printsim

3D print simulator

The fanciest loading bar for your 3D prints.

Load the file you're printing, hit start when your printer does, and watch it build layer by layer from anywhere.

Runs entirely in your browser. Your file stays on this device, unless you send it to your phone (encrypted, gone after 2 hours).

New here? Here's the deal

Lab printers like the Prusa MINI+ aren't on the network, so once you hit print, the only way to check on it is to walk back. printsim is a stand-in: give it the same file you gave the printer, tap Start when the printer starts, and it rebuilds the print in 3D in real time, with how long is left and when it'll be done.

  • Live 3D buildThe printer moves and the layers stack up as they print, from your dorm or class.
  • Timelapse firstScrub or play the whole print at up to 1000× before you commit an 8 hour print.
  • Spaghetti checkForgot supports? It flags what'll droop or fall, and shows it happening.
  • Close the tab, it's fineIt remembers the print. Come back later and it picks up where the printer should be.
  1. Load the same file you sent to the printer
  2. Start the sim the moment you press print
  3. Resync any time by typing the % on the printer's screen

Tuned for the Prusa MINI / MINI+ using Prusa's own firmware numbers. Other printers get a generic profile. Timing is an estimate, not a live feed.

What does the printer show?

The sim jumps to exactly that point in the file. Do this right before you walk away from the printer.

Or type it in:

%
Time left on its screen (more precise)

When did it finish?

This is how printsim learns how fast this printer really is. Rough is fine.

Name this printer

Something you'll recognise at the lab. Each named printer learns its own speed.

Your prints

Running more than one printer? Each print gets its own page, so you can follow them all from here.

In the works

What's being built and fixed next. Still Prusa MINI+ first.

Up next

  • Scanner trained on real screens"Scan the printer screen" learned on simulated photos. Real photos of the lab MINIs come next, so it reads more of them first try.
  • TimingOn some prints the sim trails the printer by 1 to 2%. Real timing runs at the Brandeis lab are tuning it.

Getting better

  • More materialsPLA overhangs and bridges are tuned from a real test print. PETG and PLA with the fan off are next.
  • Topple and warp limitsThe new warnings use OrcaSlicer's brim rule, which was tuned on other printers. A tall, thin test print on the MINI+ will check it.

Maybe later

  • Heads-up alertsA ping a few minutes before the finish or a filament change.
  • More printersMK4, Core One and .gcode.3mf files, once the MINI+ is nailed.

Updated 16 Oct 2026

Get pinged when it's done

Adds calendar events with alerts, so your phone buzzes even with printsim closed.

Google Calendar

Your timelapse

Save video

Continue on your phone

Scan this with your phone's camera. printsim opens there and carries on right where this print is, file and all.

Pick up the print here

Share progress

A link with a live countdown to the finish. Your friend needs no app and no file. It's a snapshot of the plan right now: if you pause or resync, the old link drifts, so share again.

This print isn't tracked here