Free online GTP to PNG converter

PCB fabrication and documentation tools may produce a .gtp Gerber top-paste layer, while image editors, web pages, and reports commonly require .png. Converting it creates a viewable raster image for inspection or sharing, but does not preserve editable PCB-layer data.

What the GTP format is

In the CAD and PCB context, GTP is usually a Gerber top-paste layer file. It describes the solder-paste openings for the component side of a printed circuit board and is generated by PCB design or CAM software such as KiCad, Altium Designer, Autodesk Fusion electronics tools, and other Gerber exporters.

A GTP file normally uses RS-274X Gerber syntax and may contain embedded aperture definitions. Older Gerber files can depend on separate aperture or format information, so a converter may need the complete fabrication output rather than only the .gtp file.

What the PNG format is

PNG is a lossless raster image format supported by browsers, office applications, image editors, and documentation systems. It supports transparency, making it suitable for displaying the copper, mask, paste, or silkscreen geometry over a chosen background.

PNG is useful when the layer only needs to be viewed, annotated, embedded in a report, or shared with someone who does not have PCB/CAM software. It does not retain Gerber coordinates, apertures, units, polarity, layer functions, or manufacturing metadata.

How to convert GTP to PNG

For a graphical desktop conversion, open the file in gerbv, an open-source Gerber viewer:

1. Start gerbv and choose File → Open.
2. Select the .gtp file. If the layer appears mirrored, incorrectly scaled, or empty, verify the Gerber file's units, coordinate format, and polarity, or open the complete Gerber job.
3. Set the displayed layers and background as required. Hide other layers if the PNG should contain only the top-paste layer.
4. Choose File → Export → PNG if available in the installed version, then set the output dimensions or resolution and save the result as top-paste.png.

Gerbv can also export from a terminal:

gerbv -x png -o top-paste.png board.gtp

On systems where the long-option form is provided, the equivalent command is:

gerbv --export=png --output=top-paste.png board.gtp

You can also convert the file for free on 101convert.com without installing software. Upload the GTP file, choose PNG as the output, start the conversion, and download the generated image.

Quality and compatibility limits

PNG resolution determines how accurately narrow pads and small paste apertures appear. Use a sufficiently high pixel size or DPI for inspection; enlarging a low-resolution PNG cannot restore lost geometry.

Gerber coordinates describe manufacturing geometry, not a normal picture. A PNG export is therefore a visual rendering: it cannot be re-imported as an equivalent editable Gerber layer without tracing or regenerating the layer from the original PCB design.

Check the output against the original in a Gerber viewer, especially for board origin, units, mirroring, rotation, scaling, polarity, and transparent-background handling. For fabrication, submit the original Gerber files, not the PNG.