How Much Space Do Lightroom Smart Previews Really Take Up?

Starting in Lightroom 5, Adobe released something called a Smart Preview. It’s basically a preview of your photo, that’s big enough to let you work on your photos even if the drive they’re on isn’t connected. Here’s a screenshot of the option in the Import dialog.


It’s a great option for people who like to stay mobile because they don’t always need to keep their external drives with them. So what’s the tradeoff? Why not build a Smart Preview for everything? Well, they take up space on your computer’s hard drive (or whatever drive has your Lightroom catalog on it). But how much space? Well, after running some tests, I’ve found that it’ll roughly take up anywhere from 2-5% of the actual photos themselves. So, for example. If you’re uploading 1 GB of photos and you choose the Smart Previews option, you’ll have a file called “YourCatalogName Smart Previews.LRData” that’s about 25-50 Mb in size.

How To Delete Smart Previews
A good practice to get in to is this. Let’s say you’re working on a photo shoot and you want access to work on it even if the drive the photos are on isn’t connected. Well, building Smart Previews would be a great option. But then let’s say you’re done working on that shoot after a few days and don’t need the Smart Previews anymore. Well, you can just go to the top menu (in the Library module) and go to Library > Previews > Discard Smart Previews.


Author: Matt Kloskowski

Matt is the full-time Director of Education for Kelby Media Group and a Tampa-based photographer. He's the Editor-in-Chief of Lightroom Magazine, the lead instructor on the Adobe Photoshop Lightroom LIVE Seminar Tour and author of several best-selling Photoshop books. Matt also hosts the world's top Lightroom blog,, where he's built up a massive library of Lightroom videos, presets and tips. In addition to teaching Photoshop, Lightroom and photography seminars around the world, he's an instructor at Photoshop World and one of the full-time staff writers for Photoshop User Magazine.

Share This Post On
468 ad


  1. Hi,

    Yesterday I have been generating Smart Previews with Lightroom 5.6 on my MacBook Pro running OS X 10.9.3 in order to save space on my SSD. My RAW’s are stored on an external drive.

    Everythings works fine. When I disconnect the external drive, only the smart previews are used.

    What I noticed is that of my 200GB+ RAW files the Smart Preview file remains about 300MB in size. I only have one catalog and when searching I only find one Smart Preview file, the one in the same folder as the catalog file. When I look at my catalog configuration I see that calculated Smart Preview file size is much lager than the 300MB.

    Do you have any idea what’s going on here?

    With kind regards, Dennis

    Post a Reply
  2. I’m testing this whole Smart preview thing, but one thing I came across..
    I have around 400GB on images, so if I would make a smart preview of all of them, it will result in a file of 20gig or something > perfect for a laptop with SSD! Right?

    I tried this with 20 pictures, everything works out well, but then, if I permanently delete the 20 pictures from my hard drive (external), the smart preview file stays the same size.
    So my guess is that the real pictures are deleted, but not the smart previews… so in time, the smart preview file will become bigger and bigger, since everything stays on it.

    A solution to this might be that before you delete pictures, you always delete the smart previews first, but that’s kind of annoying…
    So my question is: is there a better solution to this problem?


    Post a Reply
    • Meanwhile, I already found the answer:
      If you “optimize catalog” then the smart previews of deleted pictures are removed :)

      Post a Reply
  3. Is there any way to selectively delete Smart Previews? I have this problem of creeping disk storage for Smart Previews, but sometimes need one shoot and don’t need others any more.

    Post a Reply
    • Yep. Select the photo and go to the Library > Previews > Delete option.

      Post a Reply
  4. Thanks for this tip, Matt! Since LR 5 came out I’ve wondered how big the file space would be and how to get rid of them! My 15 inch Macbook Pro retina has a 250 GB ssd in it. So I only have my programs installed on it. I use a 1tb G drive to store my vacation photos and photowalk photos. So, I would save my photos on the G drive and then wait to get home before processing them on my Desktop. So my question is if the Smart Previews are stored on the Laptop how do I get the changes I’ve made to them to my desktop? As you can see I’m not a great computer wizard! :-)



    Post a Reply
    • Hey Dennis. Your changes get synced back up with your photos whenever you actually attach the hard drive that the photos are.
      Hope that helps.

      Post a Reply
      • Ahhh! The light comes on. See, I told you I wasn’t a computer dude! :-)

        Thanks Matt, appreciate the info!


        Post a Reply
      • OK, I’m clearly less of a “computer dude” than Dennis. What I don’t understand about your answer to him is …

        His program is on his laptop; his photos on his external drive; and, his concern is how to get his smart previews onto his DESKtop.
        He assumed his smart previews are on his LAPTOP (not his external hard drive). Am I correct in understanding that to be wrong?
        Do the smart previews attach themselves to the photo (like an xml file)? Is that what you meant by it would automatically sync (cuz the necessary file/info stays with the photo, not on his laptop where the program is)?
        I’m just wanting to be sure I’m understanding since this is a question I also needed an answer to!
        Thank you!

        Post a Reply


  1. A Short Guide to Using Smart Previews in Lightroom 5 | Echoes of Eden - […] Smart Previews are tiny. I exported the original Raw files contained this small Catalog (16 in total) and the …
  2. The Andrew S Gibson photography blog » Blog Archive A Short Guide to Using Smart Previews in Lightroom 5 » The Andrew S Gibson photography blog - […] Smart Previews are tiny. I exported the original Raw files contained this small Catalog (16 in total) and the …

Submit a Comment

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>