Snapmaker U1 .3mf converters, compared
Several tools convert multicolor files for the Snapmaker U1 — including one from Snapmaker themselves. I build one of them, so treat this as informed rather than neutral: every claim below comes from the other tools' own pages and is linked, so you can check it.
Last checked: 17 August 2026. These tools ship changes; if something here is out of date, tell me and I'll fix it.
First: Snapmaker has its own converter, and it's free
Snapmaker publishes a U1 3MF Converter guide covering Bambu Studio and MakerWorld files, keeping your print settings, with up to 4 filaments per plate. If that covers your file, use it — it's from the people who make the printer, and nothing on this page beats “official and free” for a straightforward conversion.
The tools below exist for what falls outside that: sources other than Bambu and MakerWorld, more than 4 colors, batch work, STL, or retargeting a U1 file to another printer.
Does your file leave your computer?
BedReady, U1 Forge and the 3mf-to-u1 extension all convert inside your browser. bl2u1 uploads your file to a server and, per its own page, keeps it there for 8 hours. That's fine for a free MakerWorld model. It is not fine for a paid model, a client's file, or anything you don't have redistribution rights to.
“In your browser” has stopped being one thing, though. bambu2orca is billed as a zero-upload converter, and its geometry really does stay local — its own FAQ says so, and invites you to check in DevTools. What it posts to its API is the project's settings, its object names and their bounding boxes. No mesh, but not nothing.
So the honest version of my own claim is the specific one, not the adjective: BedReady sends no part of your file anywhere — not the model, not its settings, not even the file name. The one exception is labelled where it happens: for files too large for a browser tab there's an optional server converter, and it's a button you press, never something that happens on its own.
| BedReady | bl2u1 | U1 Forge | bambu2orca | |
|---|---|---|---|---|
| Source files | Bambu, Prusa, Creality, Orca | Bambu Lab only | Bambu, Prusa, MakerWorld | Bambu Studio only |
| Where conversion runsbl2u1's own page states uploaded files are deleted from the server after 8 hours. bambu2orca keeps your geometry local and posts the project's settings and object names to its own API — see the section above. | Your browser | Their server | Your browser | Your browser, but settings are sent to their server |
| Price | Free | Free (donations) | First export free, then ~$2 each | Free |
| Daily limitA converter that runs entirely on your own machine has nothing to meter. One that calls an API has to. | None | Not documented | Not documented | 35 conversions per 24 hours; 150 on the Ko-fi supporter tier |
| Keeps painted multicolor | Yes | Yes | Yes | Yes |
| More than 4 colorsThe U1 has 4 physical slots, so every tool has to do something here — the question is what. | Full Spectrum mixing, M600 swap pauses, or band-swap | Pick 4, the rest are dropped | Not documented | All slots passed through; you map them in Orca |
| U1 nozzle profilesThe one row on this page where somebody beats me outright. If you print with a 0.2 or 0.6 nozzle, that matters — it's on my list. | 0.4 | Not documented | Not documented | 0.2, 0.4, 0.6, 0.8 |
| Retarget to other printers | U1 → Bambu / Prusa / Creality | No | No | No |
| STL ⇄ 3MF | Yes | No | Not documented | No |
| Batch convert a folder | Yes | No | Not documented | Ko-fi supporter tier only |
| Live colored 3D preview | Yes, before you download | No | Not documented | Not documented |
| Installs Orca filament profiles | Yes | No | No | No — but it relabels presets to Generic or Snapmaker |
| Browser extension | Chrome + Firefox | Separate extension exists | No | No |
| Desktop app | macOS, Windows, Linux | No | No | No |
| Languages | 7 | English | English | English |
When to use one of the others instead
- U1 Forge has modes BedReady doesn't: painting color regions in the browser, applying surface textures, and cutting models. If you want to author color rather than convert someone else's file, it does things I don't.
- bl2u1 is open source (GPL-3.0) and self-hostable — as is BedReady, at github.com/BedReady/bedready. If you want to run the conversion on your own infrastructure, or read exactly what it does to your file, that's a real advantage.
- Snapmaker's own converter is official and free. For a straightforward Bambu or MakerWorld file inside 4 filaments, that is the obvious first stop.
- bambu2orca ships U1 profiles for 0.2, 0.4, 0.6 and 0.8 nozzles and picks one to match your file's layer height. I only ship 0.4. If you print with a different nozzle, use it — that is a real gap on my side and no amount of the rest of this table closes it. It also carries every filament slot through untouched rather than fitting them to the U1's 4 heads, which is what you want if you'd rather do the mapping yourself in Orca.
- 3mf-to-u1 is a Chrome and Firefox extension that catches .3mf downloads from any site and converts them before they hit your disk, entirely locally. If a browser extension is all you want, it does that job and it's open source (GPL-3.0).
- Full Spectrum color mixing is no longer something only I do. Snapmaker Orca has 2–3 color mixing natively, and there are community tools — fullspectrum-helper, u1hub — that plan mixes too. Mine does more (arbitrary painted colors mapped onto 4 heads, a custom CMYK basis, per-color overrides), but “we do Full Spectrum” on its own is no longer a reason to pick this over those.
- Snapmaker Orca itself keeps improving. If your file is already a U1 or Orca project, you very likely don't need any converter — open it directly.
Try it on a file that's given you trouble
Nothing uploads, there's no account, and you see the colors before you download. If it gets your file wrong, send it to me — that's the most useful thing anyone can do.
Sources: bl2u1.nbn.cat, josuanbn/bl2u1, U1 Forge announcement, Snapmaker U1 3MF Converter guide, ericreid/3mf-to-u1, bambu2orca (its landing page and FAQ, read 17 August 2026). BedReady is an independent project and is not affiliated with Snapmaker, Bambu Lab, or the authors of the tools above. “Not documented” means the tool's public page doesn't mention the feature — not that it definitely lacks it.