Why is your coworker always green on Slack, but never responds?

Almost everything written about a Slack dot is aimed at the person wearing it: how to look active, how to fake a status, how to avoid getting flagged. This is the other side of that question, the one you actually have when you're staring at someone else's green dot and a message that's been sitting unanswered for two hours.

Common reasons for a green status that doesn't match a reply

Google's own AI Overview for this exact question lands on a similar shortlist, here's what each one actually looks like in practice:

Mouse jigglers and cursor shakers

The most literal explanation: software or a small USB dongle nudges the cursor every so often, just enough to reset Slack's 30-minute idle timer without anyone touching the keyboard. It's common enough that we've written entire buying guides on it, see our roundup of the most-used mouse jiggler software or the Mac-specific options if that's the platform in question. The tell is consistency: a jiggler keeps someone green through lunch, meetings, and gaps where a person would normally step away.

Awake utilities, and why most of them don't actually explain this

Apps like Caffeine or the Terminal's caffeinate command, and Windows tools like PowerToys Awake, stop a computer from sleeping. It's tempting to assume one of these is why a coworker's dot never goes grey, but for most of them that's not actually how it works: these tools issue a power-management assertion, not a simulated keypress or mouse move, so they keep the machine awake without resetting Slack's own input-based timer. See our breakdown of why caffeinate and Caffeine-style apps don't keep Slack active for the mechanics. If someone's status genuinely stays green for hours with zero replies, an awake utility alone usually isn't the explanation, a jiggler or an always-active app is the more likely culprit.

The mobile app, left open

Unlike desktop, Slack's mobile app has no 30-minute grace period, someone is Active only while the app is genuinely in the foreground. But "foreground" is a lower bar than it sounds: a phone left unlocked on a desk with Slack still open, or a tablet propped up nearby, can register as active without anyone looking at it. See how Slack's mobile presence actually works for exactly when it does and doesn't count.

Deep work, or a real break, while still technically "active"

The least suspicious explanation is also the most common one: someone touched their keyboard 25 minutes ago, stepped away to think, grab coffee, or sit in a meeting with their laptop open, and the 30-minute window simply hasn't expired yet. A green dot reflects the last half hour, not this exact second, so a short gap between "active" and "responsive" is completely normal and doesn't require any explanation at all.

How Slack actually calculates activity

It's worth knowing the mechanism, since almost every reason above traces back to it. On desktop, Slack watches for mouse movement and keystrokes and keeps you Active for up to 30 minutes after the last one, then flips you to Away automatically, see our full Slack active status explainer for the exact rules. On mobile, there's no timer, you're Active only while the app is open in the foreground and Away the instant you background it. And a status with a small clock icon isn't Away at all, it's Do Not Disturb, see what the Z icon actually means if that's what you're looking at.

How to actually get a response

None of the above is really about catching anyone out, most of the time a green dot without a reply is completely explainable and not worth reading into. If you genuinely need an answer, a few things work better than watching the dot:

• Send a direct question, not a status check. "Can you approve the PR when you get a sec?" gets a faster reply than "you there?", since it doesn't require them to context-switch just to respond to your first message.
• Use a real urgency signal if it's actually urgent. Slack's @here or @channel, or a DM with a clear deadline in it, cuts through more reliably than assuming presence equals availability.
• Give it the same 30-minute benefit of the doubt the dot itself uses. If someone was active 10 minutes ago and hasn't replied, that's normal, not a red flag, follow up after the same kind of window Slack itself waits before marking someone away.
• Ask synchronously if it's genuinely time-sensitive. A quick call or a walk to their desk beats an increasingly pointed follow-up message every time presence is the actual blocker.

FAQ

What does it mean if someone is green on Slack?
It means Slack detected mouse or keyboard input on their desktop in the last 30 minutes, or their mobile app is open in the foreground. It doesn't mean they've seen your message or are available right now.

How long do you stay green on Slack?
Up to 30 minutes after the last desktop input, then Slack flips to Away automatically. On mobile there's no timer, you're active only while the app is open in the foreground.

How to tell if someone is active on Slack?
The dot next to their name is the only signal: solid green for Active, a hollow ring for Away. There's no reliable way to see whether they've read a specific message beyond that.