A free PDF compressor is essentially a tool that you can use to reduce the size of a PDF file. It is also called a PDF size compressor or PDF optimizer and is available both online and as installation software. There are also mobile apps that can capably compress PDFs on the go, which is useful when sharing files from your mobile devices.
To offer some background, PDF compression involves complex algorithms for text, images, and other types of content. It also removes unwanted content to make the file size smaller. The front-end interface for most of these apps is simple enough, but unless you know the tool and how well it can execute these algorithms, it's hard to evaluate the product.
This article tries to zero in on the best PDF compressor online and offline by looking at various options and how they work to compress files. So without any further ado, let's get started!
Part 1: People Always Ask…
Q1: How do I compress a PDF for high quality?
The higher the compression level, the lower the output quality of the content in your PDF. Therefore, if you require high-quality output from your PDF size compressor, it's best to choose the lowest compression level available. This approach can be used when you have images that need to be printed in hard copy or displayed on a large screen since their resolutions will be kept as close to the original as possible. In HiPDF and PDFelement, you can try the Low or Medium setting to see which is more suitable for your specific use.
Q2: Is it safe to use a free PDF compressor?
Absolutely! Just make sure that the software you download is from a reliable source or has been checked for malware. Check to see if there's a padlock symbol on the website to make sure the site is secure. Additionally, you can look for online reviews of the product before you download it. If you're searching for an open source PDF compressor, make sure it is a stable version.
Part 2: Top Online and Offline PDF Compressor Solutions
Name |
Feature Highlights |
Trial Version Available? |
Pricing for Premium Version |
|
Online PDF Compressor |
Wondershare HiPDF | ● All basic and advanced PDF tasks ● Powerful compression engine ● Highly user-friendly interface |
$6/month | |
FreePDFConverter | ● Good compression quality ● Clean UI and easy navigation through the site ● Handles small to medium-sized files well |
Free | ||
Smallpdf | ● Professional PDF utility ● Simple interface ● Several PDF task modules are available |
$9/year | ||
AvePDF | ● Advanced compression method ● Good for integrating into products via API ● Easy enough for new users to try |
Free | ||
Offline PDF Compressor |
Wondershare PDFelement | ● Comprehensive PDF features - Standard and Pro ● Cross-platform availability ● Affordable solution for individuals, businesses, and students/teachers |
$6.66/month | |
Adobe Acrobat | ● Extensive feature list ● Widespread use ● Advanced and professional PDF utility |
14.99/month |
Section 1: Best PDF Compressor Online
1. Wondershare HiPDF Compressor
One of the most versatile and best PDF compressor online solutions is HiPDF from Wondershare, the makers of Filmora, PDFelement, and several other blockbuster products. This online PDF toolkit comprises several modules for various basic and advanced PDF tasks such as editing, file conversion, PDF security, file and page management, forms management, optical character recognition (OCR), batch processes, and more. It is a highly rated app that can be used free of cost with some limitations on the maximum number of pages or the size of your document, and upgrading to an affordable plan will fully unlock the tool's immense capabilities.
How to Use HiPDF Free PDF Compressor
Step 1 Head over to the HiPDF Compress PDF web page and upload your PDF file - use the button provided or drag-and-drop from its folder location
Step 2 On the next page, set the compression level based on the purpose of using the output file (high compression is suitable for web viewing)
Step 3 Directly download the file to a local folder or cloud service, or click Continue to perform other actions on the file, such as editing, protecting, or converting to another format
Pros
Easy operations
Free for individual files
No registration required
Cons
Batch process is only available with a subscription
No advanced compression settings
Wondering about the best ways to compress your PDF? Watch the video below to find the best ways to compress your PDF file offline.
2. FreePDFConvert PDF Compressor
Essentially a file conversion utility for PDF and other document workflows, FreePDFConvert has now grown to a large repository of useful tools for file compression, protection, and general PDF management. It is a robust and secure platform that encrypts all documents that are uploaded or downloaded so your files are safe. The site is easy to use and you can import PDF files via their URLs or from cloud storage.
How to Use FreePDFConvert
Step 1 In the Online PDF Compressor page of the main website, click Choose PDF File to upload a document
Step 2 On the next page, you'll see a preview of your file and two free compression options on the right - Better Quality and Better Compression - choose one and click Compress
Step 3 On the final page, there are options to download locally, save to cloud or perform more actions on the processed file - select Download and save the file to your computer
Pros
Simple and attractive interface
Good compression quality
Convenient upload and download methods
Cons
Only two free compression options
Compression level is not that high
3. Smallpdf Compressor
Smallpdf is a powerful and versatile PDF compressor with a vast array of PDF tools. The compression quality is excellent, although the free tool only allows basic compression. Nevertheless, it offers a desktop PDF solution in addition to the online version, similar to HiPDF from Wondershare. In a pinch, it's a fast tool to work with and offers several useful PDF utilities to help manage PDF workflows.
