.PAC File Extension

.PAC File Extension

File Type 1

Proxy Auto-Config File

Developer Netscape
Popularity
3.8  |  65 Votes
Category Web Files
Format Text

What is a PAC file?

A PAC file is a configuration file used by web browsers to select an appropriate proxy server. It contains one or more JavaScript functions with one of them named FindProxyForURL, which defines rules for choosing a proxy server based on a given URL. PAC files are used for controlling and load-balancing Internet traffic, especially in corporate environments.

More Information

PAC files are enabled in web browsers by entering the PAC file URL in the proxy connection settings, or by using the Web Proxy Auto-Discovery (WPAD) protocol. When executed, a PAC file returns a string with one or more proxy server URLs. PAC files are typically hosted on a web server and are named proxy.pac.

Since PAC files contain the configuration in plain text. You can use a text editor, such as Microsoft Notepad or Apple TextEdit to view or modify the files.

NOTE: The PAC file format was originally released in 1996 for use by Netscape Navigator 2.0.

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Programs that open PAC files

Mac
Included with OS
Linux
Updated August 7, 2019
File Type 2

PAC Subtitles File

Developer Screen Subtitling Systems
Popularity
3.8  |  22 Votes
Category Video Files
Format N/A

What is a PAC file?

Proprietary subtitles format created by Screen Subtitling Systems; used for synchronizing closed captions with a video timeline; can be edited with subtitle editing software such as EZTitles and converted to more standard formats, including .SRT and .SUB.

Programs that open or reference PAC files

Updated February 7, 2018
File Type 3

SBStudio II Song File

Developer SonicSpot
Popularity
3.0  |  12 Votes
Category Audio Files
Format Binary

What is a PAC file?

Song format, called a PAC or package file, used by SBStudio; made up of data blocks that store song information and audio data.

Programs that open PAC files

Windows
SBStudio II
Updated February 24, 2010
File Type 4

STAD Graphic File

Developer STAD
Popularity
2.5  |  13 Votes
Category Raster Image Files
Format Binary

What is a PAC file?

Image format used by the STAD program for Atari ST systems; saved as a black and white image with a resolution of 640x400 pixels; considered a high-resolution graphic for Atari computers.

Programs that open PAC files

Windows
Updated February 24, 2010
File Type 5

Hedgehog Engine 3D Model

Developer Sonic Team
Popularity
2.0  |  1 Vote
Category Game Files
Format Binary

What is a PAC file?

A PAC file is a 3D model used in a video game developed by SEGA or Sonic Team. Notably, the games Sonic Forces and Sonic Lost World use 3D models saved as PAC files.

More Information

PAC files are 3D models used in games that use the Sonic Team's Hedgehog Engine game engine. In addition to Sonic Forces and Sonic Lost World, Puyo Puyo Tetris 2, Sakura Wars, Mario & Sonic at the Olympic Games Tokyo 2020, Mario & Sonic at the Rio 2016 Olympic Games, and Olympic Games Tokyo 2020 - The Official Video Game use PAC files.

Most players who play these games will never encounter the games' PAC files. However, some enthusiastic modders have created tools that allow them to extract, edit, and create their own PAC files.

How do I open a PAC file?

You can use HedgeLib (cross-platform) to extract PAC files from a Hedgehog Engine game. Then, you can use Noesis (Windows) to open the files' contents and convert them to other 3D model formats.

After you've finished editing your PAC file, you can use HedgeLib to repackage the file and insert it into a Hedgehog Engine game.

Programs that open or reference PAC files

Windows
Free
Mac
Linux
Updated September 7, 2021

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