CastReader — Read Aloud + AI Explain

Name: CastReader — Read Aloud + AI Explain
Rating: 2.5 (2 reviews)
Author: CastReader

Read Kindle, PDFs, articles and books aloud with synced highlights. AI explains difficult passages. Natural voices in 8 languages.

Overview

Firefox Add-ons Store

Daily users

190 ▼ 14

Data as of 2026-08-04

Rating:

2.50

(2)

Version:

1.2.25

Last updated: 2026-08-01

Features & Capabilities

CastReader helps you stay focused on long content by combining natural text-to-speech, synchronized highlighting, and automatic scrolling. Listen and follow the text at the same time, without losing your place.

Use AI Explain when a passage is difficult. CastReader marks up the original page and walks you through the important ideas without replacing the source text.

What you can do

Read webpages, articles, PDFs, Word files, text files, and Kindle Cloud Reader aloud
Follow synchronized word and paragraph highlights while listening
Ask AI to explain difficult sections on the original page
Automatically extract the main content while skipping navigation and ads
Click a paragraph to continue from that position
Adjust playback speed and choose available voices
Use the document reader without changing the original layout

8 supported reading languages

English, Mandarin Chinese, Japanese, Spanish, French, Brazilian Portuguese, Italian, and Hindi. CastReader detects the content language automatically. English and Chinese include expanded voice choices; the other supported languages use an automatically selected matching voice.

Free and Pro

Start free with 20 minutes of read-aloud and 3 AI Explains each day. Pro unlocks unlimited listening, unlimited Explain, faster playback, and more premium voices.

Privacy

CastReader processes text only when you ask it to read or explain. Anonymous product analytics never includes page text, document content, browsing history, file names, or personal information. Audio is generated on demand.

How to start

Open a webpage, Kindle book, or document.
Click CastReader or the headphone button on the page.
Choose Read Aloud or Explain.
Listen while the original text stays highlighted in sync.

User Growth & Download Statistics

Add-on

By:

Daily users:

Rating:

Version:

1.2.25 Last updated: 2026-08-01

Version code:

6387825

Creation date:

2026-03-16

Risk:

Permissions:

activeTab
storage
scripting
contextMenus
alarms
*://api.castreader.ai/*
*://castreader.ai/*
*://*.cos.accelerate.myqcloud.com/*
*://weread.qq.com/*
*://www.youtube.com/*

Content scripts matches:

<all_urls>
docs.google.com
*.ireader.com.cn
ireader.com.cn
leer.amazon.com.mx
leer.amazon.es
leggi.amazon.it
ler.amazon.com.br
lesen.amazon.de
lezen.amazon.nl

Size:

13.64MB

Email:

su*****@castreader.ai

URLs:

Website

Full description:

Source:

Firefox Add-ons Store

Data ingested on:

2026-08-04

Compare stats and ranking:

Ranking

# 8,194 ▼ 289

Other rankings

#354 in Language Support ▼ 15

#25 in kindle keyword 34 ▲ 1

#103 in reader keyword 58 ▼ 2

#116 in ai keyword 86 ▼ 6

#119 in booking keyword 31 ▼ 2

Upgrade to see more rankings

Other platforms

CastReader — Text to Speech, Read Aloud + AI Explain (v1.2.27)

2,000 4.61

(36)

For Developers

Monetize with App Pass Boost with Extension Booster

Contact the developer

Chrome-Stats does not own this Firefox add-on. Please use these information below to contact the Firefox add-on developer.

