I Hack PDF
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Compress PDF

Reduce file size with lossless optimization or image compression.

Read the guide ↓

What this tool does

Reduce PDF size with a mode that matches the document. Try lossless optimization for ordinary files, or choose an image-based mode when a smaller visual copy matters more than interactive features.

What you can open
One PDF and a compression mode; image modes also use a rendering resolution.
What you will download
An optimized PDF, or the original-sized result when further reduction is not possible.

How to use it

  1. Start with lossless mode when text, links or forms must remain usable.
  2. If a smaller visual copy is suitable, choose balanced or smallest and set a resolution.
  3. Compare the result with the original for both size and readability.

Options explained

Compression
Lossless mode preserves page content. Balanced and smallest modes rebuild pages as images and remove interactive document features.lossless / balanced / smallest
Image mode resolution, DPI
Set the rendering resolution. Higher values can improve visible detail but use more memory and create larger files.

Know the tradeoffs

  • Some PDFs are already efficient and cannot be made smaller.
  • Image modes rebuild pages and remove selectable text, forms, links and digital signatures.

Questions about this tool

Does compression always reduce file size?

No. Already optimized or very small files may not benefit.

Which mode should I use for a fillable form?

Start with lossless mode. Image-based modes remove interactive form fields.