How do I open a .COMask file?

Drop a .COMask file onto Analyser at https://lab.valjdakosta.com/ and it is identified directly in your browser - no upload, no account and no software to install. A catch-all for rare and niche formats Analyser still identifies from their bytes: 3D caches and scans (Alembic ABC, FARO FLS/FWS), camera and design data (ARRIRAW ARX, Capture One masks, CATIA CGR), JBIG codestreams, firmware dumps (Binwalk), draw.io diagrams, OptimFROG DualStream audio, RTTTL ringtones, LaTeX style and class files, Sun Raster and Truevision TGA images, MPEG-2 streams, PVR/DVB recordings, Tiled tilesets, Windows Prefetch and Reaper project backups.

Can I open a .COMask file online for free?

Yes. Analyser is a free online .COMask identifier that runs entirely in your browser - your .COMask file never leaves your device, so there is nothing to upload and no software to install. It even works offline once installed.

.COMask file - what it is and how to identify it online

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Home › Formats › .COMaskID

What is a .COMask file?

COMASK is a Capture One mask - the saved selection data for a local adjustment in the Capture One raw photo editor.

Did you know: Because the mask is stored separately, an edit can reshape exactly where an adjustment applies without ever touching the original raw file.
Analyser handles .COMask alongside related formats such as .ABC, .AFL, .ARX and more.
In Analyser's format library, .COMask sits in the System & disk category.
What Analyser reads: A catch-all for rare and niche formats Analyser still identifies from their bytes: 3D caches and scans (Alembic ABC, FARO FLS/FWS), camera and design data (ARRIRAW ARX, Capture One masks, CATIA CGR), JBIG codestreams, firmware dumps (Binwalk), draw.io diagrams, OptimFROG DualStream audio, RTTTL ringtones, LaTeX style and class files, Sun Raster and Truevision TGA images, MPEG-2 streams, PVR/DVB recordings, Tiled tilesets, Windows Prefetch and Reaper project backups.
Depth of analysis: .COMask is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
Open a .COMask file: Drag a .COMask file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.
Related formats: .ABC · .AFL · .ARX · .BIE · .Binwalk · .CGR · .DIO · .FLS · .FWS · .H2V · .OFS · .PF · .RPP-bak · .RTX · .STY · .CLS · .SUN · .TP and more. See all supported file types.