Scapy

Summary

Scapy is a free Python program and library for manipulating network packets: it can create or decode them, send and capture them, and match requests with replies. It works as either an interactive shell or a library, and supports tasks such as scanning, tracerouting, probing, unit tests and network discovery. Users can set packet field values and combine protocol layers rather than depend on fixed templates. After a probe, Scapy returns decoded packets before interpretation, leaving them available for analysis. It can read and store pcap files and inject invalid frames and custom 802.11 frames. Documentation covers adding protocols and extending Scapy with add-ons, as well as installation, usage, troubleshooting and its API. It runs on Linux, macOS, BSD and Windows; Windows installation requires Npcap. Plotting requires Matplotlib, while TLS decryption and PKI operations require the cryptography package. Scapy's code, tests and tools are licensed under GPL v2, and its documentation under CC BY-NC-SA 2.5.

Who it is for

Scapy suits developers, IT and network professionals, researchers, system administrators, and telecommunications users who need customizable packet manipulation and network probing.

Compared on network protocol analyzers

Free plan

Yesscapy.net

Traffic decryption

Yesscapy.net

Facts

Purpose

Scapy is a Python packet manipulation program and library that can forge or decode packets, send and capture them, and match requests with replies.github.com · 30 Sept 2026

Shell and library

Scapy can be used as an interactive shell or as a library.github.com · 30 Sept 2026

Network tasks

The project lists scanning, tracerouting, probing, unit tests, and network discovery among Scapy’s uses.github.com · 30 Sept 2026

Packet handling

Scapy can read and store packets in pcap files and can inject invalid frames and custom 802.11 frames.github.com · 30 Sept 2026

Protocol extensions

The documentation includes instructions for adding new protocols and extending Scapy with add-ons.scapy.readthedocs.io · 30 Sept 2026

Platform support

Scapy runs on Linux, macOS, BSD, and Windows; Windows installation requires Npcap.scapy.readthedocs.io · 30 Sept 2026

Optional dependencies

Plotting requires Matplotlib, while TLS decryption and PKI operations require the cryptography package.scapy.readthedocs.io · 30 Sept 2026

Security reporting

GitHub’s security page says the project has not set up a SECURITY.md file and provides a vulnerability reporting link.github.com · 30 Sept 2026

License

Scapy’s code, tests, and tools are licensed under GPL v2.github.com · 30 Sept 2026

Intended audiences

The project metadata lists developers, IT, science and research, system administrators, and telecommunications as intended audiences.github.com · 30 Sept 2026

Documentation

The project provides online documentation with installation instructions, usage guides, troubleshooting, and an API reference.scapy.readthedocs.io · 30 Sept 2026

Use cases

Scapy supports scanning, tracerouting, probing, unit tests, attacks and network discovery.scapy.readthedocs.io · 2 Oct 2026

Interactive modes

Scapy can be used as an interactive shell or as a library.github.com · 2 Oct 2026

Packet flexibility

Users can set arbitrary field values and stack protocol layers without predetermined templates.scapy.readthedocs.io · 2 Oct 2026

Raw results

After a probe, Scapy returns the full decoded packets before interpretation so users can analyze them in different ways.scapy.readthedocs.io · 2 Oct 2026

Python DSL

Scapy uses Python syntax and interpreter capabilities as a domain-specific language for describing packets.scapy.readthedocs.io · 2 Oct 2026

Platforms

Scapy runs on Linux, macOS, BSD and Windows; Windows installation requires Npcap.scapy.readthedocs.io · 2 Oct 2026

Installation

The latest release can be installed with pip install scapy, and it can also run from the run_scapy or run_scapy.bat scripts without installation.scapy.readthedocs.io · 2 Oct 2026

Optional integrations

Optional features can use Matplotlib, PyX, Graphviz, ImageMagick, VPython-Jupyter and cryptography.scapy.readthedocs.io · 2 Oct 2026

Licensing

Scapy code, tests and tools are licensed under GPL v2, while its documentation is licensed under CC BY-NC-SA 2.5.github.com · 2 Oct 2026

Security support

Critical bugs should be reported privately through GitHub's security tab, and the project supports only the latest Scapy master version.github.com · 2 Oct 2026

Release

Scapy documentation lists release 2.7.1 dated October 1, 2026.scapy.readthedocs.io · 2 Oct 2026

Audience

Scapy is intended for users who need customizable network probing and packet manipulation tools rather than fixed-purpose utilities.scapy.readthedocs.io · 2 Oct 2026

Where it ranks on Samsung Mobile US Press

• Best Network Protocol Analyzers in 2026#3 of 29

Sources

• github.com/secdev/scapy· checked 30 Sept 2026
• scapy.readthedocs.io/en/latest/· checked 30 Sept 2026
• scapy.readthedocs.io/en/latest/installation.html· checked 30 Sept 2026
• github.com/secdev/scapy/security/policy· checked 30 Sept 2026
• github.com/secdev/scapy/blob/master/pyproject.toml· checked 30 Sept 2026
• scapy.readthedocs.io/en/latest/introduction.html· checked 2 Oct 2026
• scapy.readthedocs.io/en/stable/installation.html· checked 2 Oct 2026
• github.com/secdev/scapy/blob/master/SECURITY.md· checked 2 Oct 2026
• scapy.net· checked 2 Oct 2026