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Details of extension .a1

On this page, we're going to take a closer look at the .a1 file extension. We'll explain what exactly a .a1 fileformat is and how you can use it. If you're interested in learning more details about this type of file, we'll show you where to find them. And if you ever need to convert .a1 files into different formats, we'll give you some tips on how to do that too. Let's see the 2 file formats associated with this file extension!


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a1 file - Free Pascal Compiled Archive

Free Pascal Compiled Archive

The A1 file is a Free Pascal Compiled Archive. Free Pascal is a free, portable, open source, Pascal and Object Pascal compiler.
Category: Development files
Application: Free Pascal
Program name: -
Mime-type: application/octet-stream
Magic bytes (HEX): -
Magic string (ASCII): -
Related extensions:
.ppu FreePascal Compiled Unit
.a Free Pascal Archive
.sw Free Pascal Assembler Data
.oo FreePascal Object
ai file - OpenEdge ABL After Image

OpenEdge ABL After Image

The AI file is an OpenEdge ABL After Image. OpenEdge Advanced Business Language is a business application development language created and maintained by Progress Software Corporation (PSC).
Category: Development files
Application: Progress OpenEdge
Program name: -
Mime-type: application/octet-stream
Magic bytes (HEX): -
Magic string (ASCII): -
a1, a2
Related extensions:
.wsdl Web Services Description Language Document
.resources Visual Studio .NET Resources Data
.discomap Visual Studio .NET Discovery Map Data
.wsad OpenEdge Web Services Application Descriptor

The .a1 file extension might not only belong to a single type of file, there could be various kinds that use it. Keep in mind that files with the .a1 extension may contain various content types. If you have helpful information about this extension, write to us!

Could someone have spelled the .a1 file extension wrong?

In our database, we came across the following similar extensions:

.al A-Law Compressed Audio File
.q1 WinAMP Equalizer Presets
.aq Ancestral Quest Database
.x1 X1 Saved Search
.z1 Z-machine Z-code File
.aw Answer Wizard Index

The .a1 extension is frequently misused

People sometimes confuse the .a1 filename extension. Based on the searches on our site, here are the most common misspellings from the past year.

al (1), q1 (1), aq (1), x1 (1), z1 (1), aw (1)

Having trouble opening a .a1 file?

If you want to open a .a1 file on your computer, you just need to have the appropriate program installed. Incorrect settings for the .a1 association can trigger this error.

Windows can't open this file:

File: example.a1

To open this file, Windows needs to know what program you want to use to open it. Windows can go online to look it up automatically, or you can manually select from a list of programs that are installed on your computer.

To change file associations:

  • Right-click a file with the extension whose association you want to change, and then click Open With.
  • In the Open With dialog box, click the program whith which you want the file to open, or click Browse to locate the program that you want.
  • Select the Always use the selected program to open this kind of file check box.

Supported operating systems

Windows Server 2016/2019/2022, Windows 7, Windows 8, Windows 10, Windows 11, Linux, Mac OS X, macOS, iOS, Android