# ZDNET reviews a free menu-bar tool that shows which Mac apps use the internet, and blocks them > ZDNET reviewed a free per-app firewall for the Mac. What it does, the free tools already built into macOS, and what to check before blocking an app. FireAI Security & Research Team (HisnLabs) · Published 2026-09-28 Canonical: https://hisnlabs.com/en/news/see-which-apps-access-internet-mac-block-them Every app on a Mac can reach the internet unless something tells it otherwise, and most users have no way of knowing which ones do. In a [review for ZDNET](https://www.zdnet.com/home-and-office/networking/firewally-mac-tool-monitor-app-traffic/), Jack Wallen, who has covered Linux and open source since the late 1990s, called a free menu-bar app named Firewally "indispensable" for exactly that reason: it shows which apps are online and lets him switch any of them off. ## Background macOS lets any installed app reach the internet unless something intervenes. The built-in firewall in System Settings › Network › Firewall filters incoming connections; it does not stop an app from connecting out. Seeing what leaves a Mac, and blocking it selectively, requires either a dedicated tool or macOS’s own diagnostic utilities. ## Findings - Firewally is free, installed from the Mac App Store, and runs only in the menu bar as a small shield icon; it has no main window. - It lists apps with their traffic for the past hour, in real time, or for the whole day. - Each app has an on/off switch for internet access, and a default policy decides what happens to apps it has not seen before: let them through, ask, or deny. Wallen recommends switching the default from Pass to Ask. - An "AI summary" for each app explains why it might need internet access; the review does not say where that AI runs. - Settings are minimal: turn the AI summaries off, and launch at login. Wallen’s own use case illustrates the appeal: he runs Ollama, a local AI tool, for privacy, and it needs the internet only to download or update models. Firewally lets him keep it offline the rest of the time and confirm nothing leaves [[1]](https://www.zdnet.com/home-and-office/networking/firewally-mac-tool-monitor-app-traffic/). macOS itself offers two free ways to see the same activity, without installing anything. Activity Monitor, in Applications › Utilities, has a Network tab listing bytes sent and received per process; sorting by "Sent Bytes" shows which apps talk the most. In Terminal, `nettop` shows live network use per process, and `lsof -i` lists every open network connection with the app that owns it. Neither tool blocks a connection; both only show what is happening. > **Note:** The firewall in System Settings › Network › Firewall only controls incoming connections. It does not stop an app on a Mac from connecting out. > FireAI, the on-device firewall for macOS developed by HisnLabs, asks before a newly installed app connects to the internet. A 17-day trial is available. [Download FireAI for Mac](https://hisnlabs.com/en/download) ## Implications for Mac users Anyone curious about what their Mac is doing online can start with the free options: Activity Monitor and Terminal cost nothing and need no install, though neither can block a connection. Firewally adds blocking, in a free package, with the trade-off that its AI summary feature’s data handling is not documented in the review. The choice for most people is between a free on/off switch and a paid tool with more control. ## Recommendations 1. Expect browsers, mail, messaging and cloud-storage apps to need the internet to work; blocking them will simply stop the app. 2. Look up an unfamiliar process name before cutting it off. Apple’s own services often run under names that are not obviously Apple’s, and blocking one for a day is a lower-risk way to see what breaks. 3. Give closer attention to a recently installed app connecting somewhere unexpected than to one used every day with a predictable destination. 4. Set new, unfamiliar apps to "ask" rather than "allow" by default; the first connection is the moment that reveals what an app actually does. ## Relevance to FireAI FireAI does the same core job as the app in the review, per-app control of outgoing connections, and extends it in a few ways. It is not free after its trial, so the relevant question is whether more than an on/off switch is needed. - A new app triggers a [connection prompt](https://hisnlabs.com/en/docs/answer-your-first-connection-prompt) naming the app and its destination, shown on a world map, and "[Why block this?](https://hisnlabs.com/en/docs/why-block-this)" explains what that kind of destination typically receives. - [Per-app rules](https://hisnlabs.com/en/docs/per-app-rules) can be as broad as "off" or as precise as a single domain, so an app can keep its updates while losing its analytics traffic. - For an Ollama-style case, a [timed rule](https://hisnlabs.com/en/docs/timed-rules) can keep an app offline except during chosen hours. - FireAI’s AI [runs on the Mac itself](https://hisnlabs.com/en/docs/on-device-ai-model): a user can ask what an app connected to overnight in plain words, and nothing about those connections leaves the Mac. FireAI does not scan files or remove anything installed on a Mac, and blocking an app’s connections does not stop what the app does offline. If a free on/off switch is enough, the app in ZDNET’s review, or Activity Monitor with some care, may already cover the need. > Leave FireAI on Ask for a day to see which apps on a Mac actually try to reach the internet. A 17-day trial is available. [Download FireAI for Mac](https://hisnlabs.com/en/download) ## Limitations This item relies on a single source. ZDNET’s review does not state where Firewally’s AI summary feature processes data, so whether that specific feature sends anything off the Mac cannot be confirmed either way. The review also does not report on Firewally’s behaviour under heavy network load or test its default-deny mode against a real network filter independently. Try [FireAI, by HisnLabs](https://hisnlabs.com/en/download) free for 17 days. ## Sources - [ZDNET (Jack Wallen), 15 July 2026: This free Mac tool lets me see which apps are quietly accessing the internet, and block them fast](https://www.zdnet.com/home-and-office/networking/firewally-mac-tool-monitor-app-traffic/)