Reducing the Lightroom Catalog size (significantly)

My Lightroom catalog contains something like 30k images at the moment, from 2007 when I first began to become more interested in photography (with my first DSLR, a Nikon D70) all the way up until today. The catalog size grew and grew and grew, all the way to 4.5GB. Backup and optimization where taking longer and longer.

So most recently, I went through a major cleanup and deleted about 2000 older images that actually never made the cut, but that I never rejected (market with the black X flag) immediately, either. Funny enough though, while deleting 2000 crappy photos freed a substantial amount of hard disk space, the catalog size didn’t change at all. What the heck?

So I looked into things a little more, and it turns out that what really blows up the catalog is the History – every single editing step is recorded in the catalog, taking up crazy amounts of disk space. I don’t know about you, but I really don’t need to retrace my editing steps once I’ve finalized these edits, so I just wanted to clear the entire edit history for the older folders in my library (I sort my photos by date).

WARNING: doing this will actually and really remove the edit history, as advertised. 🙂 So if you have information in there, placed by a plugin or whatever else, that may be useful to you (for example, when you last exported a photo), you will lose that information.

It’s not quite obvious how to zap the history for a large amount of photos, so here are the necessary steps:

  1. in the Library Grid view (press “G”), select all images (CTRL+A).
  2. If you’re using image stacks, make sure to do the double CTRL+S combo to first collapse, and then expand all stacks, then press CTRL+A again to really select all images. 😉
  3. Switch to the Develop module (press “D”)
  4. from the menu (that’s important), go to “Develop” and select “Clear History” (clicking on the little X in the left-hand History panel will only delete the history of the active image, that’s why you need to use the menu instead)
  5. Lightroom will now ask if you want to clear the history only for the active, or for all selected images (obviously, you want to clear it for all selected images)

After I zapped the history for my photos from 2007-2010 (I kept it for 2011-2013 for now) and optimizing the catalog, the catalog size was down a whopping 1.2GB, from 4.5GB to 3.3GB. Nice!



  1. My catalog is at 132,689 images and over 18GB for the catalog and preview file. I have wanted to get all of the wedding and event images into a separate catalog — maybe someday!


  2. I found that for the deleted images to affect the Catalog size you just need to do the Optimize thing. Even a restart doesn’t do it, only when optimizing. And i hadn’t done that in a long time because for some reason they moved that button to the File menu, while it used to be in Catalog Settings.

    Anyway, you make it sound like the History thing is related, but these are just two different things really. Personally don’t like deleting the History, because i like going back to see what i did, and it’s easier to compare the original by clicking on the first History item called ‘Import’ that would then be gone.

    The catalog cleaning up links to the deleted files was probably what cause most of the drop in size as it did for me. I don’t think cleaning up the History would make that much of a difference, so only do so if you want to.


    1. Maurice, I back up and optimize my catalog weekly, and optimization alone has an effect on the catalog size, but it is relatively small.

      Personally, I don’t see the point of keeping the edit history for photos that I made 8 years ago – your mileage may vary.


  3. Oh, and my preview catalog is 44GB. Would it be safe to dump that since I really don’t use LR to tone? I usually only use LR to tone things like weddings, portrait sessions, and other shoots requiring mass toning.


    1. Instead of deleting the entire previews folder, I’d suggest that you simply adjust the Catalog Settings / File Handling and set it to discard the 1:1 previews sooner (mine is set to 30 days, but one week and just one day are also available).

      Liked by 1 person

Thoughts? Let me hear them.

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s