Easily Compress PDF Files Online

Try an easy-to-use online solution for reducing the size of your PDF and forget about complications
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File extension .pdf
Internet media type application/pdf
Description: PDF is the Portable Document Format developed by Adobe Systems. It was invented to streamline the process of sharing and viewing files independent of any software, OS or hardware. Individuals can use PDFs wherever and whenever they want on any device. PDF files can contain textual and visual data as well as links, buttons and more. PDFs can be also password protected and edited with special programs.
Technical Details: Graphics are represented in PDF very similarly to that of PostScript. PDF graphics use a device-independent Cartesian coordinate system which describes the surface of a page. The page description uses a matrix to scale, rotate, or skew graphical elements. The graphics state is a collection of graphical parameters that may be changed, saved, and restored by a page description.
Developed by ISO
Initial Release: 15 June 1993
Useful links: https://acrobat.adobe.com/us/en/acrobat/about-adobe-pdf.html

How-to guide

How to reduce the size of a PDF document online

  1. In order to compress a PDF, open AltoCompressPDF.com in your web browser.
  2. Click Choose File to add a document from your hard drive.
  3. Click a cloud storage service icon to add a PDF stored online.
  4. Wait for your upload to finish, then click Compress Now!
  5. Click the Trash icon in case you’ve uploaded the wrong document.
  6. Wait while your new PDF is being generated, then choose what you want to do with it.
  7. Click Work on your PDF to redact it or share it with other users.
  8. Click Download Now to download the resulting PDF back to your device.

The Ultimate Features Comparison Chart

Due to the high level of competition on the web, choosing the best application can be challenging — especially if you don’t accurately compare it with the alternative options. Our benchmark table will help you easily pinpoint your preferred tool to Compress PDF. Get to know the forward features of AltoCompress.

Smallpdf Adobe
Split PDF
Merge PDF
Combine & Reorder
Extract Pages
Compress PDF
Rotate PDF
No software downloads
Cloud storage Unlimited No info No info
Price Free Free 7-Day Trial paid Free 7-Day Trial paid
Encryption and security
Support 24/7/365 No info
No ads

Customer Reviews — Trusted by great people



Excellent solution! If the size of your PDF document is too big, reduce it with just a few clicks. It solves the memory shortage problem. Plus it’s so quick!



What I like best about the AltoPDF tool is that no registration is required. Creating an account is one of those things that makes me wanna leave the website.



That’s awesome! I can compress my PDF files from any device, even when I’m in a taxi or on a buss, or walking on the street. It take up memory cause no installations are needed.

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How To Compress a PDF File

Using this service everyone can decrease the size of the PDF file in several simple steps. Just open the website and compress the document from any device.

How to Compress PDF Files Online

This website was created so you could compress files quickly and easily. Its ease of use and compression speed makes it one of the top solutions for decreasing file formats online. The best thing is the quality of images and text included in the document will always remain the same. The solution doesn’t take up any memory on your device and it never needs to access your personal information. This website is cross-platform and is available from any internet-connected device. 

Here’s how you can easily compress the file size online:

  1. Open the web-based service. Browse for a file in your device’s internal storage or in the cloud. Import it to AltoCompressPDF.
  2. Once the template is available, compress it.
  3. Save the document with the newly-deceased file size to your storage.
  4. Repeat this operation for as many files as you need.

Usage of an online platform saves you time, money and space. And the location of all of the tools in the cloud eliminates the need for installation. We offer the highest security measures and the possibility to compress the size of as many documents as you need. The platform has a lot of additional online options available for free use. You can reduce files without any payments, registrations or trial periods. For those who want to use this tool on the go, a lite mobile app is available.

BackgroundHow to Compress PDF Files Online


There are several ways to compress pdf docs. The most popular are offline software and online tools. While software requires time and costs to install, online platforms like AltoCompressPDF help you avoid such problems and is very convenient, as it is available on the go from any device. Take three steps: upload the document, click the orange button and download the downsized one to your computer.