Browse free open source Security software and projects for Windows and Android below. Use the toggles on the left to filter open source Security software by OS, license, language, programming language, and project status.

  • Ship Agents Faster Icon
    Ship Agents Faster

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    A low-code dashboard makes monitoring intuitive for any admin, while scripting and custom sensors give experts full control.

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  • 1
    frida

    frida

    Dynamic instrumentation toolkit for developers

    Dynamic instrumentation toolkit for developers, reverse-engineers, and security researchers. Inject your own scripts into black box processes. Hook any function, spy on crypto APIs or trace private application code, no source code needed. Edit, hit save, and instantly see the results. All without compilation steps or program restarts. Works on Windows, macOS, GNU/Linux, iOS, Android, and QNX. Install the Node.js bindings from npm, grab a Python package from PyPI, or use Frida through its Swift bindings, .NET bindings, Qt/Qml bindings, or C API. Frida is and will always be free software (free as in freedom). We want to empower the next generation of developer tools, and help other free software developers achieve interoperability through reverse engineering. We are proud that NowSecure is using Frida to do fast, deep analysis of mobile apps at scale. Frida has a comprehensive test-suite and has gone through years of rigorous testing across a broad range of use-cases.
    Downloads: 198 This Week
    Last Update:
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  • 2
    Lantern

    Lantern

    Tool to access videos, messaging, and other popular apps

    Can't access your favorite apps? Download Lantern to easily access videos, messaging, and other popular apps while at school or work. Lantern is an application that allows you to bypass firewalls to use your favorite applications and access your favorite websites. Lantern does not cooperate with any law enforcement in any country. Lantern encrypts all of your traffic to blocked sites and services to protect your data and privacy. Lantern passed multiple third party white box security audits to ensure security of our code. Lantern is easy to use, just download and install to start streaming, browsing and using apps, no configuration required. No installation, no registration, no registration, no configuration, just click and go! All you have to do is install it and hit the POWER button! Don't wait forever for your applications to load or the website to appear in your browser. Connect with Lantern and get there fast!
    Downloads: 88 This Week
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  • 3
    Blokada Apps

    Blokada Apps

    Repo for Blokada apps

    Blokada is the popular ad blocker and privacy app for Android and iOS. It's being supported and actively developed by the amazing open-source community. Our modern solution for mobile content blocking. Protect multiple devices from ads and tracking, and manage your preferences in one place. Enjoy zero battery drain, no noticeable slowdowns, and highly reliable adblocking. If you want to efficiently block ads, trackers, malware, save on your data plan, speed up your device and protect your privacy with just one application, then Blokada is for you. It is free, secure and open source. For ultimate privacy protection, upgrade to Blokada Plus and connect through our VPN. Available in both Blokada 6 and Blokada 5. We use WireGuard®, the most advanced VPN protocol, to encrypt your network activity and hide your IP address.
    Downloads: 74 This Week
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  • 4
    SoftEther VPN

    SoftEther VPN

    Cross-platform multi-protocol VPN software

    An open-source free cross-platform multi-protocol VPN program, as an academic project from University of Tsukuba, under the Apache License 2.0. The API Suite allows you to easily develop your original SoftEther VPN Server management application to control the VPN Server (e.g. creating users, adding Virtual Hubs, disconnecting a specified VPN sessions) from JavaScript, TypeScript, C# or other languages. SoftEther VPN ("SoftEther" means "Software Ethernet") is one of the world's most powerful and easy-to-use multi-protocol VPN software. It runs on Windows, Linux, Mac, FreeBSD and Solaris. SoftEther VPN is an optimum alternative to OpenVPN and Microsoft's VPN servers. SoftEther VPN has a clone-function of OpenVPN Server. You can integrate from OpenVPN to SoftEther VPN smoothly. SoftEther VPN is faster than OpenVPN. SoftEther VPN also supports Microsoft SSTP VPN for Windows Vista / 7 / 8. No more need to pay expensive charges for Windows Server license for Remote-Access VPN function.
    Downloads: 61 This Week
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  • Veeam Data Platform v13.1 Icon
    Veeam Data Platform v13.1

