See what your machine will do — before it does it.
GCodeEdit is an offline CNC G-code editor and 3D toolpath backplotter. Open a posted program, watch it cut your stock in 3D, and find the mistakes while they are still cheap to fix.
$129 one-time · no subscription
The step between CAM and cutting
Your CAM software makes the toolpath. Your controller runs it. GCodeEdit is the review in between — the one that catches the rapid ploughing through your workpiece, the cut that runs off the stock, the tool that was never given a diameter, and the code your controller is going to reject.
What it does
- Interprets a program block by block, the way a controller would
- Draws the full toolpath in 3D, with rapids, feeds, arcs and probe moves
- Simulates material coming off your stock, shaped to the cutter you used
- Reports problems by severity and category, with line numbers
- Fixes what can be safely fixed, in one click
- Edits the program and re-checks it in the same window
What it is not
- Not a machine controller — it never connects to your hardware
- Not a sender, and there is no DNC
- Not CAM — it does not generate toolpaths from models
- Not machining verification, and it does not check for collisions
The stock simulation is an approximate heightmap for backplot review. Always verify a program before you run it.
What you get
Twelve dockable panels, any of which can be torn off to a second monitor.
A 3D preview built for real CAM output
Orbit, pan and zoom with the mouse, or use the trackpad mode with two-finger pan and pinch zoom. Click a face of the ViewCube for a straight-on view. Switch between program, machine and workpiece coordinate space, filter rapids, feeds and arcs, and overlay the machine travel envelope, the stock box, the cutter envelope, and a cutter-compensation preview of the G41/G42 offset path.
Level-of-detail rendering keeps programs of tens of thousands of blocks responsive, so real CAM output doesn't need trimming before you open it.
Material removal you can actually see
Set your stock — fitted automatically from the toolpath, or entered by hand — and watch the program cut it. The simulation is shape-aware: ball ends cut spherical footprints, V-bits conical ones, drills and flat endmills their own.
View the result as a cut-depth heatmap — as in the previous image — or as a textured surface in pine, oak, cherry or plywood. Hide the uncut top to see only the machined areas. Cylindrical stock is supported for rotary work.
Diagnostics that tell you what to do
Problems are sorted by severity and by category — parser, program flow, unsupported code, motion, arc, travel, tool, stock. Repeated problems collapse into one row with an occurrence count, so a single bad tool does not bury you in thousands of lines.
Every issue gives you a line number, an explanation, and a jump to the relevant reference entry. Where a safe rewrite exists, a Quick Fix applies it — converting a rapid to a feed move, expanding the stock, repairing a missing tool diameter — with a Fix All for batch-safe matches. Issues with no defensible fix deliberately offer none.
Machines and tooling, kept separate
Eight starter machine profiles cover common Mach3/Mach4, LinuxCNC, Fanuc, grblHAL and generic router and mill setups. A profile carries the controller dialect, display units, travel limits, rapid rates, arc tolerance, G28/G30 references, and behaviours such as whether a T word loads the tool and whether M1 stops the program.
Tool tables are held independently of machine profiles, so one cutter library serves several machines — up to 256 tools, each with shape, diameter, corner radius, flute length, stickout and holder geometry.
A full picture of the program
Program Analysis reports review status and a recommended next action alongside machine setup validation, travel limits, segment counts and lengths, path-control counts, and an estimated feed time. Modal State shows around forty-five live values for whichever block you select — offsets, feed mode, spindle, coolant, compensation, tool readiness.
Replay steps through the program block by block or plays it back from 0.25× to 10×, indexed against estimated feed time rather than segment count, so scrubbing reflects how long the job actually takes.
An editor that knows G-code
CNC-aware syntax highlighting, a gutter that marks errors and warnings inline, find and replace, go to line, and jump to next issue. Autocomplete is backed by a 215-entry G-code and M-code reference with syntax, plain-language summaries, dialect notes and examples — all available offline.
Click a line to highlight its move in 3D, or click a move to jump to its line.
4th-axis support (beta)
Optional A-axis support: degree-based moves, simultaneous linear and rotary motion, a workpiece-relative view, and cylindrical stock. Enabled per machine profile, and deliberately fails closed rather than approximating unsafe cases.
Batch checking
A command-line analyzer ships alongside the app. Point it at one program or a whole directory and get a review summary, or JSON on a stable versioned contract you can wire into shop automation.
