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.
▶ You can also watch this video at YouTube.
▶ Watch more videos about related subjects: Automator (50 videos), PDF (18 videos).
▶ You can also watch this video at YouTube.
▶ Watch more videos about related subjects: Automator (50 videos), PDF (18 videos).
Want to know more about how to use Automator on your Mac?Video Transcript
Hi this is Gary with MacMost.com. Today let me show you several methods of compressing PDF files on your Mac.
MacMost is brought to you thanks to a great group of supporters. Go to MacMost.com/patreon. There you can read more about it. Join us and get exclusive content.
You don't need anything special to be able to compress PDF files on your Mac. You can simply open them up in Preview and there's a special way to export them that compresses the images inside them. However the image compression settings aren't the greatest and it takes several steps. I'll show you how to build something in Automator that could do it quickly and also allow you to customize the compression.
So here I've got a sample PDF on my desktop. I can open it up and you can see it's just a sample electric bill. I scanned it in using my iPhone. The file size is a little bit bigger than I like. I'm going to do Command i to get information and see that it's 6.8 MB. It can definitely be smaller. So let's go and open it up in Preview by simply double clicking it. All you need to do to compress this is go to File and then Export. Not export as PDF. Not Save but Export. You'll get an option here for Quartz Filter. So you want to make sure you selected PDF as the Format and Quartz Filter has Reduce File Size by Default as a filter.
So now when I save it out I'm going to save it with another file name. I'll hit Save and let's look at that file. Do Command i and I'll see that it's 55KB. That's quite a size reduction. But if I look at it I can see the quality is pretty bad now. So it compressed it a little bit too much. Now those quartz filters are things that you can create. For that you need to use an app called ColorSync Utility. It comes with your Mac so just Search in Spotlight for ColorSync Utility and go to Filters. Here you'll see the filters that you saw there when you were exporting from Preview.
So let's add our own. I'll hit the Plus button here and I have one called Reduce PDF File Size Better. Then I'm going to click here and I'm going to go to Image Effects Component and Image Compression. Then I'm going to set Image Compression to be JPEG and set the Quality to something better than this middle. I'm going to go somewhere between halfway and all the way. So about ¾, about 75%. That should give us some decent compression without getting rid of quality. So now that should be Saved automatically. So I'll Quit ColorSync Utility and I will open up the original PDF again. I'll go to File, Export and I'm going to select Quartz Filter and instead of Reduce File Size I will look for mine that I just created, Reduce PDF File Size Better. Then I will Save it out using another file name. So a third version of the file.
Then I will go and get information on that and see that it's 1.1 MB. So quite a significant savings over the 6.8 for the original file. But when I look at it the quality is pretty good. It actually looks almost just as good as the original quality.
So next let's run Automator and I'm going to create a Quick Action in Automator. I'm going to add the ability to do these filters right here so I don't have to go into Preview. I'm going to create a Quick Action that will apply one of these filters without having to go into Preview. So I'm going to set this as Workflow receives current and it says automatic. I'm going to go and change it to Pdf file. Then I'm going to say Just in the Finder. Then I'm going to search over here for quartz and you can see I've got Apply Quartz Filter to PDF document. So that's the one I want. I'm going to drag it into here.
Then it's going to say, oh this is going to change the file so do you want to do a copy. You know what? I'm not going to do that for this but you can do that if you want to save the original and then have a copy. I'm going to just Not Add that make a copy. Then I'm going to choose a filter and I'm going to select the one we created. I could choose Reduce File Size. The original one but I'm going to do the one we made. Now I'm going to Save this and just name it Compress PDF and save it as a Quick Action.
Now that it's saved as a Quick Action I can access it many different ways. One of those is to Control click on the File and then go to Quick Actions and I should see it there. I'm going to select it and it is automatically going to apply that. You saw briefly there was a little gear up there saying it was working. Now if I get information on this original file you can see it's 1.1 MB. It actually changed the file right there in place. It's also easy to get to if you're here in the Finder in a regular window and you can select the file and you can see these Quick Actions here. I can click on More and do Compress PDF.
I can also customize if I'm using this a lot. I can go to the Finder here and I can move Compress PDF up to the top here. You can see that puts it in the first slot. So now all I have to do is select File and then Compress PDF right here in the Finder and it does it for me.
Notice when I created that Quartz filter there were other options. I could have had convert PDF to black and white. I could have also created multiple filters to use in different situations. So if I'm scanning something that has a lot of images in it and I want it to be compressed but still keep some good image quality I could choose one filter. If I want to compress them and it's not as important and it's mostly just black and white text I could select another filter.
In Automator in addition to doing Quick Actions you can make an application so you can just have it drag and drop onto an application. You can also do it as a folder action so any PDF that you put into a specific folder automatically gets compressed.
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?
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?
Fantastic! Thank you very much.
I think you have convinced me now to start creating my own Quick Actions.
Mine went from 20MB to 22MB
??
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??
Greg: What setting for the Quartz Filter? Were the images in the PDF already pretty compressed?
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.
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
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.
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
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.
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.
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.
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..
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.
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".
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?
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.
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.
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.