PDFs are one of the most flexible and reliable file types for sharing documents on the web and across devices.
Unlike Word documents, they don't risk formatting issues, and while images may fix this issue, they don’t always allow you to select text or embed links like PDFs can. PDFs have one major flaw however, and that’s their size. An unoptimized PDF can easily be near or over 20 MB, which causes many problems itself if not properly managed.
There are quite a few drawbacks to having an unoptimized PDF, one being the inability to send the PDF via email when the PDF files are too large. Today's email clients have been seeing larger and larger attachment size limits, but that doesn't mean you should or even can send a 25 MB file.
There are a couple of factors at play, some being the encoding of your email and its attachments when sent, the others are size limit for the recipient, and more. Based on current popular email client's limits and the added size from encoding, you should seek to send attachments no larger than 7 MB.
Even then, the smaller the PDF the better when considering a reasonable amount of quality.
You never know if the person you're sending the email to has a smaller limit than most, which is often the case with corporate email systems. Additionally, larger files can result in longer download times which frustrates recipients, especially if they're downloading the PDF on a mobile device.
If you're distributing an eBook or whitepaper for marketing or sales purposes, you'll suffer from unoptimized PDFs as well.
In this case, the PDF could result in:
There is a plethora of negative consequences associated with unoptimized PDFs which at best waste your time, but worse, negatively impact your bottom line.
That's why it's so crucial to optimize every PDF you send and/or distribute.
When optimizing PDFs, there are three factors to consider:
In most instances you'll be optimizing for search and for file size, but if it's just a document destined for a client or colleague's email, then PDF SEO is unnecessary. We'll break down PDF optimization by each use case to make things simple.
First and foremost, you need to ensure your PDF is optimized for reading on mobile devices. This applies to all PDFs whether they are destined for an email or are published to the web to attract new customers. We live in a mobile-first world where email, search, and even purchasing decisions are made on smartphones and tablets. That's why you need to be optimizing your PDF for mobile before anything else.
There are two major components to mobile PDF optimization. First, is the size of the file, and second is the formatting of the PDF itself.
Let's start with optimizing PDF file size:
Establishing a good baseline for file size on mobile devices starts with understanding their download speeds.
According to Lifewire, 4G speeds can range anywhere from 7 Mbps to 16 Mbps, while 3G speeds are just 4 Mbps.
Let's use the slower 3G speeds for our purposes since we want our PDF to serve well to as many users as possible.
Next, we need to look at how long we have before a person gives up on loading the PDF. Using web page abandonment data, we can safely assume that 3 seconds is the maximum PDF load time that a user is willing to tolerate on a mobile device.
Based on that data, we can assume that a mobile-friendly PDF should be 8 MB or less.
If your server is running slowly, then you’ll also need to adjust for that and keep the file size small enough to deliver that PDF in less than 3 seconds.
Contrary to what many believe, page length isn't the most important factor to PDF size. A one-page PDF could be much larger than a 60-page PDF, depending on the PDF content optimization.
Luckily ActivePDF offers a simple, yet powerful and highly-customizable .NET API solution that enables you to compress PDF files automatically called Compressor so you don’t have to stress by doing it manually.
Here are some of the tips and tricks you can use to reduce PDF file size:
Usually your PDF software will contain multiple options when creating it as well to help cut down on file size. There may even be an optimize PDF tool that can assist with much of this for you, in addition to automatically choosing the best format for size.
Another important factor for mobile PDF friendliness will be its format.
Depending on the devices size and the app they use to read your PDF, they may have trouble viewing it properly. We recommend keeping most text and elements aligned left, and using a font that's large enough to be viewed on mobile devices with ease.
Multiple subheadings and strategic use of bold text will help too.
If you've already optimized your PDF for mobile, chances are you won't need to do much to optimize for email. As we mentioned earlier, you’ll want to keep files to a size of 7 Mbps or lower to make delivery across the most common email clients possible.
Ensure that your PDF is compatible with a PDF viewer as this will minimize any formatting and compatibility issues your recipient may have. ActivePDF's browser-based PDF viewer and editor, Reader Plus, is free to try and available here:
Optimizing your PDF for the web is where things can get tricky. You'll want to start by applying all the measures found in the mobile optimization section above. However, there are a couple of additional things you'll want to consider such as SEO and linearizing (also known as fast web view).
If you're not familiar with linearizing, it's simply setting up a PDF so that it loads incrementally instead of all at once. This allows the PDF to load one page or even part of a page at a time, letting the reader begin reading while the rest of the PDF loads. Linearization is a must in a time when viewer's attention spans are shorter than ever, so that should be your first step towards optimizing a PDF for the web. After that, you'll want to consider optimizing your PDF for search engines and for the best SEO rankings.
PDFs are indexed by Google and thanks to the large amount of content within them, often rank quite well. You'll want to optimize your PDF for SEO to earn the best chance at getting on the front page.
Here are some tips for optimizing your PDF for Google, Bing, Yahoo, and other search sites:
PDF Optimization is important for both email, where it could be necessary to deliver the PDF to recipients, and for web, where SEO and linearization will result in better performance across the board.
Regardless whether the PDF is sent via email or via the web, you'll want to optimize for mobile to maximize compatibility and convenience for readers.
That's why we recommend optimizing your PDF by:
Compressor is the developer API you need to compress text, images, and objects to reduce the size of PDF files. Eliminating the time-intensive work of performing manual compression tasks, Compressor eases the daily challenge of working with large-sized files.
