Merge G-code Files
LocalMerge multiple G-code files online — free, no upload, no sign-up. Intermediate M2/M30 end commands are stripped automatically; everything runs in your browser.
Drag files here, or click to browse
Supports GCODE, NC, GCO, TAP, CNC, NGC, TXT
Choose fileMerge multiple G-code programs; intermediate end commands (M2/M30) are removed and only the final one is kept.
What is it? G-code Merge concatenates several G-code programs (.gcode, .nc, .tap, .cnc, .ngc and more) into one file and removes intermediate end-of-program commands (M2/M30, including N-numbered lines and % wrapping) so only the final program keeps its end command. Runs entirely in your browser — nothing is uploaded.
TL;DR: Combine multiple G-code files into one continuous program.
How to use
- Add two or more G-code files (.gcode, .nc, .tap, .cnc, .ngc and .txt are accepted) — the Merge button stays disabled until you have at least two.
- Files are merged in the order you added them — drag rows to reorder, or use the up/down/remove buttons.
- Click Merge, then review the toolpath preview (local SVG) and the first-50-lines text preview, plus the NOTE comments at the top of the output about modal state and repeated tool changes.
- Copy or download `firstfilename-merged.gcode` and dry-run it before cutting.
FAQ
Are end commands removed?
Yes — all M2/M30 end commands in intermediate programs are removed (including N-numbered lines and % wrapping), each marked with a comment; only the final program's end command is kept.
Does merging change the machining order?
Programs are concatenated in the order added; coordinates, line numbers and modal words are never rewritten. Note that modal state carries across segment boundaries — see limitations.
Is it local?
Yes, merging happens in your browser.
How do I merge two G-code files?
Add both files, order them the way you want, and click Merge — the download is a single .gcode file with the intermediate end commands already stripped. No account and no upload: everything happens in your browser.
Is it free?
Yes — G-code Merge is free with a daily allowance and no sign-up. It is not a Pro-gated tool.
Which file extensions are supported?
The dropzone accepts .gcode, .nc, .gco, .tap, .cnc, .ngc and .txt; the merged output is always a single .gcode file.
Can I merge G-code files for sequential 3D printing?
Yes — concatenating programs is the usual way to queue prints or rejoin segmented files. Watch modal state: if an earlier program ends in G91 (incremental), G20 (inch) or M83 (relative extrusion), that mode stays active into the next segment. The output adds a NOTE comment at the top so you can insert a reset (G90/G21/M82) after the merge marker.
Why are the intermediate M30 commands removed?
M2/M30 end the program — leaving one in the middle would stop execution at the merge point. Every intermediate end command (including N-numbered lines and % wrapping) is removed and marked with a comment; only the final program's end command is kept.
Examples
- Merge 3 .gcode files in order → one download
- Before → after: intermediate M30 commands are removed, the last one is kept
Supported formats
Limitations
- Merged in the order added.
- All M2/M30 lines in intermediate programs are removed (with N-number prefixes and % wrapping); a comment marks each removal and the final program's end command is kept.
- Coordinates, line numbers and modal words are never rewritten — but modal state carries across segments: if an intermediate program ends in G91 (incremental), G20 (inch) or M83 (relative extrusion), that state stays active into the next program. A NOTE comment is added at the top of the output so you can insert a reset (G90/G21/M82) after the segment marker.
- Review the merged file before running a machine.
- Runs locally in your browser, nothing is uploaded.
Privacy
Privacy first: this tool runs entirely in your browser — your input and files never leave your device, and everything is cleared when you close the page.