Reducing PDF Size: PC & Mobile Solutions to Compress


Not everyone is familiar with systems to reduce the size of PDFs, an issue that we will address in the next few lines. We will focus attention on software available both on smartphones and on one’s PC, while also taking a look at online platforms, which are often a solution for those who lack storage space on their device.

The use of documents, whether paper or digital, requires considerable storage space, either physical or virtual. In order for you to optimize the management of your documents, you should perform compression, a simple operation, but one that should be evaluated in the best possible way. One of the most widely used formats is definitely PDF, which has now become a standard for storing documents in common or business use.

If, on the other hand, you want to know how to turn a Photo into PDF you will find everything in our article: How to turn a Photo into PDF.

Reduce PDF size: why do it?

Before examining what are the software to reduce the size of PDF files, it is appropriate to devote a few lines to what are the motivations that may prompt those who work and study to use such tools.

Every person has different needs, and although compressing the size of PDFs may seem like a trivial task, it actually allows different problems to be solved in different areas. Let’s look at the benefits and reasons in taking advantage of a program to reduce the size of PDFs.

Optimized storage

When compressing a PDF file, one must necessarily interact with it, providing the end user with an objective analysis of the document. This process makes it possible to rename the file and be able to store it in a way that is functional to the referenced activity.

Space reduction

It is not hard to imagine what the main motivation is in reducing the size of a PDF, in fact, more and more users need such a feature in order not to quickly fill the storage memory of their devices.

Good compression software can achieve a file reduction of up to90 percent, a significant percentage if you need to work with numerous digital documents.

File Management

Additional reason in taking advantage of PDF size reduction software lies in improved file management. Most programs create a PDF file by naming it differently, a condition that allows you to figure out in seconds which file to delete and which to keep.

Being able to simplify file management is essential, especially in the business environment, where time planning is an integral part of making money.

Conversion of documents

Many people convert their Word, Excel, PowerPoint and similar files into PDF files, this in many cases results in extremely large digital documents that take a significant toll on device memory.

Those who periodically convert files from other formats need to reduce the size of PDFs; in some cases files can exceed several gigabytes, affecting system performance in no small measure as well.

Public Entities Request

There is no shadow of a doubt that PDF compression software is particularly used when there is a need to send documents in this format to public agencies. Reference servers, especially municipal servers, have low performance and can receive digital files with a size not exceeding a certain threshold.

This element puts users in a position to reduce the size of the PDF and then be able to send it without receiving an error message.

E-mail limitations

Not only are Public Entities constrained to the size of files received, but also a great many digital providers do not allow emails and attachments larger than a few megabytes.

Reducing the PDF in this case is essential in order to forward the attachment(s).

Faster Upload

The moment you reduce the size of one or more PDF documents you can obviously get faster uploads. Uploading a 10 MB file to an external server is completely different than uploading a 1 MB file. In this case you benefit from significantly reduced time and limited network resources, also affecting your mobile data tariff plan less in case you were charging from a smartphone.

Limited cloud space

More and more people prefer to save their PDF files to acloud service, whether it is free or paid. As much as the cloud plans you choose may consist of a good number of gigabytes, compressing PDF files significantly helps to speed up the download/upload and not fill up the virtual memory in a short time.

Reduce PDF size: Websites

The process of reducing the size of a PDF file can be initiated in several ways. In the next few lines we will focus on the three most effective and fastest methods with which to interact: websites, applications and dedicated software. Let’s start with online PDF file compression sites.


One of the most beloved websites for compressing PDF files is definitely iLovePDF, a digital platform that also allows you to: merge, split and convert this type of format.

To use the platform you need to go to the official iLovePDF page and click on the Compress PDF section, or press here. Once you have accessed the page you can decide to register or not, but it is not absolutely mandatory if you only need to reduce the PDF file.

To start the reduction procedure, simply drag the file within the middle section, or click on Select PDF file and select it within your device.

The webpage not only allows you to upload PDF files from your device’s internal storage, but also to be able to do so directly from Google Drive and Dropbox, two widely used cloud platforms.

PDF24 Tools

Alternative solution, but one that is no match for the more famous iLovePDF is PDF24 Tools. This website features the same operation, but adds a very interesting feature: it has no upload limit.

Several online platforms do not allow files larger than 10 MB to be uploaded, whereas PDF24 is particularly versatile. In addition to dragging and dropping the file inside the compression window and choosing to upload from the device’s internal memory, this website also allows you to download the Desktop version of the software.

But it is in the quality of compressed file adjustment that it stands as an excellent solution. Usually this feature is present only on dedicated software, whereas in this case you will also be able to choose the quality of reduction most useful for your purposes.


One of the most preformant websites for reducing the size of PDFs is SmallPDF. As can be deduced from the name of the platform, the main purpose of the digital software is to minimize the size of the uploaded PDF.

