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; PaintPort added 1 October 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 These tools ship changes; if something here is out of date, tell me and I'll fix it.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, PaintPort 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 | PaintPort | |
|---|---|---|---|---|---|
| Source files | Bambu, Prusa, Creality, Orca | Bambu Lab only | Bambu, Prusa, MakerWorld | Bambu Studio only | Bambu, MakerWorld, Orca, PrusaSlicer (painted 3MF) |
| 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 | Your browser, or offline as one HTML file |
| Price | Free | Free (donations) | First export free, then ~$2 each | Free | Free (AGPL-3.0) |
| 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 | None stated; runs locally |
| Keeps painted multicolor | Yes | 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 | Maps to the spools you have loaded by color distance; the rest as ColorMix blends |
| U1 nozzle profilesOnly my 0.4 profile is a real export from a U1 that has printed; the other three scale it by nozzle ratio, and the converter says so when you pick one. bambu2orca ships a preset for each size. | 0.4 tested; 0.2, 0.6 and 0.8 derived from it, and labeled as derived | Not documented | Not documented | 0.2, 0.4, 0.6, 0.8 | Not applicable: it remaps paint and blends, not printer profiles |
| Retarget to other printers | U1 → Bambu / Prusa / Creality; Bambu or Orca → a Prusa CORE One INDX (8T or 4T) project | No | No | No | Painted 3MF → Prusa Core One INDX, Bambu Studio or Snapmaker Orca |
| STL ⇄ 3MF | Yes | No | Not documented | No | No: painted 3MF only |
| Batch convert a folder | Yes | No | Not documented | Ko-fi supporter tier only | Not documented |
| Live colored 3D preview | Yes, before you download | No | Not documented | Not documented | Yes, original against mapped |
| Installs Orca filament profiles | Yes | No | No | No — but it relabels presets to Generic or Snapmaker | No |
| Browser extension | Chrome + Firefox | Separate extension exists | No | No | No |
| Desktop app | macOS, Windows, Linux | No | No | No | No, but the single HTML file works offline |
| Languages | 7 | English | English | English | English, German |
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 offer the same four, but only my 0.4 is a real export from a machine that has printed; the others are derived from it. If you print with a different nozzle and want a profile nobody had to derive, that is a fair reason to use 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.
- PaintPort starts from the spools you actually have loaded: you enter the color in each slot (or pick a CMY, CMYK or CMYKW preset) and it matches every painted color to the closest one, blending the ones with no close match. If your colors are set and the file has to fit them, that is the better question to start from. Both tools now turn a Bambu or Orca file into a Prusa CORE One INDX project with the colors on the right tools and ColorMix blends for the ones no spool matches. PaintPort also writes Bambu Studio's mixing format, so if you blend on a Bambu printer, use it. What it does not do is supply the target printer's profile: its README notes that opening the result as a project can put placeholder presets in place of yours. It is open source (AGPL-3.0), and the whole tool is one HTML file that runs offline.
- 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), PaintPort and perspektive3d/paintport (its page, README and changelog, read 1 October 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.