Is there a good tool for monitoring network activity on Mac OS X?

Question

Is there a good bit of software on Mac OS X that I can use to monitor incoming and outgoing network activity? Nothing too geeky, I just want something simple to use.

I'm on version 10.6 (Snow Leopard) if that helps.

Solution 1

Wireshark is widely acknowledged as one of the best network monitor tools available. Distributions are available for OS X.

If you prefer something more simplistic you can use iStatMenus to show incoming / outgoing network traffic speeds.

For the person who doesn't want to install anything you can also use tcpdump in Terminal.

tcpdump -i [interface, en0 is ethernet, en1 is wireless]

Solution 2

Also check out nettop, a little command line gem that ships with Mac OS.

Solution 3

Also look at MenuMeters. I tried iStat Menus & MenuMeters and preferred MM. Not saying one is better; just that there are a couple of choices.

A working version of MenuMeters for El Capitan can be found here.

Solution 4

LittleSnitch! - 30$

It is mainly a software Firewall that may help you to prevent some apps to access the internet. It also has a nice menubar icon with live network usage. Mouseover on it and it displays which app is communicating with which server or ip address.

I have LittleSnitch and iStat Menus installed. Both are complementary.

Solution 5

Commercial (16$) iStat Pro and iStat Menus (dashboard widget and menu bar item respectively) are great for monitoring everything from network activity to CPU temperatures.

And of course there's the network tab of Activity Monitor.

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Comments

[xentek]

iStatMenus looks like the day to day winner, but I also appreciate the terminal command too for the quick/dirty way of doing it.

[Josh K]

LittleSnitch will be a pain unless you're explicitly blocking stolen / cracked programs from calling home. Also the menu item is not nearly as informative as iStat. You'd have to open up the Network Monitor screen to get any benefit.

[ankhuri]

Well, there is a lot of programs that are calling home and should not. If you are a bit concerned about security you will understand what I mean. The LittleSnitch's mouseouver pop-up is also great for showing realtime process-host network activity. But yes, it is not as informative as iStat. That's why i use both.

[cOle2]

+1. MenuMeters beats iStat Menus anyday.

[vy32]

Wireshark is a packet analyzer with delusions of grander. It doesn't give a good view of everything going on, but it's great for going through packets with a hex editor.

[Michael H.]

tcpdump is what I need here - for some reason, Private Eye wasn't showing me FTPS passive connections, but tcpdump did.

[slm]

Good first post. To round out your answer perhaps you could include a link to the app and a screenshot? Just a thought.

[Ashley]

MM is also open-source.

[Jonathan Nicol]

+1 For mentioning Activity Monitor. For anyone with casual requirements who just needs to know their up/down speed this is a great solution, and it ships free with OS X.

[rinogo]

Tempted to downvote... How does this help "monitor incoming and outgoing network activity"? (If it does, please let me know; I'd love to use it!)

[Anton Matosov]

There is a useful 'delta output' mode which can be toggled with the 'd' key while app is running. It will show you the actual download/upload rates per second per connection.

[Henrique de Sousa]

Light, functional and open-source application. What more can we ask? :)

[jfountain]

Unfortunately this no longer works as of osx 10.11.1 El Capitan.

[boot13]

I can confirm that the version of MenuMeters for El Capitan at member.ipmu.jp/yuji.tachikawa/MenuMetersElCapitan works as expected on that O/S.

[matty]

I don't think this does what you think it does. This tool (command is /System/Library/CoreServices/Network\ Diagnostics.app/Contents/MacOS/Network\ Diagnostics) diagnosis WiFi or Ethernet connection issues. It doesn't monitor network activity.

[MrG]

Pressing the 'd' key didn't do anything for me (macOS 10.12.3) until I first ran nettop -d. It may have been that my terminal window wasn't wide enough initially. Pressing 'h' while running displays other available options.

[nyxee]

little snitch currently shows me my network history graph for one hour. is MenuMeters and Istat show less. do we have anything that shows more than 1 hour, say one day or a week?

[JRobert]

Still fully functional in Sierra 12.6.

[John Mark Mitchell]

iStat Pro no longer appears to be supported.

[John Mark Mitchell]

The URL provided is dead. The URL for Net Monitor and Net Monitor Sidekick has been updated to netmonitor.s3-website-us-east-1.amazonaws.com

[navigaid]

Try brew cask install menumeters if you use brew package manager

[JRobert]

Still working in Mojave 10.14.6

[Itachi]

Thanks for your sharing! This is exactly what I am looking for a long time!

[Marcello Romani]

nettop -t wifi -P has proven a good default for me.