404 uses real ICMP packets — not HTTP workarounds. Get accurate round-trip times, hop-by-hop traceroutes, and packet loss statistics just like you would from a terminal, but with a native iOS and macOS interface.
Perform raw DNS lookups for any record type — A, AAAA, MX, TXT, CNAME, and more. Scan your local network to discover connected devices, open ports, and running services.
See your entire network at a glance. 404 builds an interactive topology map of every device on your network — routers, switches, sensors, smart home devices — with live health indicators and color-coded status tags.
Not sure what a result means? The built-in AI assistant analyzes your ping, traceroute, and DNS results in context and explains what it finds — in plain language. It can suggest next steps and help troubleshoot connectivity issues.
Run lightweight sensor agents on your servers, Raspberry Pi, or Docker containers to monitor your network from multiple vantage points. Results stream back to the 404 app in real time over an encrypted connection.
Servers, VMs, Proxmox
Download (9 MB) Linux ARM64RPi 4/5, ARM servers
Download (8.3 MB) Linux ARMv7RPi 2/3, BeagleBone
Download (8.7 MB) macOSApple Silicon
Download (8.6 MB) Windowsx86-64
Download (9.3 MB) DockerAlpine-based, ~16 MB
View on Docker HubYes. 404 sends real ICMP echo requests, giving you accurate round-trip times, TTL values, and packet loss statistics — the same data you would get from a terminal ping command.
Yes. 404 can discover devices on your local network, identify open ports, and detect running services. It works on any Wi-Fi network your iPhone or Mac is connected to.
404 supports A, AAAA, MX, TXT, CNAME, NS, SOA, SRV, and PTR record types. You can query any DNS server, not just your default resolver.
The core tools — ping, traceroute, DNS, and network discovery — are completely free. 404 Pro unlocks advanced features like topology mapping, remote sensors, and AI-powered analysis with a monthly ($2.99) or annual ($19.99) subscription.
The 404 sensor is a single static binary with no dependencies. It runs on Linux (x86-64, ARM64, ARMv7), macOS (Apple Silicon), and Windows (x86-64). A Docker image is also available for containerized deployments.
Sensors connect to the 404 app over a TLS-encrypted channel. You pair a sensor by running 404-sensor pair and entering the code shown in the app. Once paired, the sensor streams check results in real time. If the connection drops, results are buffered locally and synced when reconnected.
Yes. 404 is a native app for both iOS and macOS, with an adaptive interface that takes full advantage of each platform. The macOS version supports all the same diagnostic tools as the iOS version.
