How to Compress PDF Online [Online PDF Size Reducer Review]

Seeking tools to free compress PDF online? You've got to the right place. In this guide, we're introducing easy and free PDF compressor online tools. Then you can compress your PDF files online directly instead of downloading and installing a program on your computer, which is more efficiently and convenient. By the way, please focus on information safety when using an online tool.

Part 1. How to Reduce PDF Size Offline [Recommended]

PDF Compressor(Windows) is a delicately designed PDF compressor with a small size. This tool enables users to customize compression settings to achieve better results and maintain content quality. It is capable of reducing the size of large PDFs, often exceeding 30MB, to a significantly smaller range, typically between 1 and 3MB, resulting in a compression ratio of approximately 10%.

Key Features

• Fast compression speed.
• A slider to control the compression level.
• Compress PDFs in bulk.
• Compress locked PDF files.
• ...

How to Use

Part 2. How to Reduce PDF Size Online [Online PDF Compressor Review]

How to perform free online PDF compression? In this part, we have tested the top 10 online PDF size reducers. Read and check which one suits your needs most.

#1 www.ilovepdf.com

www.ilovepdf.com is currently one of the most popular online PDF size reducers. This website serves as a collection of online PDF tools, allowing you to organize, optimize, and convert your PDF files.

Pros

• No file size limit.
• Fast compression speed.
• Compression in bulk allowed even in the free version.
• Upload PDFs from local/Google Drive/Dropbox.
• Save the compressed PDFs to local/Google Drive/Dropbox or generate a shareable link.

Cons

• Limited to a maximum of 3 files per task for the free version (for Premium version the limit is 10 files per task).

How to Use

Step 1. Upload PDF Files: Click the "Select PDF files" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Choose your preferred compression level and hit the "Compress PDF" button.

Step 3. Download the Compressed Files: The website will automatically start the downloading process after the files get compressed.

#2 www.adobe.com

Adobe Acrobat is a highly acclaimed office software, and in addition to its offline applications, Adobe also offers a range of online PDF tools. Below is a brief introduction to Adobe's online PDF compression tool:

Pros

• Reliable website.
• No file size limit.
• Stable compression speed.
• Allow users to preview the compressed file.

Cons

• Compression in batch only available in Acrobat Pro version (Adobe offers a 7-day free trial).
• Can't upload PDF from Google Drive/Dropbox.
• Can't save the compressed PDF to Google Drive/Dropbox; instead, you can generate a shareable link.

How to Use

Step 1. Upload PDF Files: Click the "Select a file" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Choose your preferred compression level and hit the "Compress" button.

Step 3. Download the Compressed Files: Click the "Download" button to start downloading the compressed file.

#3 www.pdf2go.com

Similar to the websites introduced above, www.pdf2go.com is another website that offers numerous PDF functionalities. Through this website's PDF compressor tool, you can easily achieve compression of your PDF files. Here is a brief introduction to this tool:

Pros

• No file size limit.
• Fast compression speed.
• Additionally allow users to control the DPI of images; allow users to grayscale images and text or remove images to achieve further compression.
• Compression in bulk allowed even in the free version.
• Upload PDFs from local/Google Drive/Dropbox/a URL.
• Save the compressed PDFs to local/Google Drive/Dropbox or generate a shareable QR code.

Cons

• Limited to a maximum of 2 files per task for the free version.

How to Use

Step 1. Upload PDF Files: Click the "Choose File" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Choose your preferred compression level and hit the "START" button.

Step 3. Download the Compressed Files: Click the "Download" button to start downloading the compressed file.

#4 smallpdf.com

smallpdf.com is a website that offers a collection of various online PDF tools. With its user-friendly and intuitive design, this website can significantly enhance your office productivity. Here is a brief overview of this website:

Pros

• No file size limit.
• Fast compression speed.
• Allow users to preview the compressed file.
• Export your compressed PDF as a Word/Excel/PowerPoint/Image document.
• Upload PDF from local/Google Drive/Dropbox/your Smallpdf account.
• Save the compressed PDF to local/Google Drive/Dropbox/your Smallpdf account.

Cons

• Adjusting compression level is only available to Smallpdf Pro users.
• Batch processing is only available to Smallpdf Pro users.

How to Use

Step 1. Upload PDF Files: Click the "CHOOSE FILES" button or directly drag & drop your files to the window to upload. And the compression will automatically begin.

Step 2. Download the Compressed Files: Click the "Download" button to start downloading the compressed file. You can also choose to save the compressed PDF to your Google Drive/Dropbox/Smallpdf account.

#5 tools.pdf24.org

tools.pdf24.org is a website similar to smallpdf.com. In comparison to other websites, this platform does not impose any restrictions on the file size or the number of files you can compress. Here is a brief introduction to this website:

Pros

• No file size/amount limit.
• Fast compression speed.
• Allow users to control the DPI, quality, and color of images (you can choose to grayscale them).
• Upload PDFs from local/Google Drive/Dropbox.
• Save the compressed PDFs to local/Google Drive or send them via Email.
• Allow users to merge/password-protect/split the compressed files.

