Best Online PDF Compressor: Compress PDF to 100 KB for Free

2017-07-26 21:18:00 / Posted by Megan Charles to PDF Follow @ Megan

Transferring a large PDF file is usually limited since it will occupy a lot of resource of network when you send it by email. So we need to reduce PDF file size. When I searched it on Google, I found that there were so many people asked for best online free PDF compressor to compress a PDF file to 100 KB. Though there are numerous online PDF compressors, quite few can compress a PDF file to 100 KB for free. After countless testing on different PDF compressors, here is the final answer.

Best Online PDF Compressor: Compress PDF to 100 KB for Free

Online2pdf Compressor is the only one online PDF compressor that can compress my 11.8MB-PDF file to 98KB. Its powerful compression capability results from different compression modes and settings to downsize a PDF as much as possible. In addition, this online PDF compressor provides a brief interface, you can click “Select File” button to add your PDF file or just add by drag-n-drop. Furthermore, PDF Compression allows users to select several files at once (by pressing the Ctrl-Key).

  1. Go to the online2pdf.
  2. Upload PDF files that you want to compress by clicking “Select Files”
  3. Tweak the compression preferences. If your PDF file is super large, choose lower quality settings as much as possible to get your PDFs under 100KB. Try different compression modes to decide which one fits your online pdf compressor
  4. Click “Convert” to compress PDF. After the compression, the compressed PDF will be automatically downloaded to your computer.


  • The maximum file size this online PDF compressor allowing is 50 MB. All files together must not exceed 100 MB. 
  • You can select up to 20 files.
  • PDF file quality is scarified when shrinking PDF file greatly.

Alternative Top Online PDF Compressor

1. PDFCompress!

PDFCompress! provides three ways to add PDF files, including My Computer, Dropbox, and Google Drive. This website is very simple, it even doesn’t indicate the maximum file size. But it is super easy-to-use, and the result of PDF Compress is intuitive and reliable.

2. PDF Compressor

PDF Compressor is another online free PDF Compressor for mac which will help users to compress PDF file easily without any downloading and installing. What you need to do is select PDF files from your computer or drag them to the drop area. And then wait until the PDF compression is completed. PDF Compressor allows you to download each file individually, or you can download all of your files at once in a ZIP archive.

Note: You can upload up to 20 files at a time.

3. PDFzipper

PDFzipper gives users a free chance to shrink PDF files with this free online PDF compressor. It will optimize contained images for web viewing, so the file size will reduced even more. It is worth mentioning that registration is not required by PDFzipper. And no advertises or branding will be added to the compressed PDF. You won't be hung out to dry when you use this online PDF compressor.

4. Compress PDF

Compress PDF provides a progress bar for users to view upload progress and compression progress, you can clearly determine the time required. You can add your PDF file only by clicking “Select file”. But its compression may take long time if you upload a large PDF file, so please be patient!

Note: The maximum file size this online PDF compressor allowing is 500 MB.

Things You Need to Know When Using Online PDF Compressor

  • Do not upload highly private PDF files for compression
  • Try different compression mode to decide which one will bring expect compression results
  • Make sure your internet connection is in good condition, so there won’t be no pause or crash when uploading or compressing PDF online


All online free PDF compressors for mac can work with any browser and they are all easy to use. But when talking about compression spread and compression quality, a professional PDF compressor would be more instrumental.

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3 Comments Leave a Reply

  • Walter

    Why is there always a size limit for PDF compression with online service? Mine is often in large size, what a pain.

    2 years ago REPLY
  • Juan


    3 years ago REPLY
  • Steve43

    I wanted to compress my PDF recently, and I tried a free tool. It is really free and useful. Thank you for sharing.

    3 years ago REPLY