When sharing a PDF file via email or keeping it in deject storage, it makes sense to keep the file as small every bit possible and then y'all don't waste space. On a Mac, you can use the congenital-in Preview app to resize PDFs, which is user-friendly.
Still, this process isn't perfect as it drops the file quality significantly. We'll testify you how to reduce a PDF'south file size without losing quality on a Mac.
How to Resize PDFs in Preview on Mac
It'southward easy to lower the size of a PDF using Preview. To practise so, just double-click a PDF in Finder to open it in Preview. In one case it's loaded, select File > Consign from the carte du jour bar at the top of the screen. In the resulting window, open the Quartz Filter dropdown box and select Reduce File Size before exporting the file, which will make it smaller.
While this provides a lower file size for the PDF, the problem with this method is that information technology drastically reduces the quality of the file. If your PDF becomes so blurry that is illegible, that isn't a suitable solution.
Thankfully, you can tweak some files on your Mac to strike a meliorate balance between quality and file size. However, this requires disabling an important security protection on modern versions of macOS.
Disabling SIP to Tweak PDF Export Quality
Starting with OS X El Capitan in 2015, Apple introduced Organization Integrity Protection (SIP). This increases the security of your Mac by restricting access to sensitive folders on your device. Unfortunately, you need access to the protected /System folder to perform this PDF tweak.
If you're comfortable with information technology, y'all can disable Organization Integrity Protection to go on with the following steps. If you do this, make sure to enable SIP over again as soon as yous're washed in order to proceed your Mac safe. You should also avoid downloading any untrusted software while you accept SIP turned off.
In case you lot don't desire to go through these steps, in that location are easier ways to reduce a PDF's file size without losing quality. Web tools are your all-time pick; attempt a free service like SmallPDF to reduce your PDF's file size without downloading anything.
How to Reduce PDF File Size on a Mac Without Losing Quality
To tweak the necessary arrangement files after disabling SIP, first open Finder. Select Go > Go to Folder from the menu bar, and so enter the location /Organization/Library/Filters.
The contents of the resulting folder control the options available in the Quartz Filter dropdown mentioned earlier. You should see ane called Reduce File Size.qfilter. Copy this and paste information technology to your desktop or some other convenient location.
To give yourself multiple PDF compression options, create multiple copies of the Reduce File Size.qfilter file. By changing the beneath values differently for each ane and saving them all separately, yous tin have access to various compression levels from the same carte.
Editing the PDF Quality File
Now, right-click on the duplicated file you lot just created. Choose Open up With > TextEdit, or whatever your preferred text editor is. It opens as an XML file, which is a mutual format for saving program options in a way that both humans and machines can read and sympathise.
Inside this file, look for the Pinch Quality line, which is inside <fundamental> tags. You can press Cmd + F to search for it, if needed. Past default, the value below this line, in <existent> tags, is gear up to 0.0. However, yous tin fix this to whatever value between -1 (highest compression, lowest quality) and 1 (least compression, best quality).
Yous may need to modify this value a few times to detect the right residue of quality and file size for yous. Try 0.5 for medium-level compression—you tin adjust it later if it doesn't seem right. If yous're making multiple files for diverse levels of compression, try 0.75 for a higher-quality file.
Nevertheless within the XML file, the side by side field you lot should cheque is ImageSizeMax. By default, this is prepare to 512, only you can change information technology to increase the final size afterward pinch. Endeavour setting this to 1684 for medium-quality compression (resulting in A4-size paper at 144DPI), and 3508 for loftier-quality pinch (equivalent to A4 paper at 300DPI).
Finally, wait for the Name field at the lesser of the file. Alter this to something clear, as the name will announced in the Quartz Filter dropdown box when you're done. If you're making two new files, you could apply Reduce File Size Amend for the medium-quality i and Reduce File Size All-time for the high-quality option.
Adding the New PDF Export Options to Preview
Save each file when you're washed. Rename the files in Finder to match the names you gave them in the XML, and so copy and paste them back into /System/Library/Filters where you got the original file from. If this doesn't piece of work, make sure y'all've disabled SIP, as you lot can't move files into this folder when information technology's active.
Now, when you use the Export card in Preview, you'll see the new options for pinch in your Quartz Filter dropdown bill of fare. Employ them to create a smaller PDF that doesn't drop every bit much in quality equally the default.
If you lot don't like how it looks, or the file size is still too big, endeavor playing with the values a bit until you get them right. Remember to plow SIP back on once you're satisfied with your new export options.
Compress Mac PDFs Without Losing Quality
Now you know how to reduce the file size of a PDF in macOS without making it completely blurry. Disabling SIP is an intensive pace, so you might non want to exercise all this if you only need to resize PDFs occasionally. But if y'all use the selection in Finder all the time, having the better-quality options right in the same menu is handy.
Don't forget that there'south a lot more you lot can do with PDFs on your Mac!
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