For video calls

Every call gets a report card.

“You froze” again, and the speed test says 500 Mbps. When a call ends, Kilobat tells you how many times it froze and what caused it, so you fix the right thing before the next one.

Download for Mac ↓

$ brew install seifip/kilobat/kilobat

Free forever
Pro $19 once
14-day refunds
macOS 14+
Open-source CLI

Free

228Mbps down↑ 44 Mbps · 24 ms

Stutter test3 spikes

Median5 msp9996 msWorst182 ms

Voice calls
Video · 1080p
Streaming · 4K

Will this call hold up? A speed test for capacity, and a stutter test for the short spikes that speed tests average away.

What it catches

Another app hogging the line. A Dropbox or iCloud upload, a game download or a backup fills your router’s queue, and the call waits behind it. Kilobat names the app.
The Wi-Fi. When your router stalls too, the freeze is in the room: weak signal, a busy channel, or AirDrop scanning, which makes the radio hop channels.
Beyond your router. When the router is fine and nothing else is busy, the delay is with your provider or the call’s server.
The Mac itself. A clean line can still freeze when the CPU is maxed out, memory runs out, the Mac is hot and slows itself down, or the GPU is saturated by video effects. Kilobat says which, and which app used the CPU.

How it works

It notices the call

When Zoom, Microsoft Teams, FaceTime, Slack, Webex, Discord, WhatsApp, Telegram, Signal or a browser on Google Meet uses the microphone, Kilobat starts listening to the line. Not to the call: it never hears or records audio, video or who you talk to.

It watches the line

Once a second it pings the internet and your router, and notes which other apps are busy and how hard the Mac is working. That’s a few kilobytes a minute.

It writes the card

When the call ends you get a notification and a card in Health: ping, jitter, loss, each freeze on a timeline, and what to try. Kilobat Pro names each cause and says what to try; without it you see how many times each call froze.

In the terminal and for agents

kilobat calls lists recent calls with every freeze, its length and its cause, and --json gives the same to scripts. AI agents read it through the MCP tool get_call_reports. Read the docs.

Questions

Does Kilobat listen to my calls?

No. It only sees that an app is using the microphone, which macOS shows anyway. It never opens the microphone, hears audio or knows who you’re talking to. Everything stays on your Mac.

Which apps does it work with?

Zoom, Microsoft Teams, FaceTime, Slack huddles, Webex, Discord, Skype, WhatsApp, Telegram and Signal, plus calls in Chrome, Safari, Arc, Edge, Firefox and Brave, such as Google Meet and Teams on the web.

Why does it freeze when my speed test is fast?

Speed tests measure how much fits through the line, not how steady it is. Calls need every packet on time. One upload in the background or a second of Wi-Fi trouble freezes a call without changing the speed test.

Is it free?

Kilobat counts the freezes for free. Kilobat Pro, $19 once with a 7-day free trial, names each cause and shows what to try.

Get your network out of the dark.

Download for Mac ↓

$ brew install seifip/kilobat/kilobat