Reports and handoff
Export an analysis as JSON, carrying diagnostics, stock issues, source hashes and the profile and tool context. Whoever opens it sees exactly what you saw, and can apply your setup with one click.
Compatibility
Five controller dialects, seven file extensions, inch and metric.
| Controller dialects | Generic, Mach (Mach3 / Mach4), LinuxCNC, Fanuc, grblHAL |
|---|---|
| File types | .gcode .gco .nc .ngc .tap .cnc .gc |
| Axes | 3-axis X/Y/Z fully supported. Optional 4th-axis (A) support (beta), enabled per machine profile. |
| Units | Inch and metric (G20 / G21), including detection of programs that mix the two |
| Work offsets | G54–G59.3, extended G54.1 Pn fixtures, G52 local offset, G92 offset, G10 L2 / L20 |
| Canned cycles | G73, G74, G76, G80–G89, plus G12 / G13 circular pockets, with G98 / G99 retract handling |
| Also interpreted | Cutter compensation G40–G42, coordinate scaling and rotation, polar mode, inverse-time and per-revolution feed, constant surface speed, probing G38.2–G38.5, subprograms M98 / M99 |
| Automation | JSON export from the included command-line analyzer, for scripting and batch checks |
System requirements
| Windows | macOS | |
|---|---|---|
| Operating system | Windows 11, 64-bit | macOS 12 Monterey or later |
| Architecture | x64 | Apple Silicon and Intel |
| Graphics | OpenGL-capable GPU | OpenGL-capable GPU |
| Disk space | About 150 MB | About 150 MB |
| Network | None. Works entirely offline. | None. Works entirely offline. |
Pricing
One purchase. It keeps working. No subscription, no account, no cloud, and nothing to renew.
$129, once
A perpetual licence for GCodeEdit 1.0 on Windows and macOS. No recurring fee, no seat management, no activation server.
Everything included
Every feature on this page, plus the command-line analyzer. There is no reduced tier and nothing held back behind an upgrade.
Nothing collected
No telemetry, no analytics, no crash reporting. The application makes no network connections at all.
Please read before buying. GCodeEdit previews local programs only. It does not connect to or operate CNC hardware, and it is not CAM — it does not generate toolpaths.
The stock simulation is an approximate heightmap intended for backplot review. It is not machining verification, and it does not check for collisions with holders, fixtures, clamps or machine structure. You remain responsible for verifying any program before you run it, and for safe machine setup and operation.
Questions
Does GCodeEdit control my machine?
No. It has no connection to CNC hardware of any kind — no serial, no USB, no network link to a controller. It reads and writes local files, and that is all. It is not a sender and there is no DNC.
Is this CAM software?
No. GCodeEdit does not generate toolpaths from models or drawings. It reviews and edits G-code that already exists, whether that came out of Fusion, Vectric, a generator script, or your own hands. It is complementary to CAM, not a replacement.
Is the stock simulation accurate enough to skip a dry run?
No, but it can help find problems early and save time. The simulation is a heightmap approximation for backplot review — it models the cutter shape, but it doesn't check for collisions with holders, fixtures, clamps or machine structure, and it can't guarantee your controller executes a program exactly as previewed. Think of it as a strong first pass, not your only check before cutting.
Which controllers does it understand?
Generic, Mach (Mach3 and Mach4), LinuxCNC, Fanuc and grblHAL, each selectable per
machine profile. Eight starter profiles ship with the application, covering common
router and mill setups in both inch and metric, and you can build your own or import
and export them as .ini files.
Does it handle 4-axis work?
There is optional A-axis support, currently beta: degree-based moves, simultaneous linear and rotary motion, a workpiece-relative view, and cylindrical stock. It is enabled per machine profile and it deliberately fails closed — canned cycles, probing and cutter-compensated moves on the A axis are blocked rather than approximated. It's used regularly in testing, but it hasn't seen the mileage of the 3-axis path yet.
How large a program can it handle?
There's no fixed limit. Level-of-detail rendering and cached geometry keep the 3D preview responsive on large, dense CAM output rather than choking on it.
Is there a free trial?
Not at the moment. If you are unsure whether GCodeEdit fits your workflow, email us before buying and describe what you are trying to do — we would rather answer that than have you buy the wrong thing.
Does it need an internet connection?
Never. GCodeEdit makes no network connections at all — not for licensing, not for updates, not for telemetry. It runs identically on a shop machine that has never been online. The built-in G-code reference and workflow guide are included in the application, not fetched.
