OrcaSlicer 2.5.0 is now a stable release. The official v2.5.0 release notes on GitHub, published November 7, 2026, call it "the biggest update in OrcaSlicer's history, built from nearly 1,300 pull requests by more than 180 contributors." It follows a release candidate that went out November 1. The headline additions are a plugin system, color mixing from loaded filaments and an experimental parametric Design tab. Before you click update, though, read the upgrade notes: two of them change default behavior, and you may not notice the difference until a print comes off the bed looking wrong.
Plugins arrive, with a permissions tab and a warning
The largest structural change is a Plugins window. Plugins, which the release notes describe as Python plugins, are subscribed to through an Orca Cloud account. A new Permissions tab in that window shows what each plugin is allowed to do, grouped into four categories: File system, Network access, Execution and Audit events. That puts the scope of a plugin in front of you before you rely on it, the way permission prompts work on a phone.
The project is direct about the limits of that model. "They aren't a sandbox, so install plugins you trust," the release notes say, and they add that permissions guard against mistakes, not against a malicious plugin. The permission tab tells you what a plugin is allowed to do. It does not fully isolate a plugin from your files or network. The sensible approach is the one you would take with any third-party code running on a machine that also holds your printer credentials and network access: install few plugins, prefer known authors, and pay attention to anything that asks for network access or execution rights without an obvious reason.
Color mixing, a Design tab and smarter bed layout
Color mixing lets OrcaSlicer blend new colors from the filaments already loaded, which should widen the palette on a multi-material setup without adding spools. The Design tab, still marked experimental, lets you design parametric parts inside the slicer. For simple brackets, spacers and test pieces it may save a trip to a separate CAD program, though that is our expectation rather than a claim from the project.
Less flashy but probably more useful day to day: toolhead collision volumes keep Arrange, brims and travel moves clear of bed clips and tool docks. The release also says OrcaSlicer starts, slices and exports noticeably faster, and adds support for mixed nozzle sizes on Bambu Lab's H2D and X2D.
The release candidate already carried several other features that were in the alpha, according to Makers101's coverage of the RC: belt printer support and Texture Displacement among them. The RC brought Bambu's H2C and A2L support, first added in the alpha, to a near-final build, with per-hotend filament tracking on the H2C's nozzle rack, and fixed nozzle assignment in Filament-Saving Mode. Qidi Box owners gained slot selection on models such as the X-Plus 4, Q2, Q2C, X-Max 4 and X-Plus 5. That requires enabling "Use printer agents instead of print hosts" under Preferences > Developer, and the Calibration tab is hidden for Qidi printers. Moonraker users got a fix for a print dialog that hung at "Synchronizing device information...".
Two upgrade notes that change your prints
These two items need your attention before you start production work on 2.5.0.
Bambu Lab process presets now default to Grid infill. They previously used Cross Hatch. If you print from stock Bambu presets and never set infill yourself, your parts will get a different internal structure after upgrading, and so will parts from your own presets based on them. For most decorative prints that won't matter. For functional parts whose stiffness, weight or print time you tuned on the old pattern, it may. To keep Cross Hatch, set it explicitly in your process preset, or re-check those parts on the new default.
Features left on "Default" now always use the object's own filament. In Filament for Features, a feature left at Default will print with the filament assigned to the object. Before, choosing a filament for infill or a top or bottom surface could quietly switch other Default features to it as well. If an older project relied on that, colors or materials may land somewhere you didn't expect. Makers101 made the same point at the RC stage: check your multi-filament projects. Open them, preview them slice by slice, and set assignments explicitly where it matters.
What changed between the RC and the final
The six days between the RC and the stable build were mostly fixes, and several of them affect print quality directly:
- Bridges now print at bridge speed when "Slow down for curled perimeters" is enabled.
- Scarf joint banding with the Arachne wall generator and arc fitting together has been fixed.
- Klipper printers no longer stop over the wipe tower at tool changes.
- Crashes involving Mesh Boolean and filament sync are resolved.
- Gap fill now prints after the lines around it in order-keeping fills such as Monotonic and Concentric.
- Cleaner infill paths for Adaptive density, TPMS-FK and Optimized Gyroid saved 2 to 6 minutes on 2 to 4 hour prints in the author's test project. Plain Gyroid is unchanged.
- On belt printers, the brim was previously laid lower above the belt than the part's outer wall, by 0.12 mm at 45 degrees with 0.32 mm layers; brim and part now sit at the same height. The notes advise re-leveling your belt if you leveled it against the brim.
The Klipper wipe tower fix is the one most likely to have caused visible defects. According to the notes, extra stops over the tower, up to five per tool change, let the nozzle ooze onto it, and on one print with 247 tool changes they cost about 30 minutes. The bug dates to the 2.5.0 alpha, so if you saw it on an earlier build, this one should take care of it.
Installers are available for Windows on x64 and arm64, for macOS, as a Linux AppImage and as a flatpak.
What It Means for Makers
For most users, 2.5.0 is worth installing. The obstacle-aware Arrange and travel changes, the bridge and scarf seam fixes and the Klipper tool-change fix are practical improvements, the kind that prevent failed prints rather than add options to menus. Owners of Bambu's newer multi-nozzle machines and Qidi Box users get support that simply wasn't there before.
Be careful about how you upgrade. Back up your profiles first. Re-slice one known-good functional part and one multi-filament project, and compare the previews against your last good output before you trust the new build with long jobs. Pay particular attention to infill pattern on Bambu presets and to filament assignments on anything that uses Default.
Treat plugins as the newest and least proven part of this release. The permission tab is a real improvement in transparency, but the project says plainly that it is not a sandbox. Wait to see which plugins the community vets before installing them on the machine that drives your printers. For an open-source slicer, that is how plugins should be handled anyway.
The Design tab is still experimental. It may be useful for quick jigs, but keep your real CAD workflow for now.
