View Gerber files, check the board and build its enclosure

Before you order a board, look at what you send to the fabricator. Instruments → Gerber viewer… opens the fabrication files themselves – Gerber layers (RS-274X with X2 attributes) and Excellon drill files – renders them, measures the board and runs a few quick checks. It uses the same engine as the ohmforge-gerber-viewer tool, so the app and the tool give the same report and the same files.

Open your files

Open Instruments → Gerber viewer… and press Open Gerber files…. Choose the ZIP archive your design tool writes, or select the single layer and drill files together; you can also drop them onto the board view. To try the viewer first, press Load the example board (a 50 × 30 mm two-layer board) or Load the example with problems (the same board in older Eagle style, with two deliberate faults).

The status line sums up the result, for example Board 50 × 30 mm. Files: 8. Holes: 18. All checks passed. The files stay on your device and are not saved in the project.

Layers and sides

The Layers list shows every file with its colour, the recognised function and how it was recognised: X2 attribute (the file says what it is) or File name (KiCad, Altium, Eagle and EasyEDA conventions). If a file was recognised wrongly, choose the right function in its list box; the report is recalculated.

• View: Realistic board shows solder mask, exposed copper on the pads, silkscreen and holes; Coloured layers stacks every layer in its own colour.
• Board side: Bottom side (mirrored) shows the board as you see it from below.
• Untick a layer to hide it.

Zoom, pan and measure

Use the mouse wheel to zoom at the pointer and drag to pan, or the Zoom in, Zoom out and Fit the board buttons. With the board view focused, + and − zoom, the arrow keys pan and 0 fits the board.

Press Measure, then click two points: the line below the view shows the distance with Δx and Δy. Points snap to pad and hole centres, so measuring between two mounting holes of the example gives exactly Distance 43 mm. Without a mouse, pan the centre cross onto a point and press Enter.

Read the report

Under Report you find the Board size, the numbers of Holes, Slots and Vias, the Narrowest trace, the Smallest clearance (sampled), the Smallest annular ring and the Smallest hole-to-edge distance. Checks lists each rule with ✓ or ✗; the example with problems shows six vias with only 0.05 mm of copper around the drill and a hole 0.249 mm from the edge. The clearance is measured on a fine grid, so a value within one grid step of the rule is borderline. The Layers and Drill table tables give the details per file and per drill size.

Use the outline for the enclosure

Under Use the outline for the enclosure, holes between 2 and 4.5 mm are suggested as mounting holes. Check the ticks – tick Show every hole to choose others – and press Use the outline for the enclosure. Ohmforge writes the outline and the ticked holes into the board model, moved so the lower-left corner is at 0, 0, and opens Board & enclosure…. Add the parts and connectors there and generate the case. Undo restores the previous board model.

Download the results

The buttons at the end download the board image (PNG) of the side you are viewing, the top and bottom views (SVG), one SVG per layer (ZIP) and the full report with every hole (JSON).