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  • 5
    OpenH264

    OpenH264

    Open Source H.264 Codec

    Cisco has taken their H.264 implementation and open-sourced it under BSD license terms. Development and maintenance will be overseen by a board from the industry and the open-source community. Furthermore, we have provided a binary form suitable for inclusion in applications across a number of different operating systems and made this binary module available for download from the Internet. We will not pass on our MPEG-LA licensing costs for this module, and based on the current licensing environment, this will effectively make H.264 free for use on supported platforms. OpenH264 is a codec library which supports H.264 encoding and decoding. It is suitable for use in real-time applications such as WebRTC. Constrained Baseline Profile up to Level 5.2 (Max frame size is 36864 macro-blocks). Arbitrary resolution, not constrained to multiples of 16x16. Rate control with adaptive quantization, or constant quantization.
    Downloads: 60 This Week
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  • 6
    Mullvad VPN desktop and mobile app

    Mullvad VPN desktop and mobile app

    The Mullvad VPN client app for desktop and mobile

    In a society that is increasingly determined to weaken that right, a fast, reliable and easy-to-use VPN connection is a good first step towards achieving this. By connecting to the Internet with Mullvad, we ensure that traffic to and from your device is encrypted to the highest standards, even when using public Wi-Fi in a coffee shop or hotel. We do not keep activity logs or ask for personal information, and we even encourage anonymous payments using cash or any of the accepted cryptocurrencies. Your IP address will be replaced with one of ours, ensuring that device activity and location are not linked to your user. Using Mullvad is quick and easy - just download and install the app. Don't spend time on complicated setup and multi-step registration processes. We designed Mullvad to be easy to use. Privacy is essential in a well-functioning society, as it allows norms, ethics and laws to be safely debated and challenged. Without privacy, a free and open society cannot flourish or exist.
    Downloads: 39 This Week
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  • 7
    DAR - Disk ARchive

    DAR - Disk ARchive

    For full, incremental, compressed and encrypted backups or archives

    DAR is a command-line backup and archiving tool that uses selective compression (not compressing already compressed files), strong encryption, may split an archive in different files of given size and provides on-fly hashing, supports differential backup with or without binary delta, ftp and sftp protocols to remote cloud storage Archive internal's catalog, allows very quick restoration even a single file from a huge, eventually sliced, compressed, encrypted archive eventually located on a remote cloud storage, by only reading/fetching the necessary data to perform the operation. Dar saves *all* UNIX inode types, takes care of hard links, sparse files as well as Extended Attributes (MacOS X file forks, Linux ACL, SELinux tags, user attributes) and some Filesystem Specific Attributes (Linux ext2/3/4, Mac OS X HFS+) more details at: http://dar.linux.free.fr/doc/Features.html
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    Downloads: 177 This Week
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  • 8
    Mobile Verification Toolkit

    Mobile Verification Toolkit

    Helps with conducting forensics of mobile devices

    Mobile Verification Toolkit (MVT) is a collection of utilities to simplify and automate the process of gathering forensic traces helpful to identify a potential compromise of Android and iOS devices. It has been developed and released by the Amnesty International Security Lab in July 2021 in the context of the Pegasus project along with a technical forensic methodology and forensic evidence. MVT is a forensic research tool intended for technologists and investigators. Using it requires understanding the basics of forensic analysis and using command-line tools. This is not intended for end-user self-assessment. If you are concerned with the security of your device please seek expert assistance. Compare extracted records to a provided list of malicious indicators in STIX2 format. Generate JSON logs of extracted records, and separate JSON logs of all detected malicious traces.
    Downloads: 29 This Week
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  • 9
    Polarity Browser

    Polarity Browser

    A fast, secure, stable web browser powered by Chromium and Trident.

