Compress PDF files online for free

You can compress a PDF for free using Adobe’s online PDF resizer tools. Simply use the  Select a file  button on the page above to navigate to the file you want to compress. Alternatively, you can drag and drop your file into the box with the dotted outline. You can choose to compress your file in one of three compression levels—high, medium, or low, depending on your requirements.

Adobe is the best online tool to compress PDF files without compromising quality. Choosing a low compression level reduces the file size to approximately 1MB while retaining the highest quality settings. For even smaller files, you can select medium compression to reduce your PDF size further. With ISO/IEC 27001 certification, you can rest assured that your files are handled with security and integrity.

Try a 7-day free trial of Adobe Acrobat Pro to test out the precise optimisation tools.

Adobe online tools can compress PDF files up to 2GB using the PDF compression tool—meaning even the biggest documents can be brought down to size. You can easily compress a PDF to 500 KB or even lower.

Some email platforms and file storage systems require documents to be less than 1MB. In this instance, you might need to compress your files.

Here’s how to compress a PDF to 1MB or lower for free:

1. Go to the   Adobe Compressor   above.
2. Choose the PDF you want to compress, then  Select   your file or  Drag and Drop   it into the drop zone.
3. Choose your level of compression, then select  Compress  to reduce the PDF file size to under 1MB.
4. Once that’s done, simply  Download   your compressed PDF from the webpage.

Our PDF compressor tool will show you how large your file is after compression. Check the estimated file size before you click Compress when browsing compression level options. On Windows, you can also check file sizes by right-clicking on the file in your folder and selecting Properties. On Mac, you can do this by control-clicking the file and selecting Get Info.

To compress a PDF to 100KB, use the Acrobat PDF compressor online tool or reduce the file size in Acrobat itself. For the second option, open the app, click ‘Optimise PDF’ in the Tools bar and choose the file you want to compress. Then, simply click ‘Reduce file size’, then select the size and version quality you want.

You can follow the same process to compress a PDF to 500KB.

It’s quick and easy to compress and reduce a PDF file size on a Mac. Just look at the step-by-step instructions below:

1. Open the Preview app. This is Apple’s default image and PDF viewer, so you’ll already have this installed.
2. Once you’re in, open up your PDF.
3. Click File, then choose Export. Make sure  not  to press Export as PDF.
4. Select the  Quartz Filter  menu, which should pop up on your screen.
5. Finally, click Reduce file size. You’re all set.

If you need to upload a large PDF to an online platform—for example, for a school or work project—you may need to make it smaller by reducing the file size. You can do this easily, and for free, using Adobe’s top-rated PDF compressor online. Remember to check the maximum file size for the platform you need to upload your PDF to so you can compress it to the correct size.

You can resize a PDF by using Adobe Acrobat’s free online compression tool. Compressing a PDF simplifies its data to reduce the size, and if you’re using a low compression level, it won’t largely affect the quality. This makes PDFs easier to share, upload, and store.

Compressing your PDF can reduce the quality of images or video in extreme circumstances. However, your overall document quality, fonts, and styles will not be affected. That means your document layout and design shouldn’t be impacted by the PDF Compressor.

Yes, Adobe offers this functionality. Simply drag and drop your files into our online merger tool, and it will handle the rest. The tool can merge various file types, including JPG/JPEG, PNG, Word, and Excel files, once converted to PDF.

Yes, you can easily upload files and drop files into our compression tool from your mobile device. You can do this via your browser or the Adobe Acrobat Reader mobile app, compatible with both iOS and Android.

Yes, you can use our PDF editor to make changes to your PDF with advanced editing features. Even with a compressed file, you can add text, change fonts, add comments, highlights, and much more.

Yes, Adobe online tools are free to use. They enable you to convert files from one format to another or compress file sizes. To use the tools, go to one of the pages—for example, PDF to Word or Excel to PDF—and follow the simple instructions before downloading your converted or compressed file. Want to share the file? You’ll need to sign up for a free Adobe account.

As the creator of the PDF, Adobe Acrobat is generally considered the best PDF compressor for its balance between compression and quality. Our online tool reduces file size while maintaining document integrity, making it suitable for printing and professional sharing.

The best app to compress PDFs on a mobile will be different for everyone. Adobe’s PDF compressor tool is available on both iOS and Android devices, with a user-friendly interface that allows efficient compression. If you want to open and edit your PDF on iPhone and Android, that’s also possible.

Adobe is often cited as the fastest and most efficient PDF compression service. With just a few clicks, you can easily compress your PDFs and reduce file size to store, send, and upload. Fast results and excellent quality.

Online PDF compressor tools are most suitable for quick, one-off tasks. They’re available across most devices and are easy to use. However, they can’t function without a stable internet connection, and there may be a limit to the file size you can compress.

In contrast, offline PDF compressor software can handle very large or numerous files without restrictions. Files are also downloaded to your device, which offers better security. This also takes up storage space, and you’re limited to using that device.

Generally, yes, but this depends on the provider’s policies. It’s important to choose a PDF compressor that prioritises security and privacy. At Adobe, we take data privacy very seriously, and this is reflected in our online tools. We offer advanced security, including password protection and encryption, ensuring the safety of your documents.

PDF compression lowers image resolution (known as downsampling) and removes redundant data to shrink a PDF file size. This can sometimes result in blurry, lower-quality, or pixelated images. If you’re adding an image to a PDF and want to compress the file, ensure you select low or medium compression options to preserve its quality.

Some of the most common issues of PDF compression tools include:

• Loss of image quality.
• Failure to reduce file size
• File corruption and data loss.
• Slow processing times.
• File size restrictions.

To avoid any mishaps, always keep a copy of the original PDF file before compression.

To choose the most efficient PDF compression service, look for advanced features that will suit your professional needs. These include compression quality control, optimisation features, batch processing, security and privacy, and compatibility. Adobe is the industry standard for comprehensive, high-quality optimisation, allowing you to compress your PDF files anytime, anywhere.

Yes, there’s a significant difference between lossless and lossy PDF compression. Lossless compression reduces file size without removing any data, while lossy compression permanently deletes redundant data to achieve smaller file sizes.

Discover more about lossy vs lossless compression and when to use them.

Yes, you can compress PDF files with Microsoft Word using the following steps:

1. Open Microsoft Word, click File > Open, and choose your PDF file.
2. Word will convert the PDF into an editable document. Formatting may change here.
3. Click File > Export (or Save As on Mac) > Create PDF/XPS.
4. Select the Minimum size (publishing online) option.
5. Name the PDF, then click Publish to save the newly compressed file to your computer.

Yes, even the best PDF compression sites have limitations on file size—usually up to 20MB. With Adobe’s online tool, you can compress PDF files up to 2 GB.

The best settings for PDF compression depend on whether you’re prioritising image quality, file size reduction, or a bit of both. Here are the recommended options based on your needs and preferences.

• High compression. High compression drastically lowers image resolution. This is most suitable for text-heavy documents where image quality isn’t as important.
• Medium compression. Offers a balance of reduction and quality. This keeps text sharp and images clear while moderately compressing the file.
• Low compression. Choose low compression for minimal image compression. This reduces the PDF file size slightly while maintaining image quality for printing.