G-code
G-code viewer
See exactly what your printer will do: every layer, line and travel move, with print time and filament.
- Nothing uploaded
- No sign-up
- Free, no limits
Drop your G-code here
or paste it, or pick it from your device
.gcode · .gco · .g · .bgcode · .3mf
- Drop your G-code file
- Step through the layers
- Check time and filament
Good to know
How to check a G-code file
- Drop a .gcode, .bgcode or sliced .gcode.3mf file above.
- Drag the Layer slider to step through the print, and Moves in this layer to watch the nozzle draw it line by line. The G-code lines for that move are shown underneath.
- Colour the lines by feature type, speed, volumetric flow, fan, temperature or layer time, and untick features to hide them.
Your files stay on your device; nothing is uploaded, and the viewer works offline once loaded.
What it reads
- PrusaSlicer, Bambu Studio, OrcaSlicer, Cura and Simplify3D G-code, with their feature names mapped to one legend (outer wall, inner wall, infill, support, bridge and so on).
- Binary G-code (.bgcode), which PrusaSlicer writes for the MK4, MK3.9, XL and MINI by default. It's decoded right in your browser, thumbnails included.
- Sliced 3MF (.gcode.3mf) from Bambu Studio and OrcaSlicer (“Export plate sliced file”), with a plate picker and the slicer's own time and weight. A plain 3MF project has no G-code yet; open it in the 3MF viewer instead.
- Arcs (G2/G3), relative and absolute extrusion, firmware retraction and multi-tool changes.
What to look for before printing
- First layer: step to layer 1 and check the whole part is drawn and the lines touch.
- Supports: colour by feature type and look for overhangs printed in mid-air.
- Volumetric flow: most standard hotends manage about 10–15 mm³/s of PLA, high-flow ones much more. Red areas above your hotend's limit will under-extrude.
- Layer time: very short layers (small tops, thin towers) may not cool in time and droop.
About the numbers
Print time and filament come from the slicer's own comments when the file has them; those are the figures to trust. When it doesn't, the viewer estimates the time from distance and speed, which ignores acceleration and is usually on the short side. Line widths come from the slicer's comments or, failing that, are worked out from the amount of plastic extruded.
Questions
How do I view a G-code file online?
Drop it into the viewer at the top of this page. It opens in 3D straight away, with a layer slider, print time and filament use. Nothing is uploaded.
How do I open a .bgcode file?
Drop it here. Binary G-code from PrusaSlicer is decoded in your browser, so you can view it without converting it first.
How do I view the G-code of a Bambu Studio print?
In Bambu Studio, slice the plate and use Export plate sliced file to get a .gcode.3mf, then drop it here. Each plate's G-code can be viewed, with the slicer's time and weight.
Can I see how long a G-code file will take to print?
Yes. The slicer's estimate is read from the file and shown with the filament length and weight. Files without one get a rough estimate from distance and speed.
Does it work for large files?
Yes. Files are read in chunks in the background and drawn on the graphics card, so prints with millions of moves stay smooth on a desktop computer. Phones may run out of memory on very large files.
Can I edit G-code here?
No, the viewer is for checking a print. To change it, adjust the settings in your slicer and slice again.