14 Best Open Source Applications for Windows (2026)
Which are the best open source applications for Windows in 2026? Open source software is built in public: anyone can read the code, check what it does and improve it, and the programs are free to use. Many of the apps people run every day on Windows 11 are open source without them even realising it. Here is our updated list of 14 open source apps that are actively maintained and worth installing today.
Quick answer: The best open source applications for Windows are Firefox (browser), Thunderbird (email), LibreOffice (office suite), GIMP and Inkscape (graphics), VLC (media player), Audacity (audio), OBS Studio (recording), HandBrake (video converter), 7-Zip (archives), KeePassXC (passwords), qBittorrent (torrents), FileZilla (FTP) and Python (programming).
Table of Contents
Why use open source applications on Windows?
- Free for good: no trial periods or subscriptions for the core program.
- Transparent: the source code is public, so security researchers and users can see what the software does.
- Long lived: popular projects are kept going by communities and foundations, not one company’s plans.
- Open file formats: your documents are not locked into one vendor.
Open source is not the same as simply free: some free programs (freeware) keep their code closed. If you just want free replacements for paid or built-in Windows tools, see our list of free Windows software alternatives.
The 14 best open source applications for Windows
1. Mozilla Firefox (web browser)
Firefox (external site) is the best-known open source browser and the main browser not built on Google’s Chromium engine. It has strong privacy protections, add-ons and sync across devices. A bit of history from our original 2009 article: Firefox 3 set a Guinness World Record in June 2008 for the most software downloads in 24 hours, with over 8 million downloads.
2. Mozilla Thunderbird (email client)
Thunderbird (external site) is a desktop email client with a spam filter, calendar, multiple accounts and add-ons. It is a good free replacement for Outlook for personal email accounts.
3. LibreOffice (office suite)
LibreOffice (external site) includes Writer, Calc, Impress, Draw and Base, and opens and saves Word, Excel and PowerPoint files. It grew out of OpenOffice.org, the open source office suite in our original list, and is the actively developed choice today.
4. GIMP (photo editor)
GIMP (external site), the GNU Image Manipulation Program, is a full image editor with layers, masks, filters and plugins. It can also open Photoshop PSD files, which makes it the best-known open source alternative to Photoshop.
5. Inkscape (vector graphics)
Inkscape (external site) is a vector drawing program for logos, icons, diagrams and print designs, working natively with SVG files.
6. VLC Media Player (audio and video)
VLC (external site) plays almost any audio or video format without extra codec packs, plus DVDs, audio CDs and network streams. It is cross-platform and can also convert files and record streams.
7. Audacity (audio editor)
Audacity (external site) records and edits audio: trim podcasts, remove noise, change speed and export to common formats.
8. OBS Studio (screen recording and streaming)
OBS Studio (external site) records your screen, webcam and microphone and streams live to platforms such as YouTube and Twitch. It is widely used by streamers and for tutorial videos.
9. HandBrake (video converter)
HandBrake (external site) converts and shrinks video files with ready-made presets for phones, tablets and the web, and can process a queue of files in one go. It replaces MediaCoder from our original list, which is no longer an open source project.
10. 7-Zip (file archiver)
7-Zip (external site) opens ZIP, RAR, 7z, TAR and many other archive formats, and its own 7z format compresses very well. It adds handy options to the File Explorer right-click menu.
11. KeePassXC (password manager)
KeePassXC (external site) keeps your passwords in an encrypted database file on your own computer, with no account or cloud needed. Prefer syncing across devices? Bitwarden is another open source option.
12. qBittorrent (BitTorrent client)
qBittorrent (external site) is an ad-free open source torrent client with a built-in search engine and RSS downloader. Note that uTorrent, named in our original article, is not actually open source; qBittorrent is the open alternative. Only download files you have the right to share.
13. FileZilla (FTP client)
FileZilla (external site) is a full-featured FTP, FTPS and SFTP client for uploading files to web servers. Download it from the official site and untick any extra offers during installation.
14. Python (programming language)
Python (external site) is one of the most popular programming languages for beginners, automation, data analysis, AI and web development (with frameworks such as Django). Install it on Windows from python.org or the Microsoft Store.
More open source apps worth a look
- Notepad++ (external site): a fast text and code editor.
- ShareX (external site): screenshots, screen recording and annotations.
- Microsoft PowerToys (external site): Microsoft’s own open source extras for Windows, such as window layouts and bulk renaming.
How to install open source apps safely
- Download from the project’s official website or the Microsoft Store, never from download portals that wrap installers with ads.
- Use WinGet, the Windows package manager, to install and update many of these apps from the command line.
- Keep apps updated: open source projects fix security issues quickly, but only if you install the updates.
FAQ
What is an open source application?
An app whose source code is published under an open source licence, so anyone can use, study, change and share it.
Are open source applications safe for Windows?
Well-known, actively maintained projects downloaded from their official sites are safe to use. Avoid unofficial download sites.
Is open source the same as free software?
Not exactly. Open source apps are almost always free, but many free apps (freeware) keep their code closed.
What is the best open source alternative to Microsoft Office?
LibreOffice is the most complete open source office suite for Windows.
Originally written by guest author Abhimanyu, owner of MWolk Media and a full-time blogger. Updated for 2026 by QuickOnlineTips.
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Handbrake should be included in your list. it is a great DVD ripping and conversion freeware.
ckick to start and open to application for window
Great listing I ever saw at any tech blog and that’s why it’s eligible for thanksgiving from heart.
It’s your discovery, good job!
Most of the open source applications don’t work well and unstable. It’s a waste of time downloading them.
mando says:
September 8, 2009 at 9:27 pm
Most of the open source applications don’t work well and unstable. It’s a waste of time downloading them.
LOL. I have never had so many problems with Windows and it’s over-priced OS. You probably just don’t know how to install the software and you call tech support for every little thing. I work tech-support for a major company and the people who ALWAYS call in say things like that. Stick to your proprietary software and continue to have your hand held for you. The FOSS don’t need ya! ;)
clamwin is cool. even cooler if they can FINALLY add that real time scan capability.
Clamwin’s detection rate is atrociously bad on windows.
uTorrent is closed-source freeware.
Firefox and Vic media player are my favorites in above list.