Online Gerber Viewer

View and inspect Gerber files (RS-274X), Excellon drill data and ODB++ packages directly in your browser. Verify layer alignment, drill positions, trace routing, pad geometry and solder mask openings before submitting design files for fabrication. Catching errors in the Gerber viewer prevents costly fabrication delays and re-spins.

What to check

Layer alignment: overlay the copper layers to verify that vias connect the correct pads on each layer. Drill-to-copper registration is critical for via reliability — misregistered vias can break annular ring requirements and cause open connections. Solder mask: verify that mask openings expose the correct pads without exposing adjacent traces. Solder mask dams (the strips of mask between closely spaced pads) must be wide enough for reliable printing — minimum 3 mil (75 microns) for most fabricators.

Silkscreen: verify that reference designators and polarity marks are visible (not covered by solder mask or overlapping pads) and readable. Board outline: confirm that the board outline matches the mechanical drawing and that routing clearance is adequate along all edges. Drill data: verify that drill positions match pad locations on all layers and that drill sizes are correct for the specified via and hole types.

Common errors caught by Gerber review

Missing layers: Gerber export occasionally omits layers, particularly inner layers or the drill file. A missing layer is invisible in the design tool but causes fabrication to halt when the factory notices the incomplete data set. Wrong drill file format: metric vs imperial unit mismatch causes drill positions to shift, resulting in vias that miss their pads entirely. Inverted plane layers: negative-plane Gerber files exported as positive (or vice versa) create copper where there should be clearance and clearance where there should be copper.

Solder mask polarity errors: an inverted solder mask covers all pads and exposes all copper — exactly backwards from the intended result. Board outline missing or incorrect: without a defined board outline, the fabricator cannot route the board shape. An outline on the wrong layer or at the wrong scale causes dimensional errors in the finished board.

File formats

Gerber RS-274X is the standard format for copper, mask and silkscreen layers. Excellon is the standard drill file format. ODB++ and IPC-2581 are unified formats that package all layers, drill data, stackup information and net connectivity in a single file — preferred for complex designs because they eliminate the ambiguity of individual Gerber files.

After verifying your files, upload them for a fabrication quote. The engineering team will perform a full DFM review as part of the quotation process.