Sniffnet

Sniffnet is a free, open-source desktop network monitor for people who want a readable view of traffic, hosts, and the programs using bandwidth. Its combination of live monitoring and offline capture analysis is unusually broad for a no-cost tool, but it is not the right choice when traffic decryption is essential.

Overview

Sniffnet brings live traffic statistics, host information, alerts, and capture-file analysis into one application. You can select a network adapter, filter observed traffic, and follow traffic intensity in real time. That makes it useful for understanding activity on a connection without needing to start with a command-line workflow. It does not decrypt traffic, so users who need to inspect encrypted content should choose another tool.

Most functionality is provided through offline databases; the app also processes incoming traffic as needed and makes reverse DNS lookups to show 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

• Traffic monitoring: Overall statistics and live intensity charts help reveal changes in bandwidth use. Application monitoring identifies programs using network bandwidth, and saved favorites make recurring attention easier.
• Capture and analysis: Sniffnet supports live capture and offline trace analysis, with display filters and protocol dissectors. It reads and writes PCAP files and reads PCAPNG and CAP files, so it can work with common capture material while limiting export to PCAP.
• Host and service details: The app can identify local connections, show remote hosts’ geographic locations, and find domain names and ASNs. Detection covers more than 6,000 upper-layer services, protocols, trojans, and worms, giving users useful context for observed connections.
• Alerts and customization: Configurable network-event notifications and imported custom IP blacklists help draw attention to connections of interest. Custom themes and 26 languages add flexibility without changing the core monitoring workflow.
• Command line: Sniffnet includes a command-line tool and command-line capture, alongside its desktop interface.

Pricing

Sniffnet is fully free and open source under MIT or Apache-2.0, at no cost. There is no paid tier or free-trial decision to navigate. Users get live capture, application monitoring, bandwidth alerts, and the same capture and analysis capabilities without a subscription; the principal functional limitation is the absence of traffic decryption.

Platforms

Sniffnet runs on Windows, macOS, and Linux. The download page directs people with persistent installation problems or questions to open an issue, a practical support route for a free open-source application.

Who it's for

Sniffnet suits home users, curious learners, and administrators who want to see bandwidth patterns, identify hosts and programs, or review capture files through a visual desktop app. Its maker aims to make network analysis approachable even for people who find other analyzers difficult. It is less suitable for investigations that depend on decrypting traffic or for anyone who needs a different platform than Windows, macOS, or Linux.

Pros and cons

• Pro: Live charts, program-level bandwidth monitoring, alerts, host context, and offline capture analysis put several useful network tasks in one free tool.
• Pro: PCAP read/write plus PCAPNG and CAP reading gives it flexibility for working with capture files.
• Pro: The 2025 audit found only a low-severity relevant issue, which had been fixed.
• Con: No traffic decryption means it cannot meet needs that require inspecting encrypted traffic.
• Con: Capture export is PCAP; PCAPNG and CAP are read-only formats in Sniffnet.

Alternatives

For a wider shortlist, browse Network Packet Capture Software, Network Packet Analyzer Software, and Bandwidth Monitoring Software.

• Termshark is another free option across Android, Linux, macOS, and Windows, but it requires tshark in PATH, a supported tshark version, and does not expose every tshark feature.
• Malcolm is a free, self-hosted, open-source alternative for readers who want that deployment model.
• NetworkMiner offers a free edition and GPLv2 open-source code for readers considering a freemium alternative.
• tcpdump is a free BSD-licensed alternative for readers who prefer a command-line capture tool; capture permission depends on the operating system and configuration.
• TShark is a free GPL v2 alternative from the Wireshark project for readers considering that project’s command-line tool.
• Wireshark is a free full-version alternative with no license fee.
• Arkime is a free, open-source option for readers seeking a self-hosted web-based tool with no paid-only features or license fees.
• PCAPdroid is an Android alternative with free core monitoring and capture; its paid features are a one-time purchase.

Verdict

Choose Sniffnet if you want a free desktop app that combines live bandwidth monitoring, host and service identification, alerts, and practical capture-file analysis. Its approachable visual focus and broad feature set make it a strong fit for routine network visibility across Windows, macOS, and Linux. Look elsewhere when traffic decryption is a requirement.