    Polarity is a dual engine browser powered by both Chromium and Trident that focuses on system efficiency by bringing low RAM and low CPU usage. This browser was also programmed to be optimized for Windows with an Android version available. Browse the web with an uncomplicated UI that is highly customizable with themes, apps, and extensions from the Polarity Store, GreasyFork, OpenUserJS, and UserStyles. Polarity also comes with a built in password manager which safely encrypts all data to prevent theft. Polarity also comes with a built in adblocker and privacy tools such as proxy/VPN support and header masking to prevent further tracking online. If you appreciate all the hard work that we put into creating and developing Polarity, please consider giving a small donation at: https://polaritybrowser.netlify.com/donate
    Downloads: 82 This Week
    Last Update:
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    Cut Data Warehouse Costs by 54%

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  • 10
    Cuckoo Sandbox

    Cuckoo Sandbox

    Cuckoo Sandbox is for automated analysis of malware

    Cuckoo Sandbox uses components to monitor the behavior of malware in a Sandbox environment; isolated from the rest of the system. It offers automated analysis of any malicious file on Windows, Linux, macOS, and Android.
    Downloads: 15 This Week
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  • 11
    Keybase client

    Keybase client

    Keybase Go library, client, service, OS X, iOS, Android, Electron

    Keybase is secure messaging and file-sharing. We use public key cryptography to ensure your messages stay private. Even we can’t read your chats. Keybase works for families, roommates, clubs, and groups of friends, too. Keybase connects to public identities, too. You can connect with communities from Twitter, Reddit, and elsewhere. Don’t live dangerously when it comes to documents. Keybase can store your group’s photos, videos, and documents with end-to-end encryption. You can set a timer on your most sensitive messages. This distribution includes cryptographic software. The country in which you currently reside may have restrictions on the import, possession, use, and/or re-export to another country, of encryption software. BEFORE using any encryption software, please check your country's laws, regulations and policies concerning the import, possession, or use, and re-export of encryption software.
    Downloads: 15 This Week
    Last Update:
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  • 12
    Ente

    Ente

    End-to-end encrypted cloud for photos, videos and 2FA secrets

    Ente is a fully open-source, end‑to‑end encrypted cloud platform designed for securely storing and managing your photos, videos, and 2FA secrets — without needing to trust the service provider. It includes cross‑platform clients and a CLI for self‑hosting needs. Ente is a service that provides a fully open source, end-to-end encrypted platform for you to store your data in the cloud without needing to trust the service provider. On top of this platform, we have built two apps so far: Ente Photos (an alternative to Apple and Google Photos) and Ente Auth (a 2FA alternative to the deprecated Authy). This monorepo contains all our source code - the client apps (iOS / Android / F-Droid / Web / Linux / macOS / Windows) for both the products (and more planned future ones!), and the server that powers them.
    Downloads: 13 This Week
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  • 13
    mhrv-rs

    mhrv-rs

    Rust port of @masterking32's MasterHttpRelayVPN

    mhrv-rs is a Rust implementation of the MasterHttpRelayVPN project designed to bypass DPI-based internet censorship and access blocked websites through HTTP relay techniques. The software works by routing traffic through a user-deployed Google Apps Script relay, allowing requests to evade filtering systems while remaining lightweight and inexpensive to operate. The project emphasizes portability and efficiency by rewriting the original implementation in Rust, improving performance and cross-platform deployment possibilities. It supports desktop and Android environments while providing configurable relay behavior through JSON-based settings and deployment scripts. The architecture is intentionally simple, enabling users to self-host relay infrastructure without relying on centralized VPN services. Overall, MasterHttpRelayVPN-RUST serves as a lightweight censorship circumvention and privacy-focused networking tool.
    Downloads: 11 This Week
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  • 14
    ntfy.sh

    ntfy.sh

    Send push notifications to your phone or desktop using PUT/POST

    ntfy is a simple HTTP-based pub-sub notification service for sending push notifications to phones and desktops. It lets users publish messages to topics using basic HTTP requests, scripts, curl commands, or application integrations. The service can be used through the public ntfy.sh instance or self-hosted on private infrastructure. It is useful for server alerts, cron job results, monitoring notifications, CI/CD updates, and personal automation. ntfy includes web, mobile, and command-line clients, making it accessible across different environments. Its main value is providing lightweight, open-source notifications without forcing users into a heavy messaging platform or paid push service.
    Downloads: 9 This Week
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  • 15
    libsodium

    libsodium

    A modern, portable, easy to use crypto library

    libsodium is a modern, portable, and easy-to-use cryptographic library that serves as an API-compatible fork of NaCl. Consistent behavior and formats across supported platforms. It enhances the original design with build and portability improvements, making it widely deployable across platforms for secure encryption, signatures, hashing, and key derivation. Digital signature creation and verification support. Adds extended cryptographic primitives like BLAKE2 and ChaCha20-Poly1305 beyond NaCl.
    Downloads: 8 This Week
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  • 16
    Brook

