How to 3D print from an iPad

What an iPad can and cannot do for 3D printing

A 3D printer does not print an STL. It prints G-code, the list of moves and temperatures a slicer writes for one particular machine. The slicers most people use (OrcaSlicer, PrusaSlicer, Cura and Bambu Studio) are desktop programs for Windows, macOS and Linux, and none of them has an iPad version. An iPad with an M-series chip does not run Mac apps either, so installing your usual slicer is not an option.

That leaves three routes on an iPad:

1. A slicing app from the App Store. A few exist. Check that it has a profile for your exact printer; a profile borrowed from another machine brings the wrong bed size and start sequence.
2. The printer maker's app. Some makers have an app that starts prints on their own printers, and some of those print models from the maker's own model site. What they can do with a file from your iPad varies by app and version.
3. A slicer in the browser. The slicing runs on a server, and Safari shows the model and the settings. This is the route this article follows, with SpeakCAD's online slicer.

Step 1: get the model onto the iPad

The slicer takes an STL or a 3MF of up to 50 MB. Download it in Safari from Printables, MakerWorld or Thingiverse, and it lands in the Files app, in the Downloads folder (in iCloud Drive or on the iPad, depending on Safari's download setting). A model that arrived by e-mail or message goes to Files through Share, then Save to Files. A model on a USB stick can stay there: the stick appears in Files under Locations.

Step 2: slice it in Safari

1. Open the online slicer in Safari and sign in, or create an account (free, no card).
2. Tap Choose a file. Depending on the iPadOS version, you see the Files browser directly or a short menu first, with the photo library, the camera and an option to browse files. Pick the model.
3. The model opens in 3D. Turn it with a finger and check that it is the part you meant, at a plausible size. An STL carries no unit, so a model exported in inches arrives 25.4 times too small; fix that where the file came from.
4. Choose your printer's Brand, Model and Nozzle among 380+ printers from 60+ brands. It is saved on your account for next time.
5. Pick the Print profile (the layer height) and the Material that is loaded. Leave Supports and Adhesion on Auto for a first print.
6. Tap Slice and download.

The slicing is done by the unmodified OrcaSlicer with the profile of the printer you picked. With the file you get the estimated print time, the filament in grams and meters, the layer count and whether supports were added. To compare a setting, change it and slice again: re-slicing the same file within 10 minutes spends nothing.

Step 3: find the G-code

Safari saves the G-code to the same Downloads folder in Files, and the download arrow in Safari's toolbar lists it. Most printers get a .gcode file; Bambu Lab printers get a .gcode.3mf. If Safari changed the name or dropped part of the extension, touch and hold the file in Files and rename it. The contents do not change, but the printer's screen may not list a file without the right ending.

Step 4: send it to the printer

SD card or USB stick

This works with nearly every printer, connected to a network or not.

• iPads with USB-C take a USB-C card reader or a USB-C stick directly.
• iPads with a Lightning port need an adapter, such as Apple's Lightning to SD card reader.

The card shows up under Locations in Files. Copy the G-code from Downloads onto it, wait for the copy to finish, then put the card in the printer and choose the file on its screen. Short, plain file names are easier to find on a small printer screen.

The printer's web interface

Many printers have a page on the local network where you upload a file and start a print. Klipper printers usually run Mainsail or Fluidd; OctoPrint runs on a small computer, often a Raspberry Pi, connected to the printer; networked Prusa printers have PrusaLink. All are web pages, so they work in Safari:

1. Find the printer's IP address on its screen (usually in the network settings) or in your router.
2. Type it into Safari's address bar, on the same Wi-Fi as the printer.
3. Tap the upload button, choose the G-code in the Files browser, and start the print.

Prusa printers connected to Prusa Connect can also take the upload from Prusa's web dashboard in Safari.

Bambu Lab printers

The microSD card always works: copy the .gcode.3mf to it through a card reader and start it from the printer's screen. Bambu Handy, Bambu Lab's app, monitors prints and starts them; whether it can send a file from your iPad's storage depends on the app version, so check it once in the app. The .gcode.3mf explained covers the Bambu routes in detail.

What the iPad route will not do

The online slicer covers single-material prints with the settings that shape a part: layer height, filament, infill, walls, supports, speed, adhesion and orientation. It does not do multi-colour painting, modifiers, variable layer height, custom start G-code or a layer-by-layer preview of the toolpaths. A print that needs those needs a desktop slicer on a computer. Online slicer vs desktop slicer sets out where each one wins.

What it costs

The online slicer gives every account 1 free slice, its first (a free account, no card). After that, a slice uses one slice from a Slicer pack (20 slices for $3, once, never expire) or 5 credits, and slicing is included in Pro and Unlimited. Re-slicing the same file with other settings within 10 minutes is free. On every plan, an account can start up to 60 slices a day. To estimate a print's time, filament and cost before slicing it, the print time and cost calculator works without an account.

The short version

Save the model to Files, slice it in Safari, then copy the G-code to the printer's card or upload it on the printer's web page. Slicer for iPad keeps the steps and the usual questions on one page, and the online slicer is ready for the file you have.