The website points out that file compression can achieve as much as 70 percent reduction, while still following RGPD guidelines and TLS encryption.

To access the service there is no need to register, in fact, simply launch the official page and click on the Choose File option, located in the center of the page.

Dragging the file directly to the center of the dedicated section may also be fine to start the compression process.

The platform also provides choice of compression level and quick sharing with other applications. Definitely one of the most interesting websites for those who want to get extremely reduced PDFs without losing too much text quality.


When you need an all-in-one website for document management, whether these are PDFs or other formats, Online2PDF is almost always the most effective option. The platform handles both PDF compression and several other functions, including: viewing, protection, and conversion.

Although there are file limitations of 100 MB to upload and a maximum of 20 files, the PDF reduction process is fast and very effective.

Just go to the official web page and scroll down to the section devoted to editing files. Clicking first on Compression and then on Select Files will allow you to upload and proceed to compression by pressing on Convert.

The platform guarantees that uploaded files will not be saved on their server, thus, there is also a marked focus on cybersecurity and personal data protection.


Digital portal in which to perform PDF file compression is Soda PDF Online. Website capable of ensuring good compression by acting mainly on three main aspects: bits, information and versatility.

In fact, one of the strengths of this platform lies in its ability to shrink PDF files using fewer bits than the original document. This feature also extends to what information is contained in the file; no data will be lost, since the software algorithm will decide which areas can be most compressed.

A document with many images, undergoing considerable compression, could offer poor quality thanks to the algorithm this does not happen, always benefiting from a readable and sharp file.

Versatility comes from the ability to use the software both online and on your smartphone or Desktop.


The desire to minimize the size of a PDF file sometimes collides with the unavailability of the file itself from a third-party site. In order for this issue to be curbed, it is advisable to take advantage of platforms that allow the URL link to be inserted directly. One of the most famous is PDF2GO, with which one can directly enter the URL of the PDF to be compressed, as well as use Dropbox and Google Drive to perform the same operation.

Interesting function of the website lies in its customization of compression type. In fact, you can choose from three reduction modes: basic, strong and preset. The latter is especially suitable for those who need to choose a certain quality of the file and the images within it.

To start the compression procedure simply click on Choose a file and upload it, otherwise opt to copy and paste the URL. By clicking on Start, a button located at the bottom, the reduction procedure can be started.

PDF Candy

We also chose to include PDF Candy among the most interesting websites for reducing the size of PDFs because it is one of the most comprehensive and easy to use.

In addition to the drag-and-drop feature, which allows you to directly drop the file into the platform and start compression, PDF Candy also offers many other interesting features. First of all, it compresses files safely, using an automatic system that deletes them two hours after upload.

A two-level compression is also added to this feature; in fact, the website ensures that the user can choose whether to make a marked or light reduction, pandering to his or her needs.

You can also add PDF files from your Dropbox or Google Drive profile.

Reduce PDF size: from Android and iOS

Using websites capable of compressing PDF files is not always the best solution, in moti cases you might run into a server error and not even be able to access the platform. To free yourself from this issue, you can opt to download a dedicated application for your smartphone, a solution that allows you to always have the program at hand. However, what are the best Android and iOS apps for this function?

Compress PDF – Android and iOS

This software’s handling of PDF compression is extremely accurate and reliable. As unquestionable as its effectiveness is, it is worth noting that the reduction process is extremely long, usually around an hour’s time.

Even when uploading a very light file, the timelines remain the same; this is due not to the quality of the software but to the marketing strategy aimed at inducing users to choose the paid version, which costs about 11 euros. This turns out to be very quick.

You can download the app from both the Play Store and the App Store for free. The program itself will ask you whether you want to take advantage of the free version or prefer to go for the subscription version. For Apple’s home systems, the application can also be installed on the iPad.

iLovePDF – Android and iOS

As anticipated in the previous lines, iLovePDF is available for most platforms, whether they are fixed or mobile. The application features very few sections, but with which you can compress any PDF without any problem. Once you have uploaded the PDF file to be reduced, simply choose the level of compression: low, recommended, and extreme.

Once you have chosen the mode best suited to your needs, you can press the Compress button and wait for the compression process. Selecting the three vertical dots, positioned to the side, will take you to the settings, these allow you to decide whether to rename, open or view the converted PDF file. Available in both the Play Store and the App Store.

PDF Small – Android

PDF Small’s application is certainly not as popular as its online version, but it offers the same performance and excellent compression of PDF files. It is currently a software available only in the Play Store and allows for the best management of three levels of reduction: low quality, high quality, and recommended quality.

Among its strengths is that it is lightweight; in fact, it does not require major resources on one’s smartphone. It also adds to that feature a compression of up to 90 percent of selected PDFs, a value to be reckoned with especially for those who use large files to upload within the cloud space.

