Sniffnet

Sniffnet is a free, open-source network monitor for people who want to understand traffic without starting with a command-line workflow. It is strongest as a visual overview and capture-file companion; it is not suitable when decrypting traffic is essential.

Overview

Sniffnet brings live monitoring, host details, alerts, and offline trace analysis together in a desktop app for Windows, macOS, and Linux. Choose an adapter, filter observed traffic, and follow overall statistics and real-time traffic-intensity charts. That is a useful combination for spotting changes in activity and investigating where bandwidth is going, though the lack of decryption rules it out for inspecting encrypted content.

Most functionality relies on offline databases. Sniffnet processes incoming traffic as needed and uses reverse DNS lookups to provide hostnames for IP addresses. A 2025 security audit covered static and dynamic analysis, dependency checks, fuzzing, and interactive testing; its only relevant finding was low severity and had been fixed.

Key features

• Live traffic and capture files: Select an adapter, apply display filters, and capture traffic. Sniffnet reads PCAP, PCAPNG, and CAP files, and can export reports as PCAP. This makes it useful for moving between a live view and saved traces, with PCAP as the export format.
• Host and service details: The app identifies local connections, shows remote hosts’ geographical locations, and can find domain names and ASNs. It recognizes more than 6,000 upper-layer services, protocols, trojans, and worms, giving a broad set of labels for interpreting observed activity.
• Program monitoring: See which programs use network bandwidth and save favorites. This is especially relevant when the question is which application is responsible for traffic, rather than only how much traffic is moving.
• Alerts and blacklists: Configure notifications for network events and import custom IP blacklists to highlight potentially dangerous connections. These tools add focused attention to monitoring, but do not change the app’s inability to decrypt traffic.
• Customization: Custom themes and 26 languages make the interface adaptable to different preferences and users.
• Command-line support: Sniffnet includes a command-line tool and command-line capture alongside its graphical monitoring features.

Pricing

Sniffnet costs free. The Sniffnet plan is fully free and open-source under MIT or Apache-2.0, with application monitoring, bandwidth alerts, live capture, offline trace analysis, and capture-file support included. There is no paid tier to weigh against the free plan, and no trial is needed to access the software.

This is a strong fit for individuals who want a capable desktop monitor without a license fee. Its principal trade-off is functional rather than commercial: traffic decryption is not included, so users who need that capability should choose another analyzer.

Platforms

Sniffnet runs on Windows, macOS, and Linux. Persistent installation problems or questions can be taken to an issue on the project.

Who it's for

Sniffnet suits people who want a visual way to monitor bandwidth, identify hosts and services, and see which programs are using the network. Its mix of live charts, alerts, and offline trace analysis can serve newcomers as well as users who need a lightweight monitoring view. Choose another tool if decrypting traffic is central to the work.

Pros and cons

• Pro: Live charts, program monitoring, host details, alerts, and offline analysis are combined in a free desktop application, covering several common monitoring tasks without separate paid plans.
• Pro: PCAP export plus PCAP, PCAPNG, and CAP reading make it practical to examine saved traces as well as live activity.
• Pro: The 2025 audit’s only relevant finding was low severity and had been fixed.
• Con: Sniffnet does not decrypt traffic, a decisive limitation for users who need to inspect encrypted content.
• Con: Hostnames rely on reverse DNS lookups, so hostname information is tied to that lookup method.

Alternatives

For more options, browse Network Packet Capture Software, Bandwidth Monitoring Software, or Network Packet Analyzer Software.

• Termshark is another free option across Android, Linux, macOS, and Windows; it requires tshark in PATH, and some tshark features are not exposed.
• Malcolm is a free, self-hosted alternative for readers who want software available across web and API platforms as well as desktop operating systems.
• NetworkMiner is a freemium alternative with a free edition and GPLv2 open-source code.
• tcpdump is a free alternative for readers considering a BSD-licensed tool; capture permission depends on operating system and configuration.
• TShark is a free alternative from the Wireshark project, maintained by the Wireshark Foundation, a nonprofit supported by donations.
• Wireshark is a free full version with no license fee.
• Arkime is free, open source, and self-hosted, with no paid-only features or license fees.
• Colasoft Capsa has a free edition limited to 10 monitored IP addresses, four-hour sessions, and no WiFi connection monitoring; its Professional plan costs $695, paid once.

Verdict

Choose Sniffnet if you want a free, cross-platform visual monitor that combines live traffic, program usage, host details, alerts, and capture-file analysis. Its breadth and open-source pricing make it a practical starting point for network visibility. Look elsewhere if traffic decryption is a requirement.