ICMP ping & traceroute
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.
- Real ICMP ping with RTT, jitter, and packet loss
- Visual traceroute with hop-by-hop latency
- Continuous ping with live charting
DNS queries & network discovery
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.
- Raw DNS queries with full record detail
- Local network device discovery
- Port scanning & service detection
Topology mapping
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.
- Interactive node-graph topology view
- Live health rings and latency indicators
- Save and restore layout presets
- Export topology as PNG or CSV
Diagnostic assistant
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.
- Context-aware result analysis
- Plain-language explanations
- Troubleshooting recommendations
Deploy sensors anywhere
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.
- Cross-platform: Linux, macOS, Windows
- ARM support for Raspberry Pi and SBCs
- Docker-ready with Alpine-based image
- TLS-encrypted sensor-to-app protocol
- Offline buffering — results sync when reconnected
Supported platforms
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 HubQuick start
Common questions
Yes. 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 is a one-time $19.99 unlock for the full toolkit, unlimited saved devices, topology mapping, remote sensors, and 30-day history. 404 Pro+ adds the AI Assistant, live CVE intelligence, sensor cloud, and advanced pentest flows for $4.99/month or $39.99/year (with a 7-day free trial).
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.