    Brook

    Brook is a cross-platform strong encryption and not detectable proxy

    Brook is a cross-platform strong encryption and not detectable proxy. Brook's goal is to keep it simple, stupid and not detectable. You can run commands after entering the command-line interface. Usually, everyone uses the command line interface on Linux servers. Of course, Linux also has desktops that can also run GUI. Of course, macOS and Windows also have command-line interfaces, but you may not use them frequently. Usually, the applications opened by double-clicking/clicking on macOS/Windows/iOS/Android are all GUIs. Usually, if you use Brook, you will need a combination of Server and Client, Of course Brook CLI also has many other independent functions. The Brook CLI file is an independent command file, it can be said that there is no concept of installation, just download this file to your computer, run it after granting it executable permissions in the command line interface.
    Downloads: 7 This Week
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  • 17
    Universal Password Manager

    Universal Password Manager

    Store all your passwords in one secure encrypted database.

    Universal Password Manager allows you to store all your passwords in one highly secure encrypted database. Its strengths are simplicity, portability and security (uses 128bit AES encryption). UPM is available on Android, Windows, OS X & Linux.
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    Downloads: 36 This Week
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  • 18
    DevHub

    DevHub

    Filter issues, activities and notifications

    DevHub is a mobile and desktop app to help you manage GitHub Notifications and stay on top of repository activities. Save custom searches, apply filters and don't miss anything important. Create columns for the repositories and people that matters to you; receive desktop push notifications; manage notifications, issues, pull requests and activities; bookmark things for later. Choose between two modes, desktop or menubar; enable push notifications only for the columns you want. All columns support a common set of filters, like bot, label, issue status, text, etc. The Issues & Pull Requests columns are special: they give you all the power of GitHub Advanced Search on your hands (filter by assignee, number of comments, etc. Create a column for each person and see what they are up to commits, comments, issues, pull requests, tags, releases, etc.
    Downloads: 5 This Week
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  • 19
    Locker Password Manager

    Locker Password Manager

    Open source secure password manager

    Locker is a password manager that goes beyond the mere concept of password management. Whatever your previous password manager provided, we offer even more. Store passwords, passkeys and personal data in one encrypted vault. Manage effectively with categories and folders. Save your passwords with a click, login and checkout made effortlessly with auto-saving and auto-fill features from passwords, payment details to two-factor authentication passcodes. Locker password manager is available anytime on any platform and device, whether it is a web browser, extensions, mobile apps or desktop apps. Share passwords and sensitive data with your friends and colleagues quickly and securely. Or share items with anyone, even if they don't use Locker.
    Downloads: 4 This Week
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  • 20
    Beside

    Beside

    Direct local file, folder & text sharing for Windows & Android.

    Fast. Private. Together. — Send it. It's there. Engineered by Thisma Labs. Beside is a local-first peer sharing app for Windows 10/11 and Android 8.0+. Built with a native Rust core (rustls + ring) and Flutter UI, transfers stay strictly inside your local Wi-Fi at wire speed. Zero cloud, zero accounts, zero tracking. Key Features & Specifications: - Mutual TLS 1.3: End-to-end encrypted with pinned SPKI SHA-256 device keys. - 8-Digit SAS: RFC 8446 TLS Exporter pairing prevents Wi-Fi MITM attacks. - Hardware Keystore: Private keys encrypted in Windows DPAPI & Android Keystore. - Bounded 64 KB RAM: Stream multi-GB files with per-file SHA-256 verification. - OS Integration: System tray, Explorer "Send with Beside", and Android Share Sheet. - Free vs Pro: Free tier included; Pro unlocks unlimited sizes, folders, & Auto-Accept.
    Downloads: 25 This Week
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  • 21
    Smoke Crypto Chat Messenger for Android

