offline deployment or integration into specific workflows.

  • Core Points:

    • The advantages of the Tauri framework: lightweight, secure, and cross-platform.
    • Steps to install the Rust environment and build the desktop app.
    • The additional benefits of the desktop version over the web version (e.g., better system integration).
      Requires code example/commands: Yes

Conclusion: Embracing an Open & Private Future

12. The Big Picture: More Than a Tool

Who should read: All readers, for a recap of the core value proposition.
LeedPDF is more than just a PDF annotation tool; it’s a statement. It proves that we can have powerful, feature-rich software without sacrificing our privacy or freedom. It elegantly wraps complex technologies like PDF.js and SvelteKit into an incredibly simple interface, which is the hallmark of great engineering.

  • Core Points:

    • The perfect balance LeedPDF strikes between privacy, cost, and functionality.
    • The vibrant open-source community and its continuous lifecycle of improvement.
    • The future trend of the “local-first” software design philosophy it represents.

13. Community: Join the Journey

Who should read: Enthusiastic users who want to give feedback or contribute.
A great project thrives on a great community. LeedPDF’s GitHub discussions are very active. Whether you want to share your experience (Wall of Love), ask for help (Q&A), or suggest new features (Ideas), you’re welcome. If the project has helped you, you can also support the developers through GitHub Sponsors to keep the goodness going.

  • Core Points:

    • How to participate in GitHub discussions to contribute to the project.
    • Ways to support the project’s sustainability through sponsorship.
    • The value of a community-driven project ecosystem for its users.

14. Looking Ahead: The Infinite Canvas

Who should read: Long-term users interested in the project’s future.
LeedPDF’s “infinite canvas” refers not just to its panning and zooming capabilities, but also to its limitless potential. In the future, we might see more powerful collaboration features, richer annotation types, and even support for other document formats. A Mac desktop app is also on the roadmap. More importantly, it serves as a blueprint for all developers on how to build a modern web application that is both respectful of user privacy and incredibly powerful.

  • Core Points:

    • LeedPDF’s future roadmap (e.g., Mac version, enhanced collaboration).
    • Its potential impact as a technical blueprint for the industry.
    • The central role of the open-source spirit in driving technological progress.

Chart & Diagram Suggestions

  1. Table: LeedPDF vs. Mainstream PDF Tools

    Feature LeedPDF (Web) Adobe Acrobat Foxit PDF Reader Smallpdf
    Privacy 100% Local Cloud Sync Cloud Sync Cloud Processing
    Price Free Subscription Free+Paid Free+Paid
    Open Source ✅ Yes ❌ No ❌ No ❌ No
    Platform Any Browser Desktop/Mobile Desktop/Mobile Web
    Accessibility WCAG AAA WCAG AA Unknown Unknown
    Key Conclusion: LeedPDF has overwhelming advantages in privacy, cost, and openness, with the highest accessibility standard.
  2. Mermaid Flowchart: PDF Search & Annotation Workflow

    graph TD
    A[User Enters Keyword] --> B{Brave Search API};
    B --> C[Returns PDF Results List];
    C --> D[User Selects PDF];
    D --> E[LeedPDF Loads Locally];
    E --> F[User Begins Annotating];
    F --> G[Auto-saves to Local Storage];

    Key Conclusion: The entire process from discovery to creation is a self-contained, efficient, and private loop.

  3. Performance Graph: LeedPDF vs. Cloud Tool Loading Times
    (Conceptual Diagram)

    • X-axis: PDF File Size
    • Y-axis: Loading Time
    • LeedPDF’s curve rises gently, while cloud tools’ curves are steep.
      Key Conclusion: As file size increases, LeedPDF’s local loading advantage becomes more pronounced, remaining largely unaffected by network conditions.
  4. Schematic: LeedPDF Tech Architecture
    (Conceptual Diagram)

    • User Interface
    • SvelteKit (App Framework)
    • PDF.js (PDF Rendering Engine)
    • HTML5 Canvas (Drawing Engine)
    • Browser
      Key Conclusion: Illustrates how LeedPDF leverages the modern web stack to implement complex functionality entirely within the browser.
  5. Feature Matrix: Mobile vs. Desktop
    (Matrix Diagram)

    • Rows: Features (Drawing, Search, Text, Shapes…)
    • Columns: Web, Desktop, Mobile
    • Mark with ✅ and ❌ for support.
      Key Conclusion: Core functionality is consistent across all platforms, with the desktop version offering slight advantages in performance and integration.

Frequently Asked Questions (FAQ)

Q: Is LeedPDF really completely free? Are there any hidden costs?
A: Yes, the web version is 100% free under the AGPL-3.0 open-source license, with no hidden fees or feature limitations. The desktop app and commercial licenses are paid options for those who need a native experience or commercial integration.
Q: Does my PDF data really never leave my computer?
A: Absolutely. All processing in LeedPDF, including PDF rendering, drawing, and saving, happens within your browser. It does not send your file content to any server. You can even disconnect from the internet after loading and continue working.
Q: Can I use LeedPDF without an internet connection?
A: Yes. Once you’ve visited and loaded the LeedPDF webpage for the first time, it’s cached in your browser. After that, you can open it and load previously opened PDFs or new local PDFs for annotation, even while offline.
Q: Can I use LeedPDF in my commercial project?
A: It depends on your use case. If your project is also open-source (under AGPL-3.0), then yes. If you want to integrate LeedPDF into a closed-source commercial product, you’ll need to purchase a commercial license. See the project’s Licensing section for details.

SEO Elements

  • Meta Title: LeedPDF: Free, Open-Source PDF Annotation Tool for Privacy
  • Meta Description: Annotate PDFs for free in your browser with LeedPDF. 100% private, no uploads required. Draw, search, and collaborate with this open-source tool.
  • Target Keywords: PDF annotation tool, LeedPDF, free PDF editor, PDF annotation tool, 隐私优先

Engineering Checklist

- [ ] Environment Check: Confirm Node.js 18+ and pnpm are installed.
- [ ] Code Retrieval: Successfully `git clone` the project repository.
- [ ] Dependency Installation: Run `pnpm install` without errors.
- [ ] Local Build: The `pnpm build` command executes successfully.
- [ ] Preview Test: Access `http://localhost:4173` and see the interface, and upload a PDF.
- [ ] Feature Verification: Test core functions like drawing, text, and saving.
- [ ] Mobile Test: Test touch controls in Chrome DevTools' mobile device view.
- [ ] Privacy Verification: Use the browser's Network tab to confirm no PDF file upload requests are made.

Questions & Exercises

  1. Food for Thought: LeedPDF uses the AGPL-3.0 license for its web version. Why do you think this “strong copyleft” license, typically intended for network services, is still an appropriate choice for a “client-side” tool? What does it mean for users and the community, respectively?
  2. Hands-on Exercise: Try running LeedPDF locally and add a new drawing tool to it, for example, a “wavy line” tool. You’ll need to modify components in src/lib/components/ and add a new tool button. Once you’re done, try submitting a Pull Request to the official repository.

Built with ❤️ for the open web
Privacy-focused • Lightweight • No tracking • No accounts • No servers