CastReader — Text to Speech, Read Aloud + AI by CastReader

CastReader is a text-to-speech extension for reading webpages, PDFs and EPUB books aloud in Firefox. Natural voices, synchronized word and paragraph highlighting, and automatic scrolling help you follow long articles with your eyes and ears together.

Use AI Explain when a passage is difficult. It marks key ideas and explains them on the original page, so you can compare the explanation with the source as you read.

What you can do

• Webpages: read long articles, study materials and technical documentation on the original page.
• PDF and EPUB: open files in CastReader’s document reader and follow the text as it is spoken. EPUB files must be DRM-free and contain readable text.
• Reading controls: start at a chosen paragraph, adjust the speed, preview voices and save your favorites.

28 reading languages

Read in English and 27 other supported languages. The interface and reading tools support 28 languages; the text language is detected automatically and can be corrected. Choose the explanation language separately. Free and Pro voice choices vary by language.

Kindle Web compatibility depends on the book edition. Scanned documents require supported OCR and clear source images; OCR coverage differs from reading-language coverage.

Free and Pro

Start with 20 minutes of reading and 3 AI explanations per day for free. Pro offers more reading time and explanations, faster playback and additional voices. Cloned voices have separate usage allowances.

Privacy

Reading and explanations use online services to process the necessary content. Product usage and error statistics help improve the service. Privacy details: https://castreader.com/privacy-policy

Get started

1. Open a webpage or a compatible Kindle book.
2. Click CastReader or the headphone button.
3. For a PDF or EPUB, choose Read a file and select the document in CastReader’s reader.
4. Choose Read Aloud or Explain.
5. Listen while following the highlighted text.