IFFSnooper Index



IFFSnooper is an IFF file reader for the Macintosh.

IFF files were first developed by Electronic Arts in 1985 and used for many years before the Sims, particularly on the Amiga computer sytem, but we are interested in the IFF files used to store object data for the Maxis/Electronic Arts game The Sims, its expansions, and The Sims Online (TSO)/EA-Land, an on-line version of the game which ran from 2002 until 2008.

Later versions of the Sims games, i.e. The Sims 2 and its expansions, and The Sims 3 and its expansions, use different file formats such as DBPF files. IFFSnooper does not handle object files for these later versions.

Current release version: IFFSnooper 1.2.4 (released 11 dec 2011)

Current test version: IFFSnooper 1.2.5d1 (private testing)
IFFSnooper is a work in progress.

What IFFSnooper does

IFFSnooper opens up Sims 1 IFF files (usually identifiable in the Finder by the .iff file extension) and displays their resources. Some of these are editable.

OS9 interface

The IFFSnooper tab panel interface, Mac OS 9 version

OSX metal interface

The IFFSnooper tab panel interface, MacOS X 10.6.8 (IFFSnooper 1.2.4)

IFFSnooper can open up other Sims 1 files such as wall files ( .wll files), floor files ( .flr files) and .FAM files since these are all IFF files with alternate file extensions.

You can also use IFFSnooper to make your own walls, floors and simple objects from imported graphics.


IFFSnooper should run on any PowerPC Macintosh running OS 8.5 or higher. It has been tested on MacOS versions 8.6 to 10.6.8 (Snow Leopard). The IFFSnooper version for OS X is Carbonized and needs Carbon version 1.2.5 or higher.

IFFSnooper is compiled as a PowerPC application which runs without problems on Intel-based Macs under OS 10.6 (Snow Leopard) with Rosetta.

IFFSnooper will not run under OS 10.7 (Lion) or later versions.

Where to find it

Current version

You can download IFFSnooper from the following sites:



Info-Mac Archive

SimLouvre Yahoo! group (group members only)


Program code and webpage copyright © 2002 - 2013 Peter Gould

All sprite object art on these pages is used for purposes of illustration only.

The Sims and The Sims Online (TSO)/EA-Land are trademarks or registered trademarks of Electronic Arts Inc.

About Resources

The following resources can be displayed in the main tab panel.


Use the tab panel to select the resource you are interested in.

Navigate -- Next Resource or
Navigate -- Previous Resource
to view the next or previous resource of the same type, as written in the IFF file. Resources are not necessarily found in any particular order within the IFF file, so it may be easier to navigate a complex set of resources via the
Navigate -- **** resource list
(where **** is the current resource type). This method provides the most navigation options.

Navigation Submenu OSX

IFFSnooper tab panel navigation submenu (IFFSnooper 1.2.3, MacOS X 10.5.2 Intel)

There are Previous and Next navigation buttons on the resource tab panels.

Navigating SPR# and SPR2 resources
To change the current sprite frame view use the menus
Navigate -- Next Frame or
Navigate -- Previous Frame

or use the buttons on the SPR2/SPR# tab panel.

Floor files use separate SPR2 files for each magnification, and don't have rotations.
Wall files use separate SPR# files for each magnification.
Thought balloon SPR# files (in Sprites.iff) don't have rotations.

Using IFFSnooper to make and edit objects

This page was getting too long so i have broken it into subsections.

What are these resources?

Making new IFF files

Making Floor Tiles

Making Walls

Editing OBJD resources

Editing the GUID

Editing text strings

Editing draw groups

Editing sprites

Editing menu resources

Editing other resources


Version History...

There is complete version history here. There are shorter update notes at the bottom of this page.


For details about the IFF file format: The Sims Technical Library

aq For Mac-friendly custom objects.

around the sims For objects, skins and some Mac Sims utilities.

Persimmon Grove For Mac-friendly objects (and an IFFSnooper tutorial).

SimFreaks For objects, skins and other neat Sims stuff.

SimSlice for custom "hacked" objects.

For programmers...

The REALBasic project file for IFFSnooper 1.2.4 in hqx format.

You will need a copy of REALBasic version 4.5.3 in order to run or compile your own version.
and the following plug-in
Copyright © 1999-2003, Micono Utilities. All rights reserved.

Sample output...

sample HTML output


This software is distributed 'as is': no warranties are made, either expressed or implied. Use it at your discretion.

UPDATE NOTES 2002 - 2012

Version 1.2.4

11 Dec 2011

Version 1.2.3

31 Mar 2008

Version 1.2.2a

11 Jan 2007

Version 1.2.2

29 Oct 2006

Version 1.2.1

13 May 2006

Version 1.2.0

12 Mar 2006

Version 1.1.9

04 Aug 2005

Version 1.1.8

30 Apr 2005 Version 1.1.7

15 jan 2005

Version 1.1.6

29 nov 2004

Version 1.1.5

12 oct 2004

Version 1.1.4

09 aug 2004

Version 1.1.3

19 apr 2004

Version 1.1.2

07 feb 2004

Version 1.1.1

09 nov 2003

Version 1.1.0

20 sept 2003

Version 1.0

22 july 2002