Compress PDFs On Your Mac With Preview or an Automator Quick Action

When you scan in documents with your iPhone or other device you sometimes end up with files too large to store or send in an email. You can easily compress a PDF using the Preview app on your Mac. However, the default compression setting is too high for most uses. Learn how to customize the compression with your own quartz filter and then use it in Preview or turn it into a Quick Action using Automator for one-step PDF compression.

Comments: 20 Responses to “Compress PDFs On Your Mac With Preview or an Automator Quick Action”

    Dave Dickson
    3 months ago

    Gary, I think that I followed this verbatim, other than creating a copy of the original file. The new file is actually coming out larger than the original. Any idea why, or how I can correct it?

    3 months ago

    Dave: Perhaps the original was already pretty compressed? What was your original size and the resulting size? What compression setting did you use when making the Quartz Filter?

    John Carter
    3 months ago

    Fantastic! Thank you very much.
    I think you have convinced me now to start creating my own Quick Actions.

    Greg Turnbull
    3 months ago

    Mine went from 20MB to 22MB

    ??

    Marj Green
    3 months ago

    I have the same problem that Dave had. My file size came out larger. I took a 7.2mb pdf Guide for my treadmill; the size after running Export>Reduce PDF File Size Better came out to 8.8 mb. The quartz filter I added was as Image Compression>jpg>about 10 quality. Any clue what Dave & I are doing wrong??

    3 months ago

    Greg: What setting for the Quartz Filter? Were the images in the PDF already pretty compressed?

    3 months ago

    Marj: What do you mean by “10”? Do you mean about 10%? Or do you mean 10, as in all the way to the right? That would set the images to the maximum quality which isn’t what you want if you want to reduce file size.

    nick
    3 months ago

    hi Gary, this is timely. Just the other day I was struggling with the quality of a PDF with a lot of images. What has always been confusing to me that under the File menu in Preview you have a choice to: Export (PDF is one of the options). Export to PDF, and then under Print you can Print to PDF. And each of these choices have access to different options. Any particular reason for this menu structure? thanks

    3 months ago

    Nick: Well, printing is fundamentally different even if you customize it to be a PDF export. A lot of apps don’t have any PDF Export function, but you can print and save as PDF because that is part of macOS. Export offers more options than Export as PDF. I haven’t done a comprehensive look those two to see the differences. I assume one is just a quick way to do it and the other a little more involved.

    Narelle
    3 months ago

    After i do the Color Sync, Filters, +, Down arrow & Image compression = the file name dosent stay, and when i close CS, go back to my PDF, export, and there is no new filter? I am running 10.11.6

    3 months ago

    Narelle: Not sure why it won’t stay for you. Keep trying it to see if you can figure it out. Make sure the name stays there and you can see it in Color Sync before going any further.

    Janis
    3 months ago

    Gary I had the same results as Dave. I, too, followed instructions verbatim. Tried a couple different pdf files that were larger than I desired. One pdf. original was 13.5mb, results 16.2mb! Other pdf. original was 8.1mb, results same size this time of 8.1mb. To verify I’d created as instructed actually deleted and started over 3 times. Same results.

    3 months ago

    Janis: What compression setting did you use in your Quartz Filter? Did you try others? What was in the PDF? A 13.5MB PDF with 12 images was probably already well compressed, for instance.

    frank
    3 months ago

    Gary the compression settings reduce the file size for a PDF scanned from the iPhone PDF, just like you used in the video. However for other PDF’s, such as from a traditional scanner, it can increase the size multiple times e.g 5.2mb to 14.4mb for a scanned 32 page word document with no images..

    3 months ago

    frank: If your file is 5.2MB then it is probably pretty well compressed. So unless you set the Quartz Filter compression very low, you won’d get more savings and it will go the other way. 5.2MB for 32 pages is pretty good if you think about it. A single image is often that size, but 32 pages is a lot of area to digitize.

    cindy
    3 months ago

    Excellent! I just changed a 3.6 MB file to 1.2 MB. I would have liked to see the file in kilobytes but ……. You are a treasure. Thank you for the “How To’s”.

    Eric W.
    3 months ago

    Gary: I email PDFs (e.g. Proposals, Quotes, etc.) directly from Pages all the time to clients (Print (Command+P) > PDF (bottom/left) > Send in Mail). How can I have the compression automatically applied in this circumstance without first needing to save as a PDF?

    3 months ago

    Eric: Probably. I haven’t tried to build something, but you could probably make something by creating the Print Plugin type of document in Automator.

    lali
    2 weeks ago

    Actually I tested this tip as shown on the video, instead of reducing the file size, it increased from 124 KB to 130 KB. When I downloaded the file from a bank starement it showed 124 KB but the compressed file as suggested by the video it become 130 KB.It is not reducing the file size at all. I did not use any special compression; only used reduce file size was selected while compressing.I did not use automator since I am unfamiliar with creating one I need help on that.

    2 weeks ago

    lali: That can happen if the PDF is already compressed well enough to begin with. You are just recompressing it and will end up with a file about the same size, sometimes a little more, sometimes a little less. In that case, just toss the new copy you made and keep the original. A 124K file is pretty small so no need for this.

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