OFS is an OptimFROG DualStream file - a lossy-plus-correction audio format that pairs a small lossy stream with data to rebuild the original losslessly. OptimFROG is famous for some of the highest lossless compression ratios around, at the cost of being very slow to encode and decode. Analyser handles .OFS alongside related formats such as .ABC, .AFL, .ARX and more. In Analyser's format library, .OFS sits in the System & disk category.

How do I open a .OFS file?

Drop a .OFS 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 .OFS file online for free?

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

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

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Home › Formats › .OFSID

What is a .OFS file?

OFS is an OptimFROG DualStream file - a lossy-plus-correction audio format that pairs a small lossy stream with data to rebuild the original losslessly.

Did you know: OptimFROG is famous for some of the highest lossless compression ratios around, at the cost of being very slow to encode and decode.
Analyser handles .OFS alongside related formats such as .ABC, .AFL, .ARX and more.
In Analyser's format library, .OFS 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: .OFS 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 .OFS file: Drag a .OFS 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 · .COMask · .DIO · .FLS · .FWS · .H2V · .PF · .RPP-bak · .RTX · .STY · .CLS · .SUN · .TP and more. See all supported file types.