GBS File

What are GBS files and how to open them

Are you having problems opening a GBS file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your GBS files.

What is a GBS file?

GBS files have multiple uses, and GameBoy Sound System Dump is one of them. Read more about the other uses further down the page.

GameBoy Sound System Dump

We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

How to open GBS files

Important: Different programs may use files with the GBS file extension for different purposes, so unless you are sure which format your GBS file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested ten different GBS openers which you will find listed below.

Last updated: August 6, 2026

All known file formats using extension .GBS

While GameBoy Sound System Dump is a popular type of GBS-file, we know of 3 different uses of the .GBS file extension. Different software may use files with the same extension for different types of data.

Gerber Bottom Solder Mask File

A Gerber Bottom Solder Mask file with the .gbs extension describes the openings in the solder mask layer on the bottom (non-component) side of a printed circuit board (PCB). It is created during PCB design export so that a fabricator knows where solder mask should not cover the bottom copper pads, vias or test points. Because solder mask layers are "negative" in the Gerber specification, the shapes in .gbs represent areas to leave exposed, not areas to cover.

This file is produced by EDA (electronic design automation) or PCB layout software when generating fabrication (CAM) output for manufacturing. Designers export separate Gerber files for each layer of the PCB: copper, solder mask, silkscreen, paste, mechanical outlines, etc. The .gbs file specifically corresponds to the bottom solder mask layer; it's used alongside matching top solder mask (.gts), copper, silkscreen, paste mask, and mechanical layer files to form a complete fabrication dataset. Gerbv is one viewer that displays .gbs files correctly.

Technically, .gbs files are part of the Gerber format defined by Ucamco under the RS-274-X / Gerber X spec. In the spec, .gbs files are tagged with FileFunction "Soldermask,Bot" (bottom solder mask) and the image data uses negative polarity so that drawn or "flash" regions correspond to openings in solder mask over copper.

GBS opener for Windows

We have identified one GBS opener that is compatible with this specific type of GBS file.

OtterUI Binary Scene

We know that one GBS format is OtterUI Binary Scene. We have not yet analyzed in detail what these files contain and what they are used for. We're working on it.

Various apps that use files with this extension

These apps are known to open certain types of GBS files. Remember, different programs may use GBS files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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