How to Use SmallPDF Compressor Online Free
Step 1 Upload your PDF file to the appropriate Smallpdf URL for file compression
Step 2 Once uploaded, select the Basic compression level as the free option and click Compress
Step 3 On the final page, you can download, share, or continue to other actions
Pros
Simple compression process
Good compression quality
Access to premium PDF tools
Cons
Only one compression level is free (Basic)
Multiple files require a paid plan
4. AvePDF Compressor
The AvePDF compressor tool is a powerful utility that leverages the mixed raster content (MRC) compression method that gives you almost lossless compression for images. As such, it's a useful tool for compression PDFs that contain high-resolution images that need to be compressed for sharing but also need to maintain the quality of the images in question.
How to Use AvePDF Compressor Online
Step 1 Go to the Hyper-compress PDF page of AvePDF and upload your file by dropping it there
Step 2 Choose a compression level from the four options on the next screen
Step 3 Click Compress and wait for the process to be completed
Step 4 Choose one of the download options or proceed to another task with the same processed file
Pros
Uses MRC compression technology to maximize image quality at high compression
Versatile utility that can be embedded into another website as a widget
Excellent compression level and quality
Cons
No control over compression settings
Intended primarily for professionals
Section 2: Best PDF Compressor Online
5. Wondershare PDFelement
Wondershare PDFelement - PDF Editor is a fast-rising star in the PDF constellation that's appealing for many reasons: it is available for multiple platforms (Mac, Win, iOS, etc.), it has a dedicated cloud platform (Wondershare Document Cloud), it is more affordable and lighter than most premium PDF editors, and it offers the full gamut of PDF tools required by any professional, businessperson, or student. As versatile as the software is, it's even easier to use because of the clean UI and clear navigational elements (icons, labeling, layouts, etc.) A highly awarded PDF product, PDFelement is one of the top emerging PDF editors in the market today.
Wondershare PDFelement Pro DC
Simplify your Workflow with the Document Cloud for PDFelement.

How to Use the PDFelement PDF Compressor
Step 1 Launch PDFelement on your PC or Mac and drop a PDF file into the interface to open it
Step 2 Click the Tool option at the top and then Compress PDF in the ribbon toolbar beneath it
Step 3 Choose the compression level you need and hit Apply
Step 4 Save the compressed file with a different name using File → Save As
Pros
Robust PDF utility with excellent compression quality
Cross-platform availability with cloud storage access integrated
Slick UI with a high usability quotient for beginners and professionals
More affordable than most premium PDF solutions
Cons
Watermarks are applied in the free version
Not available for Linux users
6. Adobe Acrobat
Another versatile PDF compressor with advanced capabilities is the ubiquitous Adobe Acrobat. While the software itself is considered a little clunky and cluttered by many users, the majority of users vouch for Acrobat's versatility and width of features. The compression tool is of special note because it gives the user a lot of freedom to control compression quality and other parameters.
How to Use the Adobe Acrobat PDF Compressor Feature
Step 1 Open the Acrobat Optimize PDF utility from the application's Tool section by clicking Tool → Dropdown arrow below the Optimize PDF icon → Open
Step 2 Next, import the PDF file to be optimized by selecting it in the Explorer dialog and clicking Open
Step 3 Select Reduce File Size in the ribbon toolbar menu above the document
Step 4 Set the compatibility for the file in terms of the PDF version - use Retain Existing to keep the current format support
Step 5 Once processed, assign a new name to the file and save it to the desired folder
Pros
Well-known PDF compressor that millions of users are familiar with
Advanced optimization options to control image downsampling levels, color schemes, and more
Robust utility that works well with heavy PDF workflows
Cons
The UI is a little complicated, especially for first-time users
The product is expensive and usually bundled with other Creative Cloud products
Might be too advanced for processing basic PDF tasks such as editing, conversion, security, file management, etc.
In Parting
PDF compression is usually an intricate process, but it doesn't have to be that way for you, as a user. Leveraging the wide platform support of tools such as HiPDF and PDFelement, you can boost your productivity and output in a meaningful way using the simplified user experience that these products provide.
Wondershare's philosophy of making PDF simple is exemplified in these star PDF products for online and offline use. Enhanced file security, extensive features, high affordability, and seamless cross-platform transitioning are topped off by a user-friendly interface and a zero learning curve to get you started on the path to becoming adept at handling PDF workflows.