How to open a .pas file (Windows, Mac, Linux)

Q: Why can't I open my .pas file?

Usually your computer lacks an app that understands Pascal. Install one of the apps listed here, or convert the file to a more common format.

A .pas file is a Pascal / Delphi Source File. If double-clicking does nothing, your computer simply does not have an app that reads Pascal yet. Here is how to fix that on each operating system, using free software wherever possible.

Open a .pas file step by step

Confirm the file really is a .pas. Drop it into the WhatFileType file identifier, which reads its signature without uploading anything.
On Windows, open it with Delphi or Lazarus (Free Pascal).
On Mac, use Lazarus (Free Pascal) or VS Code.
On Linux, try Lazarus (Free Pascal) or VS Code.
Still stuck? Convert the .pas to exe (compiled), which opens more widely.

Best apps to open .pas files

Windows

Delphi
Lazarus (Free Pascal)
any text editor

macOS

Lazarus (Free Pascal)
VS Code
any text editor

Linux

Lazarus (Free Pascal)
VS Code
any text editor

Before you open it: Caution. A .pas file is program source. Compiling and running it executes its code; review unfamiliar files first.

Frequently asked questions

Why can't I open my .pas file?

Almost always because no installed app understands Pascal. Install one of the apps above, or convert the file to a format your existing software already reads.

How do I open a .pas file?

Any text editor shows the source. To compile it, use Free Pascal (with the Lazarus IDE) or Delphi, depending on which dialect the code targets.

Is Pascal still used?

Yes. Delphi remains common in business and industrial Windows software, and Free Pascal with Lazarus keeps the language alive cross-platform and open source.