Explorer, minus the waiting.
A file manager for Windows built around one rule: the UI never blocks. Tabs, a launcher, previews for almost anything, folders that remember how you like them, and its own copy engine.
Every millisecond is on a budget.
Anything that takes more than a few milliseconds runs on a worker thread and the UI draws what it already has. These are real timings from the beta changelog. The F12 overlay shows the same numbers on your own machine.
Measured on the developer's machine during the beta. Your numbers will depend on your disk and CPU.
Press Enter. It's already there.
Images, video, comics and huge text files open in MagnumOpus View, a viewer of its own. It waits in the background and decodes the file you're on before you ask, so opening is just showing. Neighbouring images are prepared too, so the arrow keys switch instantly.
Correct colors from embedded profiles, HDR mapped to normal brightness, gigantic images shown without loading them whole. The next images in the folder are prepared ahead, so the arrow keys switch instantly.
FFmpeg inside, so every format plays. Audio tracks, subtitles, a thumbnail when you hover the seek bar, and it remembers where you stopped.
Logs, CSV and JSON of tens of gigabytes open almost instantly: the viewer reads only what is on screen and indexes the rest in the background. Line numbers, search, go to line and follow the end of a log. A 64 MB single-line JSON scrolls without delay.
Edit and save even multi-gigabyte files: the file is never copied into memory and saving streams in the background. Change or convert the encoding too.
A comic opens like a book: arrows turn pages, D for a two-page spread, W to fit the width and scroll, M for manga read right to left. Every comic remembers its own modes and continues on the last page.
In the explorer the file thumbnail shows the cover (6-7 ms) and the preview pane pages through the comic like a PDF. Have your own reader? Turn it off in Settings.
How we measured: each app launched with the file, a 60 fps screen recording, time until the window shows the content and stops changing. Median of 3 runs, same files and the same PC for every app (Windows 11, files in the disk cache).
Built for people who live in their files.
Ideas borrowed from the tools power users already love: File Pilot's launcher, Everything's name index, Total Commander's keyboard flow, Directory Opus's folder formats, VS Code's tabs and command palette.
Folders that remember
Templates set view, sorting, grouping and columns per folder type: photos in a grid, code in details. Lock any folder with Ctrl+K and it opens exactly the same way every time.
Find it before you finish typing
Ctrl+P opens a launcher for recent places, bookmarks and drives, with a calculator built in. Search across the whole PC through a name index. Filter any folder with a small query language:
[ext = pdf] [size > 10mb] [modified > today]Preview almost anything
Images, code with syntax highlighting, hex, PDF, video, Office documents, EXIF and .NET assemblies. Minified JSON, XML and CSS are formatted for reading and you can search inside the preview.
Copying you can trust
Copy and move run in their own process with real progress, conflict handling, verification, elevation when needed and undo. If the explorer window closes, the copy keeps going.
Servers as folders
Browse SFTP, FTP and FTPS next to your local drives, with the same list, preview and copy engine. A virtual Apps folder lists everything from the Start menu.
At home in Windows
Shell context menu (7-Zip, WinRAR, Open with), drag and drop to any app, "Show in folder" from browsers and torrent clients, multiple windows, per-monitor DPI, light and dark themes. It can replace Explorer, and put it back.
Your hands stay on the keys.
Every shortcut can be remapped. Pick the Explorer profile or the Total Commander profile and adjust from there.
Try the beta.
MagnumOpus is in public beta. It's free while it's in beta, and your bug reports decide what gets fixed first.
Download
Download for WindowsInstaller · 0.1.0-beta.6- Installer: per user, no admin rights needed
- Portable ZIP: unpack anywhere and run
- Windows 10 1809+ or Windows 11, 64-bit
Beta builds aren't code-signed yet, so Windows SmartScreen may warn about an unknown publisher. Choose "More info" and then "Run anyway".
Help shape it
MagnumOpus is built by one developer in the Czech Republic, in the evenings. If it saves you time, a coffee keeps it going.
Buy me a coffeeon Ko-fi · voluntary, everything works without it- Report bugs and ideas on GitHub Issues
- Tell a friend who still fights with Explorer