> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rapidreader.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Frequently Asked Questions

> Common questions and answers about Rapid Reader

Find answers to the most common questions about Rapid Reader. For technical issues, see [Troubleshooting](/troubleshooting).

<AccordionGroup>
  <Accordion title="What file formats does Rapid Reader support?">
    Rapid Reader supports **PDF**, **EPUB**, **Markdown**, and **plain text** files. You can also paste text directly, import articles by URL, subscribe to RSS feeds, or connect Raindrop.io for saved bookmarks.

    **Note:** PDFs must be text-based to work properly. Scanned documents or image-based PDFs cannot be read because they contain pictures of text rather than actual text data. If you cannot select and highlight text in your PDF, you will need to run it through an OCR tool first.
  </Accordion>

  <Accordion title="Is my data private?">
    Yes, your data stays private by default. Rapid Reader stores everything locally on your device — your library, reading progress, and preferences.

    If you upgrade to Pro and enable cloud sync, your data is encrypted and synced securely to our servers so it can follow you across devices. No data is shared with third parties.
  </Accordion>

  <Accordion title="Can I sync across devices?">
    Yes. **Pro users** get bidirectional cloud sync that keeps your reads, progress, library organization, and settings in sync across all your devices automatically. Changes sync in the background every 30 seconds.

    Free users store everything locally on each device. Each device maintains its own separate library and reading progress.
  </Accordion>

  <Accordion title="What is RSVP?">
    RSVP stands for **Rapid Serial Visual Presentation**. It is a speed reading technique that displays words one at a time in a fixed position, eliminating the eye movement required in traditional reading.

    Instead of your eyes scanning across lines of text, words come to you at a controlled pace. This removes physical overhead and allows faster reading with less fatigue.

    Learn more about the science behind it in [What is RSVP?](/learn/what-is-rsvp)
  </Accordion>

  <Accordion title="What is the red letter?">
    The red letter marks the **Optimal Recognition Point (ORP)** — the specific position in each word where your eye naturally focuses for fastest recognition.

    Words align around this fixed red letter, so your eye stays perfectly still while text streams past. The highlighting helps your brain instantly find the focal point without searching, reducing cognitive effort and enabling faster reading.

    See [Understanding ORP](/learn/understanding-orp) for a detailed explanation.
  </Accordion>

  <Accordion title="How fast can I read?">
    Most new users start comfortably at **250-300 WPM** (words per minute). With practice, many readers reach **500-700 WPM** for casual content, and some achieve **1000+ WPM** for lighter material.

    Your optimal speed depends on the content type. Dense technical material might need 200-300 WPM, while familiar topics can go much faster. Start slower and increase gradually as comprehension feels natural.

    See [Choosing Your Speed](/learn/choosing-your-speed) for guidance on finding the right pace.
  </Accordion>

  <Accordion title="What is the MCP server?">
    The MCP (Model Context Protocol) server lets AI tools like **Claude Desktop** send content directly to your Rapid Reader library. Generate an API key in Preferences, configure the server in your AI tool, and content flows to your cloud inbox automatically.

    This requires a Pro account with cloud sync. See [Integrations](/using/integrations) for setup instructions.
  </Accordion>

  <Accordion title="Is there a free trial?">
    The web app at [rapidreader.app](https://rsvp.rapidreader.app) is completely free to use — your reads are stored in your browser with no artificial limits. The Pro plan includes a 7-day free trial with full access to all features including cloud sync, unlimited cloud storage, and native apps.
  </Accordion>

  <Accordion title="How do I report bugs?">
    Email **[hello@rapidreader.app](mailto:hello@rapidreader.app)** with a detailed report. Please include:

    * **Platform:** Web, Mac, iOS, Android, Chrome, or Firefox
    * **Steps to reproduce:** What you did before the issue occurred
    * **Expected behavior:** What should have happened
    * **Actual behavior:** What happened instead

    Screenshots or screen recordings are helpful for visual issues. The more detail you provide, the faster we can investigate and fix the problem.
  </Accordion>
</AccordionGroup>

<Card title="Still have questions?" icon="life-ring" href="/support">
  Contact support if your question is not answered here
</Card>