SmallPDF – Android

Although the name of this application is very similar to the one recommended above, it offers features that differ substantially. In addition to having the same goal of compressing PDF files, SmallPDF also allows documents to be scanned, combined, converted, and edited within the software itself.

From a compression function standpoint, it has two levels: strong and basic, the former capable of compressing PDF files up to 75 percent, while the basic level is limited to 40 percent.

Graphically, the software offers interesting cues that may be appreciated by those who are not just looking for a program that edits and reduces files of this format. Again, this is available only for Android operating systems.

PDFOptim – Android – iOS

Software that can especially help those who need to compress PDF files to really tiny sizes is PDFOptim. The most recent version allows the size of PDFs to be reduced even below 100 Kb, providing virtually all the benefits that such an application should possess.

Although it is available for both Android and iOS, the latter version costs about 3 euros, thus affecting one’s budget.

Features that have made this software famous include real-time comparison through preview. In fact, it will be possible to compare, side by side with the document, the two generated PDF files. While this may seem like a minor feature, it is actually essential in understanding what quality is achieved after size reduction.

PDF Reader – Android

Not everyone is aware that the software built into Android operating systems, PDF Reader, also allows you to perform PDF file compression.

As much as the main purpose of this application is to view PDF files and in case forward them, you can also use it to manage documents and reduce, edit and convert their size.

In case your Android smartphone does not have this application preinstalled, you can download it from the Play Store, or by clicking here.

To begin the file compression process, you should press on the tools button and choose the dedicated function.

PDF Utility – Android

Versatile application that allows you to reduce the size of the PDF and does not require a performing smartphone to work at its best is PDF Utility.

The Android version features all those useful features for extracting images, saving them to PNG or JPG, and compressing PDF files as desired.

To consider it a software aimed only at the compression of PDF documents would be limiting, this application is much more and can be used without any fear even for work-related areas.

It can be downloaded from the Play Store in very few seconds, and the app is lightweight and free of annoying banner ads.

All PDF – Android

As a final application we want to emphasize the compression qualities of All PDF. This software can help in the management of PDF files by binding both the reading and editing steps. In fact, you will be able to split, compress and merge PDF documents with great ease whenever you want.

The Android version has been excellently optimized not only for smartphones, but also for tablets and PC app emulators.

It is certainly not the aesthetically best application, but in essence it does not fail to provide excellent compressions and to do so extremely quickly, as well as free of technical errors within the reduced text.

Reduce PDF size: from Windows and macOS

Third way to reduce the size of PDFs is to directly download a Desktop version. Those who have to compress several files on a daily basis will find in an already installed and offline software the best solution to speed up operations, having everything under control with mouse and keyboard. Let’s look at the best software to install on Windows and macOS operating systems.

Acrobat – Windows

The quintessential software developed for the purpose of viewing PDF files, Adobe Acrobat, also allows files of this format to be compressed.

In order for you to use the built-in feature you will just need to click on File, top left, and select Save as Other. From here, select the PDF item with reduced size and proceed to compression. To download the software simply click here.

Free PDF Compressor – Windows

Those who need more advanced PDF size reduction software can turn to Free PDF Compressor, a program that can also let the user choose the number of dpi of the image to be compressed. The sizes specifically to be chosen are 72, 150, and 300 dpi.

You can download Free PDF Compressor completely free of charge and take advantage of a very lightweight installation file; the program is portable.

ShrinkIT – iOS

Owners of an iOS operating system will no longer be able to do without ShrinkIT, a solution that enables the optimal management of their PDF files with compressions of very few seconds.

You can proceed to download the software at this link, following the manically explained wizard on the home page. Definitely an excellent program, even considering an installation file size of 1 MB.

Reduce PDF size: features to look for

The significant number of software available to reduce the size of a PDF file in many cases can be confusing to those who have never approached such a tool before. Let’s try to understand what elements should be evaluated before downloading one rather than the other.

Ease of use

An excellent program is one that can guarantee maximum results in the shortest possible time. These elements are tied, of course, to ease of use, which in many cases differs depending on the method of PDF file input.

A platform equipped with Drag and Drop is definitely the best choice for speeding up compression operations; this can be used even by those starting this type of tool for the first time.

Custom sizes

The function of compressing a PDF document already in itself is particularly useful, as we have pointed out several times before, but at the time when you have special needs it is appropriate to rely on a platform that can allow a good level of customization.

Not all software dedicated to PDF size reduction allows you to choose a different compression; many of them arbitrarily define what are the best parameters. The dpi are in many cases decisive because they ensure that you get a PDF file precisely the size and quality you want, without overstepping the limits of e-mail or Public Entity Web sites.


Uploading a large PDF file and then waiting several minutes for conversion is definitely not pleasant. In many cases this operation depends on the platform used, some of which offer almost immediate compression, while others take up to an hour. As much as in many cases you might think that a website or application that takes longer offers more quality, this is actually not the case.

