What Is an ACF File?

How to open, edit, and convert ACF files

What to Know

  • Some ACF files are Adobe Custom Filter files.
  • Open one with Photoshop: Filter > Other > Custom.
  • Text-only ACF files can be converted with a text editor.

This article explains the several formats that utilize the ACF file extension. We'll look at how to open each kind and what your options are if you need to convert one so that it's usable with other software.

What Is an ACF File?

A file with the ACF file extension is most likely an Adobe Custom Filter file, a format that stores values that are to be used in Adobe Photoshop for manipulating the pixels that exist around a specific pixel.

Some files with this extension are associated with the Steam video game distribution platform as an application cache file, used to store information about downloads and updates.

ACF Files

If your ACF file isn't in either of these formats, it may instead be an X-Plane Aircraft file or an Agent Character Data file.

A less common use is as an Application Configuration file used in Microsoft Visual Studio, a format that holds certain attributes for an application. An even less common use for this file suffix is as a format used by Inmagic DB/TextWorks.

How to Open an ACF File

Your ACF file is most likely used with Adobe Photoshop, but only if it's an Adobe Custom Filter file. To open it in Photoshop, go to Filter > Other > Custom, and select Load.

Photoshop Custom filter load menu

If your specific ACF file is used with Steam, you should be able to open it as a text document using a simple editor like Notepad++. If not, try the GCFScape utility to open or extract any files out of the ACF file. This format is used in the most recent version of Steam, while GCF and NCF files were used in older versions.

X-Plane is a flight simulator that uses ACF files for storing aircraft properties like the plane's limits and engine power. If you're using a version of X-Plane newer than v9, then your file is most likely just text (others are in binary), meaning you could also open it in a text editor. You can read more about this format on the X-Plane Developer website.

Agent Character Data files are associated with the now-discontinued Microsoft Agent animation software. They describe a character and are saved with Agent Character Animation (ACA) files. Microsoft Agent Character Editor might be able to open it.

An Application Configuration File also uses this extension, and should be usable with Visual Studio.

If none of these applications are working, try Inmagic DB/TextWorks.

If you find that an application on your PC does try to open the file, but it's the wrong application, or you'd rather have another installed program open ACF files, see our How to Change the Default Program for a Specific File Extension guide for making that change in Windows.

How to Convert an ACF File

Converting an ACF file depends entirely on what it's used for (i.e., what format it's in). For example, you may be able to save an X-Plane Aircraft file to a new text-based format, but Photoshop's ACF file probably can't be used under any other format.

The best thing to do to check if your ACF file is able to be converted, is to open it in a compatible program, and then see if a File > Save As or Export menu exists.

Most formats, especially the more popular ones like PDF and DOCX, can be converted using a free file converter, but we don't believe this is the case for the formats described on this page.

Still Can't Open It?

ACF are common letters used in lots of file extensions, so it's easy to mix them up with other file formats. When this happens, you might try to open a file in a program that is incompatible with it.

For example, AFC looks quite a bit similar, but that extension is reserved for audio files in the Mass Effect 2 video game. It's obvious that an audio file like that can't open in Photoshop or a text editor.

ACFM is another one to consider. Adobe Composite Font Metrics files use that extension, and while it is an Adobe file, you can't use Photoshop to view it.

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