PCB Gerber Layer Reference Viewer
Lists the standard Gerber file layers required for 2/4/6/8-layer PCBs, marking required vs. optional files and naming conventions to help engineers verify fabrication packages.
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How to Use
- Select your PCB layer count (2, 4, 6, or 8 layers) from the dropdown at the top.
- The table below automatically lists all Gerber file layers applicable to that layer count, including file extension, layer name, function description, and whether the file is required by fabricators.
- Click "Copy File List" to copy all file extensions for the current layer count to your clipboard, making it easy to verify your delivery package is complete.
- Click "Load 4-Layer Sample" to quickly reset to the default 4-layer board view.
- Below the table, an RS-274X naming convention reference explains common prefixes (G/T/B/L/S/O/P/KO), inner-layer naming conventions, and the role of Excellon drill (.DRL) files.
Features
- Supports four layer-count configurations (2, 4, 6, 8 layers) and automatically filters the Gerber layer list to match.
- Covers the common Gerber layer set: top/bottom copper (GTL/GBL), top/bottom solder mask (GTS/GBS), top/bottom silkscreen (GTO/GBO), board outline / keep-out (GKO), top/bottom paste (GTP/GBP), inner copper layers (GL1–GL6), drill file (DRL), and drill drawing (GDD).
- Each layer is tagged as "Required" or "Optional" to indicate the minimum file set fabricators typically expect.
- One-click copy of all file extensions for the selected layer count, useful for verifying package completeness before submission.
- Includes an RS-274X naming convention reference card explaining common prefix meanings, inner-layer naming variations across EDA tools, and the role of Excellon drill files.
Use Cases
Pre-fabrication Gerber package verification
After exporting Gerbers, check the file list against the required layer count to avoid missing solder mask, silkscreen, or drill files that cause back-and-forth with the fab house.
Onboarding for junior PCB designers
New engineers can quickly learn what each file extension (GTL, GBS, GKO, etc.) corresponds to physically and functionally via the reference table.
Verifying inner-layer naming on multi-layer boards
Inner copper layer naming (GL1, GL2...) varies across EDA tools on 4/6/8-layer boards; use this tool to cross-check against the standard convention and reduce ambiguity with the fab.
Generating a delivery checklist
Copy the complete file extension list for a given layer count and paste it into a project handoff document or email as a file manifest for the PCB manufacturer.
FAQ
Can this tool parse an uploaded Gerber file directly?
No. This is a reference lookup tool — it displays the standard Gerber layer list and naming conventions based on the layer count you select. It does not parse or read actual Gerber file content.
How is "Required" vs. "Optional" determined?
"Required" marks the minimum file set fabricators typically need (copper, solder mask, silkscreen, keep-out/outline, drill file) — missing these blocks production. "Optional" files (e.g., bottom silkscreen, paste layers) depend on your design; for example, no bottom-side placement means no bottom paste file is needed.
Are all inner-layer files required for 6-layer and 8-layer boards?
Yes. For a 6-layer board the tool lists GL1–GL4 (4 inner copper layers) as required, and for an 8-layer board GL1–GL6 (6 inner layers), since these are typically power/ground planes or signal layers whose absence leaves the circuit incomplete.
Is the drill file (.DRL) considered a Gerber file?
No. Drill data is typically stored in Excellon format (.DRL or .TXT), which is a separate standard from RS-274X Gerber, but it's still a mandatory file for PCB manufacturing and is listed as required in this tool.