Listen to Slack Messages
CastReader reads Slack channel messages, announcements, and threads aloud with natural voices — turn your workspace backlog into a hands-free morning briefing.
Shipping note: we moved the rate-limiting logic into the edge layer this week. The observable effect is that P99 latency on /search dropped from 420ms to 180ms. Most of the win came from not waking up the DB for rate-limit decisions. Docs updated in the wiki — ping me if you want the design memo.
Reads the message body — avatars, timestamps, reactions are skipped
How CastReader Works with Slack
Built for the way teams actually use Slack — scan morning, catch up later
Announcement Channels
🔊 #engineering-updates as Audio Standup
Your workspace's read-only announcement channel is the best use case. Click Listen and CastReader reads every message in order, each with author and then message body. No scrolling, no missed updates — morning commute becomes async standup.
Threaded Replies
Full Thread Read, Not Just Parent
Slack threads hide replies behind a click. CastReader reads the parent, then optionally walks through every reply in order. Perfect for catching up on overnight design discussions without scrolling through 40 nested messages.
Code and Snippets
Code Blocks Announced, Not Spelled Out
Eng Slack is half code. CastReader announces 'code block, N lines' and moves on — you hear the surrounding human explanation, not every bracket read aloud. Fenced multi-line snippets and inline `code` are both handled.
Huddles and Canvas Skipped
Chrome Filtered Automatically
Huddle invitations, Canvas previews, app integrations (Google Calendar cards, GitHub PR unfurls, Workflow Builder prompts) — CastReader's Slack extractor recognizes these as chrome and skips them. Human-written messages get read; bot noise does not.
Frequently Asked Questions
Everything you need to know about listening to Slack with CastReader
Does Slack have a built-in read-aloud feature?
No. Slack has no text-to-speech for messages. CastReader adds a 🔊 Listen button on every message so you can hear any channel, thread, or DM read aloud for free.
Does it work on a paid Slack workspace?
Yes. CastReader works on any Slack workspace you can access in your browser — free, Pro, Business+, Enterprise Grid. No admin approval or workspace installation required; it's a browser extension, not a Slack app.
Is my data sent anywhere?
Audio generation happens on our TTS server (required for the natural voices). Message text is sent to generate audio and is not stored. For sensitive workspaces, review CastReader's privacy docs before enabling — or use Slack's desktop app instead of the browser when you don't want CastReader touching certain messages.
Does it work in the Slack desktop app?
No — the Slack desktop app is a native Electron app that doesn't load browser extensions. CastReader works on app.slack.com in your browser. Most modern Slack users can use either and keep the browser tab for read-aloud sessions.
Can I listen to DMs?
Yes. Direct messages and private group DMs work the same way as channels. Audio plays only in your browser and is not shared with anyone else.
Does it handle @mentions and user IDs?
Yes. @mentions read as the person's display name ('Alice Chen' not '@U02ABCDEF'). #channel references read as the channel name without the hash character. :emoji: shortcodes read as the emoji name at normal pace.
Is it free?
Completely free. No API key, no usage limits, no account required. Install the Chrome extension and start listening.
Also Try
Start Listening Now
Completely free. No workspace admin approval needed. Install and start listening.