Listen to Substack Newsletters

Turn any Substack article into natural-sounding audio. Just open the newsletter in Chrome, click CastReader, and listen.

100% FreeNo Login RequiredUnlimited UsagePrivacy First

Why Listen to Substack with CastReader?

The easiest way to consume newsletters hands-free

One Click

Instant Audio from Any Newsletter

Open any Substack post in Chrome or Edge, click the CastReader icon, and it starts reading aloud instantly. No copy-paste, no setup.

One click audio conversion

Natural Voices

AI Voices That Sound Human

Powered by the Kokoro AI model, CastReader's voices sound natural and expressive — not robotic. Choose from voices in 40+ languages.

Natural AI voices

Follow Along

Paragraph Highlighting

CastReader highlights the current paragraph as it reads, so you can follow along visually or jump to any section with a click.

Paragraph highlighting

100% Free

No Limits, No Account

Completely free with no usage limits. No signup, no subscription, no hidden fees. Just install and start listening.

Free unlimited usage

Frequently Asked Questions

Everything you need to know about listening to content with CastReader

How do I listen to a Substack newsletter?

Install CastReader from the Chrome Web Store, open any Substack article in your browser, and click the CastReader icon. It will start reading the article aloud with natural AI voices.

Does this work with paid Substack articles?

Yes. As long as you can see the article in your browser (i.e., you're a paid subscriber and logged in), CastReader can read it aloud.

Is CastReader free?

Yes, completely free with no limits. No account needed, no subscription, no usage caps.

Can I adjust the reading speed?

Yes. The floating player lets you speed up or slow down playback to match your preference.

Does it highlight the text as it reads?

Yes. CastReader highlights the current paragraph and auto-scrolls so you always know where you are in the article.

What languages are supported?

CastReader supports 40+ languages with natural AI voices, so it works with Substack newsletters in virtually any language.

Does it work on the Substack app?

CastReader is a browser extension for Chrome and Edge. Open your Substack newsletters in the browser instead of the app to use it.

Is my data private?

CastReader reads the text on the page you're viewing and sends it to our AI voice API — that's it. We don't store your browsing history or any personal data.

Start Listening Now

Completely free. No signup. No limits. Install and start listening.