Read with your eyes and ears
Get through the report, paper or chapter you keep putting off. CastReader reads your PDF aloud while you follow the highlighted passage. Start with a file in your browser, or bring it into the app on your computer, phone or tablet.
Free to start. See AI allowances and Pro options.
Research paper.pdf
PAPERS → PROGRESS
Import a PDF. Follow every passage.
A focused reading session
Choose a PDF in the online document reader, or import it into CastReader. A file with selectable text is the easiest starting point. Keep the original page available to check figures and reading order.
Preview an available voice and choose a comfortable speed. The web reader offers on-device voices without an account; sign in for CastReader AI voices and AI Explain.
Press Play and follow the highlighted text. Pause to examine a table, revisit a sentence or take notes. Use Read & Explain on a difficult passage when it is available in your reading workflow.
See the reading experience
CastReader brings speech, synchronized highlighting and scrolling together. When a passage needs more attention, pause and work through it.
Listen to the introduction and discussion while keeping the PDF in view. Stop at equations, figures and citations to inspect them yourself. Speech is most useful when it helps you stay with the argument, rather than skip the evidence.
Read in manageable sections and replay an unfamiliar explanation. Choose a voice that matches the document’s language. For a dense paragraph, AI Explain can help unpack the wording while you compare it with the source.
Follow the highlighted passage through a long report or proposal. Pause at headings and tables to decide what deserves closer attention. A slower first pass can be more useful than rushing through a document at maximum speed.
Choose where you read. Each route below explains where the document opens and how to start playback.
WEB · WINDOWS · CHROMEBOOK
Open a local PDF in CastReader’s web document reader. This is a direct route on Windows, Mac and Chromebook without installing a PDF application.
MAC APP
CastReader for Mac is available on the Mac App Store for macOS 14.6 or later. Use the app for repeated reading sessions with your local documents.
IPHONE & IPAD
Use the CastReader app to keep the document and reading controls together. A larger iPad screen leaves more room to follow the source.
ANDROID
Import a document into CastReader for a focused reading view on your phone or tablet.
Start with the reader that matches your file and the way you want to work.
Acrobat has its own Read Out Loud feature. Our Acrobat guide covers that route. If you want CastReader’s reading and explanation workflow, import the PDF into CastReader instead.
Use the CastReader web document reader. On-device voices are free and require no account; voice availability depends on your browser and operating system.
The apps support a library workflow for documents and books. You can use the same CastReader account for Pro entitlement across supported clients; file and progress synchronization depend on the workflow.
Text-based PDFs and scanned pages are different inputs. The current web reader offers Google OCR for scanned pages in Bengali, Marathi, Punjabi (Gurmukhi) and Tamil, after sign-in and explicit consent. For other scanned-page languages, prepare a text layer in another tool first. App OCR coverage can differ; check the recognized passage before reading.
Try a simpler export or a text-based copy from the publisher. Compare the reading view with the original page. Complex tables, formulas and multi-column layouts may need manual review.
The web PDF limit is 80 MB, and processing also depends on your device. The web reader has no password-entry or protection-removal workflow. Use a readable copy you are authorized to open.
Open CastReader’s document reader, choose a text-based PDF, check the extracted passage, choose a voice and press Play. On a phone or tablet, import the PDF into the CastReader app instead.
Yes. The web reader offers available on-device voices without an account. CastReader AI voices require sign-in and include daily Free allowances. Pro adds higher limits and additional voice access; see current plans.
Support depends on the client and language. The web reader currently offers Google OCR for Bengali, Marathi, Punjabi (Gurmukhi) and Tamil scanned pages after sign-in and consent. Other scanned-page languages need a text layer prepared elsewhere. Check OCR results before listening.
Yes. Import a PDF into the CastReader app on iPhone, iPad, Android phones or Android tablets, then start reading from the imported document. Use the mobile app guide for downloads.
The web reader parses the original PDF locally. Choosing a cloud AI voice sends text for speech generation, including upcoming buffered passages. AI Explain processes the requested content. Opting into supported cloud OCR sends page images for recognition. Native app storage and import workflows may differ.
The standard local web reader plays the document in place and does not export MP3 files. This workflow is designed to keep the source available for highlighting, navigation and checking figures.
A scan, missing text layer, unusual font encoding or complex page layout can affect extraction. Compare a short passage with the source and try a simpler export. See PDF read aloud troubleshooting.
Choose your reading route, try a passage and keep the original in view.
Updated October 21, 2026 · CastReader product team · Voice, extraction and highlighting support vary by client, language and source. CastReader is independent of Google, Microsoft, Adobe and Amazon. Their product names identify the reading sources discussed here.