SKC File

What are SKC files and how to open them

Are you having problems opening a SKC file or are you simply curious about its contents? We're here to explain the properties of these files and provide you with software that can open or handle your SKC files.

What is a SKC file?

A .SKC file is an ISIS Sketch file.

ISIS Sketch files (.skc) are proprietary binary sketch documents used by chemical drawing applications that follow the MDL/ISIS format lineage (now under BIOVIA). These files store detailed two-dimensional chemical drawings: atoms and bonds (including special query types), text labels, molecular reaction arrows, and graphical decorations. They are created by programs such as ISIS/Draw or BIOVIA Draw when designing molecular structures or reactions for scientific databases and publication figures.

These sketch files are typically produced within a chemical-structure editor when saving or exporting a structure in the ISIS Sketch format. The sketches are edited visually and often exchanged between programs that support chemical drawing standards. Because .skc keeps both structural data (atoms, bond order, stereochemistry) and graphical metadata (line styles, text placement, group labels), conversion to simpler formats (such as molfile) may lose some graphics or query information.

Internally these files are binary. Their file extension is .skc. They are distinguished by byte signatures that include the byte 0x01 at offset 0 and byte 0x02 at offset 4. Programs recognizing this signature assume it matches an ISIS Sketch file.

How to open SKC files

We have identified one SKC opener that is compatible with this specific type of SKC file.

Programs that open ISIS Sketch files

Last updated: August 13, 2026

Various apps that use files with this extension

These apps are known to open certain types of SKC files. Remember, different programs may use SKC files for different purposes, so you may need to try out a few of them to be able to open your specific file.

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File.org helps thousands of users every day, and we would love to hear from you if you have additional information about SKC file formats, example files, or compatible programs. Please use the links below or email us at submit@file.org to discuss further.