Developed by:

CastReader

Firefox Add-ons Store

https://addons.mozilla.org/firefox/addon/castreader-tts-reader/

Email:

su*****@castreader.ai

Website:

https://castreader.com/

Permission Change History

2026-08-01: Version 1.2.22 → 1.2.25

Add Permissions: https://read.amazon.com/* https://read.amazon.co.uk/* https://read.amazon.ca/* https://read.amazon.com.au/* https://read.amazon.co.jp/* https://lesen.amazon.de/* https://read.amazon.de/* https://lire.amazon.fr/* https://read.amazon.fr/* https://leggi.amazon.it/* https://read.amazon.it/* https://leer.amazon.es/* https://read.amazon.es/* https://read.amazon.in/* https://ler.amazon.com.br/* https://read.amazon.com.br/* https://leer.amazon.com.mx/* https://read.amazon.com.mx/* https://lezen.amazon.nl/* https://read.amazon.nl/* https://read.amazon.cn/*

Remove Permissions: *://read.amazon.com/* *://read.amazon.cn/* *://read.amazon.co.uk/* *://read.amazon.ca/* *://read.amazon.co.jp/* *://read.amazon.de/* *://read.amazon.fr/* *://read.amazon.it/* *://read.amazon.es/* *://read.amazon.in/* *://read.amazon.com.br/* *://read.amazon.com.mx/* *://read.amazon.com.au/* *://read.amazon.nl/* *://read.amazon.se/* *://read.amazon.com.tr/* *://read.amazon.ae/* *://read.amazon.sg/* *://read.amazon.pl/* *://read.amazon.eg/* *://read.amazon.sa/* *://leer.amazon.es/* *://ler.amazon.com.br/*

2026-07-16: Version 1.0.2 → 1.2.16

Remove Host permissions: *://api.castreader.ai/* *://castreader.ai/* *://weread.qq.com/* *://read.amazon.com/* *://read.amazon.cn/* http://localhost:18789/* http://localhost:18790/*

Add Permissions: contextMenus alarms *://api.castreader.ai/* *://castreader.ai/* *://*.cos.accelerate.myqcloud.com/* *://weread.qq.com/* *://www.youtube.com/* *://read.amazon.com/* *://read.amazon.cn/* *://read.amazon.co.uk/* *://read.amazon.ca/* *://read.amazon.co.jp/* *://read.amazon.de/* *://read.amazon.fr/* *://read.amazon.it/* *://read.amazon.es/* *://read.amazon.in/* *://read.amazon.com.br/* *://read.amazon.com.mx/* *://read.amazon.com.au/* *://read.amazon.nl/* *://read.amazon.se/* *://read.amazon.com.tr/* *://read.amazon.ae/* *://read.amazon.sg/* *://read.amazon.pl/* *://read.amazon.eg/* *://read.amazon.sa/* *://leer.amazon.es/* *://ler.amazon.com.br/* *://docs.google.com/* <all_urls>

User Reviews

by Ma*****, 2026-07-15

"Error: TTS generation failed for first paragraph: NetworkError when attempting to fetch resource." This is all I get. I'm leaving this at 4* for now as the project is a good one and I don't want to crash it with a first Review, but I'll be back, and for the moment, it doesn't work.

by Ne*****, 2026-06-01

View all user reviews ›

Is CastReader — Read Aloud + AI Explain Safe?

Risk impact

Risk impact measures the level of extra permissions an extension has access to. A low risk impact extension cannot do much harms, whereas a high risk impact extension can do a lot of damage like stealing your password, bypassing your security settings, and accessing your personal data. High risk impact extensions are not necessarily malicious. However, if they do turn malicious, they can be very harmful.

CastReader — Read Aloud + AI Explain requires a lot of sensitive permissions. Exercise caution before installing.

Risk impact analysis details

Critical Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
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High ******* ******* **** *** ****** ***** *** ***** ** ******* **** ********* ********* ** * *********** *****

Risk likelihood

Risk likelihood measures the probability that a Firefox add-on may turn malicious. This is determined by the publisher and the Firefox add-on reputation on Firefox Add-ons Store, the amount of time the Firefox add-on has been around, and other signals about the Firefox add-on. Our algorithms are not perfect, and are subject to change as we discover new ways to detect malicious extensions. We recommend that you always exercise caution when installing a Firefox add-on.

CastReader — Read Aloud + AI Explain may not be trust-worthy. Avoid installing if possible unless you really trust this publisher.

Risk likelihood analysis details

High This extension was recently updated in the past month. New updates may not be stable or safe.
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Medium **** ********* *** ***** ** *** **** * ******* *** ********** *** *** ** ****** ** *****
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