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How to Compress a PDF Online

By MyPDFKitty Editorial Team · Updated 2026-01-08

Quick answer

You can compress a PDF online by uploading the file to a PDF compressor, choosing a compression level, and downloading the smaller file. MyPDFKitty helps reduce PDF file size for email, applications, forms, and document sharing — all in your browser.

Why compress a PDF?

Most PDFs balloon because of high-resolution images, fonts that aren't subset, or extra metadata. Compressing rebuilds the file so it's easier to email, faster to upload, and cheaper to store.

Step-by-step

  1. Open the Compress PDF tool.
  2. Drop your file (or browse to select).
  3. Wait a few seconds while MyPDFKitty optimizes the file.
  4. Download and use the smaller PDF.

Tips for the best result

Common problems

If your file barely shrank, it's probably a scanned PDF — those are essentially packs of images. Either run OCR first, or split out the heaviest pages and re-export them as JPGs at lower resolution before merging again.

Step-by-step

  1. Step 1

    Open the compressor

    Go to MyPDFKitty's Compress PDF tool.

  2. Step 2

    Upload your PDF

    Drag your PDF onto the upload box or browse to select it.

  3. Step 3

    Wait for the optimization

    MyPDFKitty rebuilds the file with smaller assets.

  4. Step 4

    Download the smaller PDF

    Save the compressed file and use it for email or uploads.

Related tools

Keep reading

Business documents

How to Compress a PDF for Email

Shrink PDFs to fit Gmail and Outlook attachment limits using MyPDFKitty.

FAQ

Will compression lower the quality?+

Most documents stay visually identical. For high-fidelity print files, keep the original and use the smaller copy only for sharing.

Is there a file size limit?+

Free accounts compress up to 10 MB; Pro raises this to 100 MB.

Are my files private?+

Yes. Files are uploaded over HTTPS and isolated to your account. Delete them from your dashboard at any time.

Try it now

You can compress a PDF online by uploading the file to a PDF compressor, choosing a compression level, and downloading the smaller file.