Free · macOS 14+ · nothing leaves your Mac

Where your gigabytes
actually went.

Sysline sits in the menu bar and records what every app sends and receives. Open it and the month is already there, app by app, day by day.

Download for macOS Apple Silicon

The installer clears the first-launch warning for you.

now down
1.8 MB/s
now up
0.32 MB/s
today
1.94 GB

The menu bar shows the live rate. Everything else is one click away.

Live rate
Down and up per second, in the menu bar or a floating window.
Per app
Every app and background process, sorted by what it used.
History
Today, a week, 90 days, or everything you have recorded.
Speed test
Download, upload and ping, kept with the rest of your history.
Live rate

A number you can
glance at.

The menu bar carries the current rate. Click it for today's totals and the top apps, or pull out the floating window and keep it in a corner while you work.

Down, up, or both — your choice of what the bar shows
A floating window that can stay above other apps, or behave like a normal one
It remembers where you left it
SyslineToday
1.94 GB
0.71 GB

Pinned above everything, or tucked behind — one toggle.

App↓ In↑ OutTotal

Sorted by total — in the app, any column will do.

Per app

Down to the process
that did it.

Not just Chrome and Slack. Background processes get named too, so when something quietly uses a gigabyte overnight you can see which one.

Search by app, sort by download, upload or total
Filter by the network you were on
Real process names, not one big "Other" bucket
History

The month is
already there.

Sysline records from the moment you install it, so the answer to "what happened last Tuesday" is waiting for you. Days are split at your local midnight, not somewhere else's.

Set a monthly cap and Sysline tells you at 80% and 100%, once each.

Download Upload

Seven days, split at your local midnight.

The part other monitors get wrong

It counts what actually
left your Mac.

Traffic between apps on your own machine — a simulator streaming its screen, a local database, a dev server — never touches your connection. Most tools count it anyway, and your day reads 270 GB.

Sysline measures only the real interfaces: Wi‑Fi, ethernet, hotspot, VPN. Your data plan and your history agree.

Counted by others 270 GB
Actually left the Mac 1.9 GB

One day with an Android emulator open. The same day, measured two ways.

61.4
Mbps
61.4 down 22.8 up 38 ms
Browsing
Gaming
Streaming
Video calls

A finished test, as the app shows it.

Speed test

Is it your line,
or just that site?

Run a test from the menu bar and you get more than two numbers: download, upload, ping and jitter, then a verdict on what the connection can actually carry. One dial covers a slow café hotspot and a gigabit line.

Download, upload, ping and jitter
Scored out of five for browsing, gaming, streaming and video calls
Results kept with the network and provider they came from
Runs from the menu bar without opening the app
Where it all lives

On your Mac. That's the whole list.

One file, yours

Everything sits in a single database in your Application Support folder. No server, no account, no sign-in.

Nothing phones home

Sysline talks to the network for two things only: a speed test you started, and checking whether a new version exists.

It stays small

Detailed samples are kept for two days and then folded into hourly totals, so a year of history is still a few megabytes.

Put it in your menu bar.

Free and open source. No account, no tracking, no subscription.

Download Sysline.dmg

Sysline is not notarized yet. The installer clears the warning for you; if you use the DMG or brew, approve the first launch once in System Settings → Privacy & Security → Open Anyway.

Apple Silicon · updates in place