Cons

• Users can't choose the compression level.

How to Use

Step 1. Upload PDF Files: Click the "Choose files" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Customize your compression details and hit the "Compress" button.

Step 3. Download the Compressed Files: Click the "Download" button to start downloading the compressed file. You can also choose to save the compressed PDF to your Google Drive/Dropbox account or send the files via Email.

#6 www.compress2go.com

www.compress2go.com is a website specifically designed for file compression. On this platform, you can not only compress PDF files but also reduce the size of videos and images, and create ZIP compressed files. Here is a brief overview of this website:

Pros

• Compression in bulk (≤ 10 files) allowed even in the free version.
• Upload PDFs from local/Google Drive/Dropbox.
• Save the compressed PDFs to local/Google Drive or generate a QR code for scanning.
• Additionally allow users to control the DPI parameters of images (6 modes: Prepress, Ebook, Printer, Normal, Minimum, and Insane) and grayscale images for further compression.

Cons

• Processing of large files (≥ 100MB) is only available to Premium users.
• For the free version, the maximum processing time is only 30 minutes.

How to Use

Step 1. Upload PDF Files: Click the "Choose File" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Customize your compression details and hit the "START" button.

Step 3. Download the Compressed Files: Click the "Download" button to start downloading the compressed file. You can also save them to your Dropbox/Google Drive account or generate a QR code for sharing.

#7 www.freepdfconvert.com

www.freepdfconvert.com is a website similar to smallpdf.com. Here is a brief overview of this website:

Pros

• Upload PDF from local/Google Drive/Dropbox.
• Save the compressed PDF to local/Google Drive.
• Allow users to preview the compressed file.

Cons

• Compression in batch only available to Premium users.
• Users need to wait for 1 hour or sign up to compress the next file.
• Customizing further compression details is only available to Premium users.

How to Use

Step 1. Upload PDF Files: Click the "Choose PDF file" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Customize your compression details and hit the "Compress" button.

Step 3. Download the Compressed Files: Click the "Download" button to start downloading the compressed file.

Read more:

What Are the Best PDF Compressor? [10 Offline & Online Tools Introduced]

How to Compress PDF to 200 KB? The Road to 200 KB or Less

#8 www.sodapdf.com

www.sodapdf.com is a website similar to smallpdf.com. Here is a brief overview of this website:

Pros

• Batch processing available even in the free version.
• Upload PDF from local/Google Drive/Dropbox.
• Save the compressed PDF to local/Google Drive.

Cons

• The server is not stable enough.
• Adjusting compression level is only available to Premium users.

How to Use

Step 1. Upload PDF Files: Click the "CHOOSE FILE" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Customize your compression details and hit the "COMPRESS FILE" button.

Step 3. Download the Compressed Files: The downloading process will start automatically. If not, click the "DOWNLOAD FILE" button to start downloading.

#9 pdfcompressor.com

pdfcompressor.com is a straightforward website that offers batch processing capabilities. In addition to PDF compression, this website supports various other operations on PDF files. Here's a brief description of this website:

Pros

• The design is very user-friendly.
• Batch processing (≤ 20 files) available.
• No file size limit.
• All uploaded files will be deleted after 1 hour.

Cons

• Ads included.
• Can't upload/save PDF from/to cloud accounts.
• Users can't choose the compression level or customize the compression details.

How to Use

Step 1. Upload PDF Files: Click the "UPLOAD FILES" button or directly drag & drop your files to the window to upload. The compression will automatically start.

Step 2. Download the Compressed Files: Click the "DOWNLOAD ALL" button to start downloading.

#10 www.sejda.com

www.sejda.com is a website similar to smallpdf.com. Here is a brief overview of this website:

Pros

• Allow users to preview the compressed file.
• Allow users to control the resolution and the quality of images; allow users to grayscale images or discard multimedia files to achieve further compression.
• Edit your PDF online as you prefer after you compress it.
• Upload PDF from local/Google Drive/Dropbox/OneDrive/URL.
• Save the compressed PDF to local/Google Drive/Dropbox/OneDrive, or share them via Email or a link.
• Files will be automatically deleted after 2 hours.

Cons

• Batch processing only available to Premium users.
• Free document processing for files with a maximum of 200 pages or 100 MB, with a limit of 3 tasks per hour.

How to Use

Step 1. Upload PDF Files: Click the "Upload PDF files" button or directly drag & drop your files to the window to upload.

Step 2. Set Compression Preferences: Hit the "More options" button to customize your compression details and hit the "Compress PDF" button.

Step 3. Download the Compressed Files: Click the "Download" button to start downloading.

Conclusion

The online PDF compression tools offer you the flexibility and convenience to manage and share your PDF documents. Then you can reduce your file size without downloading or installing any software. However, you still need to think highly of your privacy security, and do not use public networks to compress your important PDFs.

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