Free online GBR to PNG converter

A PCB fabricator, reviewer, or documentation system may require a visual PNG instead of editable Gerber manufacturing data. A GIMP brush may also need to become a PNG image for use outside GIMP.

What the GBR format is

.gbr is an ambiguous extension. In PCB production, it usually identifies a Gerber file containing the artwork for one board layer, such as copper, solder mask, silkscreen, paste, or the board outline. Gerber files describe coordinates, apertures, drawing commands, polarity, units, and other manufacturing geometry; they are generated by tools such as KiCad, Altium Designer, Autodesk EAGLE, and EasyEDA. Other Gerber layers commonly use extensions such as .gtl, .gbl, and .gto.

GIMP also uses .gbr for a brush file. A GIMP brush contains a grayscale brush mask and metadata such as its name and spacing. It is not the same format as a Gerber PCB file, so the file’s source application must be identified before conversion.

What the PNG format is

PNG is a raster image format supported by web browsers, operating systems, office applications, documentation tools, and image editors. It uses lossless compression and supports transparency, indexed color, grayscale, and truecolor images, making it suitable for rendered board layers, diagrams, screenshots, and brush previews.

PNG does not preserve Gerber apertures, layer identity, manufacturing polarity, coordinate precision, or fabrication semantics. It is a visual rendering and cannot replace the original Gerber files for manufacturing or dimensional inspection.

Convert a Gerber file with gerbv

gerbv is a dedicated open-source Gerber viewer for Windows, macOS, and Linux. It interprets Gerber commands, apertures, units, and polarity before rasterizing the artwork, so it is preferable to a generic image converter.

1. Open the file with File → Open, or run gerbv board.gbr from a terminal.
2. Check the displayed units, layer polarity, orientation, and artwork against the source design.
3. Use File → Export and select PNG in builds that provide the graphical export command.
4. Choose the output resolution and background or transparency settings, then save the file as board.png.

Gerbv also supports command-line export in standard builds:

gerbv --export=png --output=board.png board.gbr

Use the relevant resolution option shown by gerbv --help if the default is insufficient for fine traces, small pads, or drill features. To create a composite board image, load the related Gerber layers together before exporting. Excellon drill files are separate from Gerber files and must be loaded separately when the viewer supports them.

Use KiCad for PCB inspection and rendering

KiCad’s Gerber Viewer is another suitable desktop option. Open it from the KiCad application menu, use File → Open Gerber Files or the equivalent version-specific command, select the required layers, verify the layer colors and polarity, and use its image export command if available. Menu names and export formats vary between KiCad releases, so use the application’s help for the installed version.

Online PCB viewers from established manufacturers, including JLCPCB’s and PCBWay’s Gerber viewers, can be useful for a quick inspection and may offer image export. Their export controls change, and uploading a proprietary board exposes the files to a third party; use a local viewer when confidentiality, repeatability, or exact settings matter. Do not submit an unidentified .gbr file to a generic image converter because it may be a GIMP brush or may be decoded without Gerber-specific polarity and aperture rules.

Convert a GIMP brush with GIMP

1. Copy the .gbr brush into a directory listed under Edit → Preferences → Folders → Brushes.
2. Open the Brushes dock and select Refresh brushes, or restart GIMP.
3. Create a new image with File → New. Use a transparent background when the PNG must retain transparency.
4. Select the brush, set its size and foreground color, and click once on the canvas to render it.
5. Choose File → Export As, give the file a .png name, and confirm the PNG export settings.

This creates a raster sample at the selected size and color. PNG does not retain the brush’s spacing, name, mask behavior, or other GIMP-specific metadata. If the brush is intended for repeated use in GIMP, keep the original .gbr file.

Quality and compatibility limits

Gerber-to-PNG conversion is resolution-dependent. Select enough pixels or DPI to represent the smallest feature; enlarging the finished PNG cannot restore detail lost during rasterization. Record the intended physical dimensions and export resolution because a PNG alone does not provide reliable manufacturing scale.

Check transparent and negative-polarity layers carefully, especially copper and solder-mask artwork. A dark or light appearance can change when polarity is interpreted incorrectly. Retain the original Gerber set, job parameters, and drill files for fabrication and measurement.