Convert KAP to WebP
Convert KAP to WebP online: the whole nautical chart raster decoded edge to edge, saved as a compact WebP image. Free, no sign-up.
Drop your KAP files here
Up to 50MB per file.
Conversion Settings
Files are encrypted and auto-deleted after conversion
How to Convert
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Upload your KAP files
Drag and drop or select KAP files from your device. You can upload multiple files at once.
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Configure Output
Choose any available WebP output options, then start the conversion.
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Download WebP files
Once conversion finishes, download your files individually or as a compressed ZIP archive.
Why convert KAP to WebP?
KAP is the BSB raster nautical chart format used by hydrographic offices and marine navigation software, holding a scanned chart image with its geographic calibration. The complete chart raster stored in the file is decoded by GDAL at its stored resolution, with its colour palette applied so the chart keeps its original colours.
WebP stores the rendered image in a modern, efficient format, so the file is noticeably smaller than an equivalent PNG or JPG.
Frequently Asked Questions
How do I convert KAP to WebP?
Drop your KAP file above and press Convert. Our servers read the chart with GDAL's BSB driver, expand its colour palette into a lossless PNG, then encode it in the format you chose. The result is saved as a compact WebP image, ready to download.
Which part of a KAP chart appears in the WebP?
The complete chart raster stored in the file, from edge to edge, at the resolution it was scanned at.
What reads the BSB data in a KAP file for the WebP?
GDAL's BSB driver, part of the open-source geospatial library used widely in mapping software. It reads the chart raster and its colour table, and the full-colour chart becomes the WebP.
How big is the WebP image from a KAP file?
The chart is rendered at its full native resolution, keeping every pixel of the scanned chart.
How much smaller is the WebP from a KAP file?
WebP typically produces files around a quarter to a third smaller than JPG at similar visual quality, and far smaller than PNG, while text and lines stay clear.
Is my .kap file kept private?
Your file is uploaded over an encrypted connection, converted on our servers and deleted automatically within 24 hours. We never read, share or keep your files, and no account is needed.