Why Your PDFs Are Too Big And How To Make Them Smaller

Hi, this is Gary with MacMost.com. Let me show you why the PDF files you create are probably too big, and how you can make them smaller. So, I often hear when people create PDFs from documents they're working on, that the PDFs are much larger than they think they should be. Maybe it's just text and a few images, and you end up with something that's several megabytes in size, and you really need something smaller, perhaps to submit it to an online system, or you just don't want that big of a PDF file to share around. Let me explain why this is probably happening. Now, this same thing could be happening in just about any document creation app, like Microsoft Word or Adobe InDesign, but I'm going to use Pages, something that every Mac user has easily available. So here I've got a Pages document. It's about 14 pages long, and it's just text. You could see it here in the folder. As a Pages document, it seems a little large for just text, 372K, but now let's export it as a PDF. That will allow you to send it to people, and they could view it even if they don't have Pages, and better still, they can just really view it. They're not getting the source document to be able to change it. It's basically a digital form of a printed piece of paper. So I'm going to go to File, and then Export to PDF. Then I'm not going to choose anything special here. I'm not going to worry about image quality, because there are no images in this. I'm simply going to Save, and I'm going to just save it here to this Examples folder. You can see I get this PDF, and the PDF is 105K. If I take a look at it by double-clicking on it and opening it up in the Preview app, you can see I get a perfectly fine PDF here. Since the text is actually included in the document, along with font information, I can actually zoom in as much as I want, and the text remains super smooth. So this works perfectly fine in creating a PDF, but the problems start when you add an image. I'm going to take this picture.jpg image here and add it. When I double-click on it to look at it in Preview, it's a very large, high-resolution image. You see, I can zoom in quite a ways and get a lot of detail here. That's why this image is 12 megs. It's not your typical photo, but nearly a 60-megapixel photo. I'm going to drag and drop it into the document here, and then I'm going to resize it, because I don't want it to be huge. I just want it to be a small image here off to the side, maybe taking up about half the width of the page. So now when I go to export this as a PDF, I do want to pay attention to image quality. I have Good, Better, and Best. Let me export this using each of these settings. So now you can see I've got three different PDF files here. As you may expect, the one that's saved with Best Quality is the largest. You can see how it's about the same size as this picture here, plus the PDF that's just text. So it's including the actual original image in this. And if I look at this document here, I can actually zoom in, and I can see that level of detail there. But chances are, when you're giving somebody a PDF, they're not zooming in like that. They're simply viewing the document like this, and all that extra resolution isn't really getting them anything except a larger file. Now the option of using Better when exporting is compressing things, and quite a bit. You can see it goes from 12.3 MB to 159 KB. If I look at this document, I can't really tell much of a difference here when just viewing the document normally. But of course, if I zoom in here, I can see I don't have nearly the resolution that I did before. But it looks fine when I'm just reading the document normally. And I get a much, much smaller file. And then the Good option is compressing it even more. So when I zoom in here, you can see the much lower quality. So as a basic rule, if you want to give somebody absolute fantastic image quality and you don't care about the size, use Best. If you want to compress things but still want the images to look decent if they zoom in just a little bit, then use Better. If you don't care about image quality, you just want the smallest size possible, then use Good. And say if you're just giving the document to somebody to proofread, then that might be a good reason to use Good. If you find these videos valuable, consider joining the more than 2,000 others that support MacMost at Patreon. You get exclusive content, course discounts, and more. You can read about it at macmost.com slash patreon. Now another factor is cropping. So right now I'm showing the entire image here. But typically, you may actually want to crop an image. If I double click on this image in Pages, for instance, I can zoom in like this. And you can clearly see the area that's going to be shown and the area outside that's going to be cropped. So if I want to zoom in just on the bird here like this and click Done, I get something that looks like this. Now what happens if I export this using the same three image options? Now you can see here, using Best, the file size is the same. So even though I have cropped out most of the image, you can see the PDF is including the entire image as is, but only showing the cropped area. When I look at Better, I actually get a larger size than when I did Better with the entire thing. What's probably happening there is it's compressing the image, but at the new size, and then cropping it. So you get the entire image at kind of a medium kind of compression, but you're only getting the benefit of seeing the middle portion of it, the portion that hasn't been cropped. And the same thing with Good. It's compressing the entire thing, but at a larger size, and then just showing you a cropped area. So it looks like there's a problem when using Pages and similar apps when you crop. It really is including the entire image, even though the user only gets to see a portion of it. So what's the fix for this? Well, the fix is to not give Pages the entire image in the first place. If you really want to create smaller PDFs, put smaller images into the document. So I'm going to open up this picture here in Preview. You could use any image editing app that you like. Preview is just something I know we all have. And I'm going to duplicate this, create another copy of it, and I'm going to call this picture cropped, and save it, and you can see how it saves another copy there. It's the same size, but what I'm going to do is I am going to, with the markup tools here on, I'm going to use the Rectangular Selection tool, and then select an area that's approximately the same size as our cropped area before in the document. So something like this, maybe. And then I'm going to crop it by going to Tools and Crop. But also, I want to have fewer pixels because remember, this is really high resolution. If you don't need that amount of high resolution in there, let's go to Tools and Adjust Size and see that even though I've cropped it in, this is such a high resolution image, it's still 3,000 pixels across. If you use a general rule of thumb that 300 pixels per inch or dots per inch is pretty high quality, and this is going to be at 4 inches wide on the page, that's still 1,200 pixels wide. But maybe I don't even need that high quality, maybe half of that is fine. So let's do like 600 pixels wide. And I'll have it scale proportionally, resample the image, and you can see that the resulting size is going to be less than 20% of the original. So it does that, and I can zoom in here and I can see, yeah, that's fine quality for what I want. And I will save. And now I can see here I've got the picture cropped, it's only 62K compared to the 12 megs of the original. So I'm going to drag and drop this into the document here, and I'm going to resize it to about the same size as the previous one, like that, and I'll take this previous one away. So now I've just got this one in here. Notice the Pages document, which is 12.5 megs. Now when I save, it's going to save it, and now it drops down to 412K. So I know I've got this new, smaller sized image in here, not the original. In fact, to do this even faster, bring up the right sidebar here, go to Image, there's a Replace button. So you can just go from image to image, click Replace, and select the replacement image, and have that one be slotted into that space, instead of dragging a new one in and deleting the old one. So now let's go through the exercise of exporting in all of the different PDF compression levels. Great, so now you can see, Best is 167K, Better, 135, and Good, 112. It looks like Best is using the original size of the file, whereas Better is compressing it a bit, and Good even more. Let's take a look at the quality here, and we can see the quality here of Best. We can see it's going to be a little less quality here in Better, but it still looks pretty good, and then Good is going to drop that quality level down quite a bit there. So you can see, I ended up with a much smaller file at the Better quality size than I did when I had just cropped it inside of Pages. So the real winner here is if you want to have the smallest PDFs you can to crop and export your images exactly as you want them before bringing them into Pages, or after you've already created the document and you decide you want to produce a smaller PDF from it to go through the images and create new versions of them and replace what you have in Pages with those new versions that are exactly the right level of quality and compression that you want. It's likely that the same technique will work in other apps where you're creating documents as well. Hope you found this useful. Thanks for watching.