Can I use it on more than one computer?
Your licence follows the store account you bought it with, under that store's normal device and family-sharing rules.
Is it available for Linux?
Not as a distribution today — Windows and macOS are the supported platforms. The application does build for Linux, so if that is what you run, get in touch and tell us what distribution you use. Enough interest and it becomes worth supporting properly.
Still have a question? Contact us.
Privacy
GCodeEdit collects nothing.
There are no accounts, no telemetry, no analytics, no advertising and no crash reporting. The application makes no network connections of any kind, so there is nothing to send and nothing for us to receive.
Information we collect
None.
Information stored on your device
So that the application behaves consistently between sessions, GCodeEdit saves the following locally. This never leaves your computer, and we never see it:
- Application preferences and window layout
- Machine profiles and tool tables you create
- Per-program workpiece and stock settings
- Your recent-files list
- An automatic recovery copy of unsaved work, so an unexpected shutdown does not lose your edits
On Windows this lives under your user profile's application data folder; on macOS, under your user Library folder. Removing the application and its settings removes it, and you can delete it yourself at any time.
Files you open
G-code programs, profiles, tool tables and reports are read from and written to locations you choose. GCodeEdit does not upload, copy, index or share them.
Third parties
There is no advertising, no third-party analytics, and no third-party SDK that collects data. The application is built with the Qt framework, which is a software library compiled into the product and does not collect information on our behalf.
If you bought GCodeEdit through a store, that store handles your purchase under its own privacy policy, which we do not control. We receive only aggregate sales reporting, which does not identify individual customers to us.
Your rights
Because we hold no personal data about you, there is nothing for us to disclose, correct, export or delete on request. Rights such as those under the GDPR and CCPA concern data a company holds; we hold none.
Changes
Any revision will be published on this page with a new effective date. Since the application collects nothing, a change would be a clarification rather than a new collection practice.
Questions? Contact us.
Support
The fastest way to reach us is our contact page. We aim to reply within two business days — GCodeEdit is made by a small team, so please allow for that; there is no phone support.
What to include
- Your GCodeEdit version (Help ▸ About GCodeEdit) and your operating system version
- What you expected to happen, and what happened instead
- The controller dialect and machine profile you were using
- If it is safe to share, the G-code program — or a trimmed-down version that still shows the problem
Reports that include a program are resolved much faster, because the behaviour can be reproduced exactly.
What support covers
- How a feature works
- Setting up machine profiles, tool tables and workpiece stock
- Incorrect interpretation, rendering or diagnostics
- Bug reports and crashes
- Licence and installation problems
What it does not cover
- Operating, configuring or troubleshooting your CNC machine or controller
- CAM programming, post-processor development, or speeds and feeds advice
- Reviewing or approving your G-code for safe machining — responsibility for what you run stays with you
- Other manufacturers' software
Reporting a suspected interpretation error
These are the reports we care about most. If GCodeEdit shows a toolpath or modal state that your controller does not actually produce, please send the smallest program that reproduces it, your exported machine profile, your controller make, model and firmware version, and what the controller really does.
Refunds
Purchases are handled by the store you bought from, and refunds follow that store's policy. We cannot process refunds directly. If the problem is a bug, get in touch first — we would rather fix it.
Licence
GCodeEdit is proprietary software. Buying it grants you a perpetual, non-transferable licence to install and use it on devices you own or control, under the device rules of the store you bought it from — the licence is yours to keep, though the software and its source code remain ours. The full End User License Agreement is included with the application and presented at installation.
Limits of liability
- You own your work. The G-code programs, machine profiles, tool tables and reports you create are yours. We claim no rights in them and never see them.
- GCodeEdit reviews and previews G-code — it doesn't author it and it doesn't run it. Your CAM or your own hand wrote the program; your controller executes it. GCodeEdit models one plausible interpretation and reports what it finds.
- The simulation is an approximation for backplot review, not collision-checked verification. Always confirm a program before you run it.
- Provided as is, to the extent the law allows, with liability capped at what you paid. Nothing here limits your non-excludable statutory consumer rights.
- Qt is included under the LGPLv3, dynamically linked. You may relink it, and reverse engineer the software as far as needed to debug changes you make to Qt. Otherwise, redistribution, resale, and reverse engineering are reserved to us.
© 2026 Rivers Edge Software. All rights reserved. GCodeEdit includes third-party components under their own licences; those notices ship with the application.