First check that you're on readnow.kobo.com (not the Kobo store page or library landing). The reader needs an actual book open. If you're inside a book and still nothing happens, check that the book has finished loading — Kobo lazy-loads the iframe srcdoc content. Wait until you can scroll through the page with text, then click again.
The auto-pager kicks in only when the currently-highlighted paragraph's last fragment is about to leave the viewport. If you're using a very short Kobo book or just opened to the title page, there may not be enough content to trigger pagination. Open a chapter with full body text and the pager will flip pages forward as needed.
CastReader picks the first paragraph that's at least 50% visible in your current viewport. If you opened to a place where two paragraphs are partially visible, it picks the one with higher coverage. Scroll until the paragraph you want is fully visible, then click CastReader again — it will start there.
This was a bug we fixed in CastReader 1.0.5+. Make sure you're on the latest version — the fix uses every fragment's client rect (not the union bounding box) when checking visibility. If you're still seeing it, please report the book title and chapter.
No. The Kobo desktop app uses an embedded WebKit / Chromium webview that browser extensions cannot inject into. The fix: open the same book on readnow.kobo.com in Chrome, Edge, or Firefox — your library and reading position sync automatically.
Yes. CastReader for Firefox handles Kobo's iframe layout the same way as Chrome. Install from Firefox Add-ons. (Note: some main-world content scripts that work in Chrome via world:'MAIN' are injected via <script> tag in Firefox; functionally identical.)
Most often this means Kobo's iframe content for later chapters hadn't fully loaded when you started. CastReader handles this by extracting paragraphs progressively across the visible iframe slice — but if Kobo deletes earlier iframes to save memory while you're reading, the audio stream may end. Refresh the page and start fresh from the page you stopped at.
Yes — CastReader auto-detects the book's language from the EPUB metadata's <html lang> attribute. It supports natural AI voices in 40+ languages including French, German, Italian, Spanish, Portuguese, Dutch, Polish, Czech, Japanese, Mandarin Chinese, and Korean.
No — it's a third-party browser extension developed independently. It does not log into your Kobo account, modify your library, or send data to Kobo. It only reads the rendered text inside the iframe (the same text your eyes see) and uses your speakers to play audio. It cannot break, suspend, or affect your Kobo account in any way.
Yes. CastReader's Send-to-Phone feature streams the audio from your desktop browser to a private Telegram bot. The desktop continues to flip pages automatically while you listen on your phone — no Kobo Plus Listen subscription needed.
Download the CastReader app to listen to your uploaded documents anywhere.
Hard numbers — not vibes — from authoritative sources
$2.22 billion
US audiobook sales in 2024, up 13% year-over-year (Publishers Weekly / Audio Publishers Association)
Source →51%
of US adults have listened to an audiobook in 2025 — roughly 134 million people (APA Consumer Survey 2025)
Source →2.2 billion
people globally with near- or far-vision impairment (WHO Fact Sheet, 2024). TTS is the primary access path for digital reading content.
Source →78%
of audiobook listeners multitask while listening — commute, chores, exercise (Audiolibrix Great Audiobook Survey, 2024)
Source →27.2 minutes
average single-trip US commute in 2024, up from 26.8 (US Census ACS via Statista). That's nearly an hour each day of audio-only time.
Source →effect size 0.35
measured comprehension lift from TTS for reading-disabled students across 22 studies (Wood, Moxley, Tighe & Wagner, Journal of Learning Disabilities, 2018)
Source →15.5 million
US adults with ADHD per CDC 2024 — about half diagnosed in adulthood (CDC MMWR, October 2024)
Source →Every Chrome Web Store review below is verifiable at the link in each card. We don't hide negative feedback — we answer it within 24 hours.
“This is 1 of the best TTS and its smooth. If this is truly free i'll keep this 100%. Every other TTS says its free but has a secret. They interrupt or they just say better ai voices pay. But i like this voice. I've tried loads and this is 1 of the best ones that actually says free.”
“Works perfectly on vivaldi. One suggestion though. I wish it had a play button appear next to a paragraph when we hover over it. Just like in the case of speechify.”
“Extremely user friendly short keys. Placed forward backward and speed up down as Natural as it could be. Voices are great and smooth. I would recommend it over many hyped products.”
“At the very least it's better than many paid TTS models. Still not as good as ElevenReader or LAP, but maybe the best free model for TTS.”
“So glad I can finally switch voices! The default was fine but I found one I actually enjoy listening to for hours. Small thing, huge difference.”
“Best one i found, user friendly, and great voice over.”
“ChatGPT's long answers are finally listenable. Let it generate while I listen — doubles my productivity. Love the inline button next to each response.”
“I tried using this add-on to listen to an ebook on the O'Reilly learning platform, and it works smoothly. However, it always restarts from the first paragraph whenever I scroll or select a different paragraph. Please consider adding a bookmark or checkpoint feature so users can mark where the reading should begin.”
↪ Founder reply
Replied by CastReader founder Yan Xu within 48 hours: acknowledged the issue, shipped a bookmark feature in the following release. Reviewer's verbatim feedback drove the v1.2 roadmap.
“Need to highlight text and select it.”
“Hard to select text.”
↪ Founder reply
Replied by CastReader founder Yan Xu within 24 hours: apologized, asked which site/browser the issue occurred on, provided a workaround using the keyboard shortcut, and offered direct support at support@castreader.ai.
We re-test, re-write, and ship continuously. Every entry has a real date.
Rewrote landing pages with verbatim Chrome Web Store testimonials, real audiobook market data, and tested-12-extensions methodology. Every claim now has a sourceable link.
Telegram audio streaming now auto-turns pages reliably across Kindle Cloud Reader and Apple Books. Reduces session interruptions by ~70% in internal testing.
Wrote up the OCR pipeline: how CastReader handles Amazon's 184 random font alphabets and 361 unique glyphs per Kindle book. Shared in dev.to.
Native macOS app reads Kindle for Mac with word-level highlighting. Floating player + system-wide hotkeys. No browser needed.
Ranked #10 in Daily, 99 upvotes, 4 community comments shaped the v1.2 roadmap.
Switched from older TTS engines to Kokoro neural voices. User reviews shifted from 'usable but robotic' to 'enjoy listening for hours' (verbatim from review by patrick chiang).
OCR success rate improved from 78% to 89% on English-language Kindle books. Multi-column page detection added for academic PDFs.
I built CastReader because I owned hundreds of Kindle books and couldn't listen to them on my morning runs without buying separate Audible copies. The technical problem — Amazon's Cloud Reader font encryption — turned out to be solvable with OCR. The product problem — making it actually pleasant across phones, desktops, and 40+ languages — took two years of iteration. We're a small team. I answer every Chrome Web Store review personally (see testimonials above — including the 3-star and 1-star ones). If something's broken or missing, email support@castreader.ai.
— Yan Xu, founder
Last reviewed: · CastReader Team — reviewed against 2025 testing data
Install once. Open any Kobo book. Press play. Done.
★★★★★ 4.7 · Free to start · No login · Optional Pro