    Smoke Crypto Chat Messenger for Android

    Smoke: Android Crypto Chat Messenger

    Smoke is an encrypting chat messenger for Android written in Java. Please read the Web site for more information: https://textbrowser.github.io/smoke/ (original, current) https://www.amazon.com/dp/3752691999/ https://smokeappope.sourceforge.io/ (old, third party archive) Smoke App OPE - Open Personal Encryption Download Android APK Installer: https://sourceforge.net/projects/smokeappope/files/ Smoke Source: https://github.com/textbrowser/smoke SmokeStack Source: https://github.com/textbrowser/smokestack (Android) https://github.com/textbrowser/spot-on (Desktop) Smoke appears to be one of the first projects with an open source mobile encrypting chat server., an decentralized and easily-configurable chat server. Smoke is known as the first mobile McEliece Messenger: https://tarnkappe.info/artikel/english/mceliece-messaging-smoke-crypto-chat-the-first-mobile-mceliece-messenger-published-as-a-stable-prototype-worldwide-279847.html
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    Downloads: 94 This Week
    Last Update:
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  • 22
    BoringSSL

    BoringSSL

    Mirror of BoringSSL

    BoringSSL is a Google-maintained fork of OpenSSL, designed specifically to meet the security, performance, and maintainability needs of Google’s infrastructure and products. While fully open source, BoringSSL is not intended for general public use — it serves as a streamlined, heavily modified SSL/TLS and cryptography library optimized for Google’s internal ecosystem, including Chrome/Chromium, Android, and other Google services. The project prioritizes security, simplicity, and maintainability over backward compatibility. Unlike OpenSSL, BoringSSL provides no guarantee of stable APIs or ABIs, meaning third-party projects depending on it may frequently break. Google products that use BoringSSL ship their own copies and update them as needed, enabling faster iteration without legacy constraints. BoringSSL includes comprehensive API documentation, build instructions, and guidance for porting code from OpenSSL.
    Downloads: 3 This Week
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  • 23
    Tamper Dev

    Tamper Dev

    Extension that allows you to intercept and edit HTTP/HTTPS requests

    If you are a developer, you can use Tamper Dev to debug your websites, or if you are a pentester, you can use it to search for security vulnerabilities by inspecting the HTTP traffic from your browser. Unlike most other extensions, Tamper Dev allows you to intercept, inspect and modify the requests before they are sent to the server. This extension provides functionality similar to Burp Proxy, MITM Proxy, OWASP ZAP, Tamper Data, and Postman Proxy, but without the need of additional software, with full support of HTTPS connections, and trivial to set-up (just install).
    Downloads: 3 This Week
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  • 24

    PyLoris

    A protocol agnostic application layer denial of service attack.

    PyLoris is a scriptable tool for testing a server's vulnerability to connection exhaustion denial of service (DoS) attacks. PyLoris can utilize SOCKS proxies and SSL connections, and can target protocols such as HTTP, FTP, SMTP, IMAP, and Telnet.
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    Downloads: 19 This Week
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  • 25
    AuthPass.app

    AuthPass.app

    Password Manager based on Flutter for all platforms

    Password Manager based on Flutter for all platforms. Keepass 2.x (kdbx 3.x) compatible. Load/Decrypt kdbx using password and/or key file. Search through stored credentials. Organize passwords using groups. Desktop (Mac, Linux, Windows): Keyboard shortcuts for Search, Copy, Navigation, etc. Desktop & Mobile: Copy & paste support. Store master password in the KeyStore/KeyChain secured with biometric data. (Fingerprint, Face Unlock, etc.) Hook into native APIs for seamless integration into Form-Fills. (Only available on Android right now) Easily keep your passwords synchronized between all your mobile and desktop devices. Using Google Drive, Dropbox or WebDAV (NextCloud, OwnCloud, etc.)
    Downloads: 2 This Week
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