Best Windows Free Open-Source Security Software

Private, end-to-end encrypted messaging.

Secure dotenv for developers

Cross-platform password manager compatible with Keepass 2.x

Simple vaultless password manager in Go

An open platform for various uses

Patch-level verification for Bundler

General purpose TLS and crypto library

Interactive, scriptable man‑in‑the‑middle proxy for HTTP, HTTPS and WebSocket traffic

Unified XDR and SIEM protection for endpoints and cloud workloads

Run data science on remote data without moving it.

Fast and secure backup and versioning for files and directories

Fast, secure, efficient backup program

High-performance reverse proxy for NAT traversal

A secure password manager for teams

Generate Software Bill of Materials from container images and filesystems

Free backup software to store encrypted backups online

A modern, secure password manager

Advanced offline password cracker supporting hundreds of hash types

Stateless password manager

Open-source antivirus engine for detecting malware across platforms

A note-taking app with a focus on security and simplicity

Lightweight Intranet Penetration Proxy Server

Secure, private budgeting for individuals and households

Secure, fast file transfers from the command line