3MF to STL on Mac and Linux — no install
No app, no Homebrew formula, no permission dialog. Open a browser on macOS, Linux or ChromeOS, drop the 3MF in, and take the STL away.
Drop .3mf files here
or drag & drop — up to 150 MB each, multiple files supported
Why a browser is the right place for this
Converting 3MF to STL is a ZIP unzip plus some arithmetic — the kind of job that needs no disk access and no GPU. Running it in the page means the model never leaves your machine, there is nothing to update, and the same workflow works on a 2015 MacBook and a brand-new M-series laptop.
macOS: two steps, then Finder
- Open the converter in Safari, Chrome or Edge — any current browser works.
- Choose the .3mf or drag it onto the drop area. Conversion starts immediately.
- Click Download STL. The file lands in your Downloads folder unless you changed the browser default.
Keyboard note: ⌘ is not involved anywhere. The converter is pure pointer and click, so it also works on an iPad with a trackpad.
Linux and ChromeOS
Identical behaviour. Firefox, Chromium and Chrome all run the converter, and because no upload endpoint is contacted, a corporate network or an offline machine behaves the same as a home one.
iPad, iPhone and the 150 MB ceiling
The page is responsive and runs on mobile Safari. Phones have less memory than laptops, so the 150 MB per-file limit bites harder there — split large assemblies on a desktop, or convert the pieces one at a time.
Tip: if the download does not appear, check the browser is allowed to download from this site. A strict popup blocker can suppress the save — allow pop-ups for the page and it will come back.
Still working in a slicer afterwards?
The same flat STL feeds Cura, PrusaSlicer and Bambu Lab, and the format decision is unchanged. For everything that goes wrong, the troubleshooting hub has the fixes.
Frequently asked
Do I need to install anything on macOS?
No. Open the converter in any current browser and drop the file in. Nothing is installed, no Homebrew, no permission prompts.
Can I convert 3MF to STL on an iPad?
Yes — the layout is responsive and runs in mobile Safari. Phones have less memory, so the 150 MB cap is the practical limit there.
Where does the STL land on a Mac?
Your browser download folder — Downloads in Finder unless you changed the default. The Download STL button triggers it deliberately.
Is Linux different?
No. Firefox, Chromium and Chrome all run it the same way, and because nothing is uploaded, offline machines behave identically.