In fact, the quality of the PDF file is defined before starting the reduction process, therefore, the timing to finish the compression depends purely on the computing power of the server used by the software.

Choosing fast software reduces processing time and allows you to better optimize your day. Those who work with PDF files on a daily basis might also think about a paid solution, getting surely excellent results.

Compression quality

One of the most common problems when compressing a PDF file lies in the resulting graphic resolution, which is particularly poor. Unfortunately, the moment you reduce the size of the document, the software removes all those surface elements that can weigh down the file.

Usually it is the images that suffer the greatest reduction in quality, while text is almost always visible even at very low resolutions.

A program capable of offering optimal compression quality is definitely the choice to make, even at the expense of a slower and more cumbersome upload.

Additional formats

People are often led to think that a site to reduce the size of PDFs is developed only to compress files of this format. In fact, by choosing the right software, you will be able to reduce the size of other file types and also convert them to PDF.

Certainly the layout and some features of the document may not be perfectly aligned, but for those who need to accomplish this task quickly, it can be a viable solution. Imperfections usually do not occur in paid versions.


Starting a compression program without too many functions allows only the size reduction operation to be accomplished. This approach may be more than sufficient for the private sector, but SMEs and companies may find it limiting.

Several programs, whose features we have already highlighted, offer functions that can be used during work activities. PDF file editing, merge and split functions can be functional to speed up one’s work.

Italian language

It is by no means a constraint to choose software in Italian, but there is no doubt that it can be indispensable for two types of users: those who do not know English and those who need assistance in using the program.

A platform in Italian is also accessible to those who are not very familiar with information technology, facilitating older users without foreign language skills. This reasoning also applies to those who want to read the internal guides to the compression site, a condition only possible on an Italian and fully translated platform.

Free buy

Although a plethora of completely free applications can be downloaded, it must be pointed out that the best ones are paid.

All users who do not need to perform day-to-day operations with their PDF files can rely on free software without any fear, but those who need to manage awork task with this type of file will feel the need to opt for a paid solution.

In the above list we have included both free and premium programs, trying to satisfy all types of users.

Reducing PDF size: mistakes to avoid

Having assessed the parameters closest to one’s needs, it is smart to use the software in a way that can offer their maximum potential. In many cases, PDF size reduction software is employed incorrectly, resulting in a result far from what was hoped for. Let’s see what mistakes can be encountered when using such a platform, trying to avoid them as best we can.

Marker inside

The free nature of so much PDF compression software induces developers to advertise. Such propaganda occurs within the compressed PDF file, through a small marker on the digital page.

As you can easily infer, displaying a marker in a professional file is definitely not the best you can hope for. This can be remedied by using third-party software capable of deleting it, but this would entail further loss of time.

The best solution is to pay attention to platforms that do not include such an element within the compressed file, or to rely on paid services, which in any case do not present such a nuisance.

Incorrect Layout

By the time you load a PDF file inside the compression tool, no matter how optimized it may be, it can hardly define a perfect layout. By uploading an A4 file, there are no particular problems in compressing the PDF perfectly, but uploading A2, A3 or even larger formats may present minor layout problems.

Some software performs better than others on this issue, so beware of software that does not support the desired format. Unfortunately, in most cases compatible formats are not specified, you have to experiment with multiple solutions initially. We recommend compressing the PDF file and paying attention to the layout, perhaps comparing it with the original one.

Distortion of margins

Reducing the size of PDFs forces several software programs to lower the dpi number, affecting the overall resolution. Although you may not notice edge distortions by looking at the document with a standard zoom, as you bring the image closer you will notice a distortion of the letters.

Such a mistake should be avoided at all costs if you do not want to get bad prints, in which the readings will be covered by small ink specks.

Checking, thanks to the preview, what the final result will look like allows you to eliminate this harmful problem. Some websites also report the points most prone to distortion.

Low resolution

The desire to reduce a PDF file as much as possible causes so many people to choose the lowest resolution. Although for textual documents this action may also be justifiable, it becomes a red-pencil error the moment images are present within the file.

Too low a resolution, such as 36 dpi, will completely grainy the images, making them almost completely unusable once printed.

Internet network not fast

Those with a poor Internet connection, both download and upload, will find it complicated to take advantage of an online service for PDF size reduction. Unfortunately, uploading a large PDF file online requires good network speed, otherwise the time will be stretched considerably.

Those without a high-performance network will find smartphone applications and software for Windows and macOS ideal solutions.


Reducing the size of PDFs can be very useful, as we have analyzed in the previous paragraphs, in many cases you can improve document management and most importantly save several gigabytes on your hard disk or cloud system. The choice between one software and another depends on one’s purposes, whether these are aimed at the private or professional sphere.