G-code Inspector
The G-code Inspector is a Premium bottom panel that lets you view, search, and analyze the generated toolpath. It also displays configuration warnings that might affect print quality. It is available in the web app and the desktop app once a Premium license is activated.
Opening the Inspector
- Keyboard shortcut:
Ctrl+B(toggle open/close) - Click the header bar: Click "INSPECTOR" at the bottom of the screen
- Warning badge: Click the warnings badge in the sidebar
- Export G-code: If any blocking or review warnings exist, download opens this Inspector and lists them before the file save. Blocking issues still prevent generated-module export. Non-blocking warnings can continue with Export anyway.
Tabs
The inspector has two tabs:
Readiness Tab
Displays configuration issues organized by severity:
| Severity | Icon | Description |
|---|---|---|
| Blocking | 🛑 | Critical issues that prevent export. Must be fixed first. |
| Warning | ⚠️ | Non-critical issues that may affect print quality. |
| Info | ℹ️ | Helpful suggestions and notes. |
Click a warning to jump directly to the relevant parameter in the sidebar. This makes it easy to fix issues without hunting through settings. For a full list of Profile and SynthBlocks warnings and how to fix them, see Warnings reference.
G-code Tab
Displays the generated G-code with these features:
- Line numbers: Each line is numbered for easy reference
- Search: Find specific commands or coordinates
- Line selection: Click to select lines and highlight them in 3D
- Pagination: Large files load in batches for performance
Generating G-code for Preview
G-code is generated when you export, but you can preview it without saving:
- Switch to the G-code tab
- Click the Generate button
- Wait for generation to complete
Searching G-code
The search bar lets you find specific content:
- Type your search query (e.g.,
G1,Z50,retract) - Matching lines are highlighted in amber
- Use ▲/▼ buttons to jump between results
- Current result shows a brighter highlight
Common search queries:
| Query | Finds |
|---|---|
G0 | Travel moves |
G1 | Print moves |
Z | Z-axis changes |
E- | Retractions (negative extrusion) |
G4 | Dwell commands |
M104 | Hotend temperature commands |
M140 | Bed temperature commands |
Line Selection and 3D Highlighting
One of the most powerful features: selecting G-code lines highlights them in the 3D preview.
Selection Methods
| Action | Effect |
|---|---|
| Click | Select a single line (clears previous selection) |
| Ctrl+Click | Toggle a line in the selection (add/remove) |
| Shift+Click | Select a range from the last clicked line |
How It Works
- Click a G-code line in the inspector
- The corresponding toolpath segment highlights in red in the 3D viewer
- Use Ctrl+Click to build up a multi-line selection
- Use Shift+Click to select a range of consecutive lines
Use Cases
- Identify problem areas: Select lines around a visual artifact to understand what's happening
- Verify layer transitions: Select lines at layer boundaries to confirm proper Z movement
- Check retraction: Find
E-commands and select them to see where retractions occur - Validate travel moves: Select
G0commands to see travel paths
Pagination
Large G-code files can have tens of thousands of lines. The inspector uses pagination for performance:
- 1500 lines are shown initially
- Load more: Click to load the next batch
- Load all: Shows the entire file (may be slow for very large files)
Warnings Reference
Common warnings you might see:
| Warning | Cause | Fix |
|---|---|---|
| Temperature below safe minimum | Nozzle temp too low | Increase temperature |
| Temperature above safe maximum | Temp exceeds material rating | Decrease temperature |
| Print exceeds machine limits | Model too large | Reduce total height or check machine profile |
| Invalid flow rate | Flow is 0 or negative | Set flow rate > 0 |
| NaN in configuration | Corrupt value | Reset the affected parameter |
Keyboard Shortcuts
| Shortcut | Action |
|---|---|
Ctrl+B | Toggle inspector open/close |
Enter / Space | Activate selected warning (jump to parameter) |
Tab | Navigate between G-code lines |
Tips
- Use the inspector with the layer slider to isolate specific height ranges
- Generate G-code after major changes to catch issues early
- The warning count badge in the header updates in real-time
- Blocking warnings prevent export — fix them to enable the export button