Rebuilding thumbnails cache in iPhoto
Wed, 15 March 2006
iPhoto will rebuild the thumbnail cache, or rather ask you if you want it to be done, every time it feels the need. Sometimes this might not happen for a while and with a huge library your scrolling can become crawling if things go bad.
I have a library of some 1800 images and after doing clean OS X (Tiger) and iLife 06 install I have imported my images back but scrolling was, to say it mildly, a joke. After two days of using it iPhoto didn’t ask me to rebuild the thumbnails cache so I had to ask for it.
After exploring the menus and not finding anything there I have actually tried a few key-combinations while starting iPhoto up and there it was - hold Command and Option down while starting iPhoto. The result is the following prompt:

Now select what you want iPhoto to do and click Rebuild.
Update 06 Oct 2007 - The original article was written with iPhoto 06 in mind, but the same works with iPhoto 08. The only difference is that iPhoto 08 has an additional function to examine and repair file permissions for iPhoto gallery.
Related posts
Web hosting - UNLIMITED space and transfer - $ 6.95 per month
Posted in 
Aimee said: Wed, 4 October 2006 at 08:34
THANK YOU!!!!!
Anil Raghavan said: Sun, 8 October 2006 at 14:11
Thanks a lot. I’ve been having iPhoto troubles as well. And I’ve been trying to find the darned Rebuild Thumbnail options. Why does Apple hide things like this? Anyway, thanks a lot.
Randy said: Tue, 24 October 2006 at 21:45
This is fantastic. I have been prompted a couple of times to requild the thumbnails. It’s something I need to do but the times it has ‘decided’ to do it have been totally inconvenient and inappropriate.
Thanks to this suggestion I can take control of my time! Thanks!
Matt said: Wed, 13 December 2006 at 13:41
Thanks so much. Several blind alleys looking for how to do this. I do like my Mac, and most of the software, but why they hide stuff like this I’ll never understand.
Trainwrecka said: Mon, 18 December 2006 at 04:24
This site rocks! I was searching google on how to rebuild my iPhoto cache and viola! here is Silver Mac. i have now linked you on my blog.
Carolyn Layton said: Tue, 16 January 2007 at 12:06
What is the advantage of rebuilding iPhoto cache?
I have about 10 folders in iPhoto and about 4000 pictures
blair said: Wed, 24 January 2007 at 18:50
thank you! the web needs more people like you. cheers!
nate said: Sat, 3 February 2007 at 02:35
OPTION-COMMAND clicking on iPhoto did NOT work for me. iPhoto 6.0.5. But SHIFT-OPTION-COMMAND clicking did.
Thanks for pointing us in the right direction though.
Ben said: Fri, 9 February 2007 at 19:30
Thank you so much! Why they don’t document this I’ll never know. Cheer mate!
Goobimama said: Sat, 24 February 2007 at 02:35
Thanks so much! This has saved so much of my time….
Anne said: Mon, 26 February 2007 at 21:29
Thank you so, so, so much!
MJ said: Wed, 11 April 2007 at 01:16
THANK YOU!!!
Kinsey said: Sun, 13 May 2007 at 03:26
I was working in iPhoto 6.0.6 and it prompted me “Caution would you like to rebuild your thumbnail cache?” so i click ok, it took about a minute, and when it was through … all my thumbs in my iphoto library are gone!!!! PLEASE HELP!!! When I double click on them, you can see them in the edit screen, but not in the library to scroll through them! How do I get them back?? It wouldn’t let me undo my action either! PLEASE HELP ME
Mike said: Sun, 13 May 2007 at 09:37
Try selecting “Rebuild all of the photos’ thumbnails” and see if it works that way.
Mauricio said: Sun, 24 June 2007 at 10:54
Is there a cache for iphoto in the library originally installed by the program because I opened my caches folder and i can`t find any iphoto related file. The same happens with application support, there is iWeb but not Iphoto. I tried to zap iPhoto and reinstalled again but neither of those files appear in my library
Thanks for feedback
Digital said: Thu, 28 June 2007 at 15:43
Thank you!!!
Fee said: Fri, 29 June 2007 at 05:50
Thank you so much for this. I’m hopefully that my iPhoto library might actually work now!
Steve said: Wed, 4 July 2007 at 23:28
I don’t like iPhoto. I love my apple iMac and eveerything else about it, but my 9000 photos are in a mess!! When I look on disc I have them in ‘data’, I haave two sets of originals and two sets of modified. I have some in the trash folder of iPhoto, but when I empty trash, they disappear from the library. I have loads of unknown ‘rolls’ on disc from when I first started using it and didn’t know to rename the roll. To start again will take me the best part of a week!
Is there an easy way to just reinstall iPhoto and start afresh cos I reckon I’m gonna have to before it gets any worse!
Ui Goldsberry said: Sun, 29 July 2007 at 08:20
Wonderful site. I have a thumbnail question. Whenever I make any changes to my original photos in iPhoto, I lose the thumbnail in my iPhoto library in my photos file. So, when I want to make a CD, or copy my photos onto a storage disc, the photos that I’ve changed, show up with a JPG document thumbnail. Is there any way I can assign a photo thumbnail to my changed pictures? It would make it much easier to locate the ones I want.
Thank you so much for this service. It is really incredible.
zach said: Fri, 19 October 2007 at 12:25
you are a rock star. so glad i spent only 15 minutes trying to figure it out unsuccessfully. APPLE - get a shortcut in the file menu for this!!!
Lisa Stefanoff said: Mon, 24 December 2007 at 10:42
When I followed the prompt to upgrade my thumbnails nothing happened even though I was warned that it would ‘take a while’. Then the next time I opened iPhoto (6.0.6) all my thumbnails were gone. I’ve tried the COMMAND + OPTION, found the rebuild box, ticked all the rebuild boxes, but still nothing is being rebuilt. Anyone have any advice? Thanks, LS
Joko Anwar said: Wed, 16 January 2008 at 14:07
Thank you!!!!
sophie said: Mon, 21 January 2008 at 13:00
I just want to know exactly what it means to rebuild my thumbnail cache. Don’t want to do any mistakes and delete all my pictures
Nicole said: Wed, 30 January 2008 at 05:37
Thank you SO much for this info. Why one can’t just type in “rebuild thumbnail cache” into the help files and get the same answer is BEYOND me.
Joevdburg said: Wed, 20 February 2008 at 16:12
OK, I need to chime in as well. This was a VERY helpful find. Much appreciated.
JV
Alex said: Sat, 1 March 2008 at 17:35
So did anyone figure out if this rebuilding of the thumbnail cache is actually worth it? I have about 2000 photos and a lot of them are RAW… should I do it? I definitely don’t want to lose my thumbnails… but I also don’t want the program to shut down on me or anything crazy… so basically:: does anyone have any advice for me?
Amanda said: Mon, 14 April 2008 at 00:47
Thank you so much!
Gast said: Tue, 20 May 2008 at 11:29
THANKS A LOT MAN!!! OVER THE YEARS I’VE TAKEN MORE THAN 6000 PICS AND I JUST COULDN’T GET THE DAMNED THUMBNAILS WORKING AFTER I ACCIDENTALLY ERASED THEM. YOU’RE A GENIOUS!!!!