PDF Compressor

Shrink a PDF file. “Optimize” rewrites the file structure without touching the pages; “Flatten” converts pages to compressed images for maximum savings.

Your PDF is processed entirely in your browser and is never uploaded to a server.

How to use PDF Compressor

  1. Upload the PDF you want to compress.
  2. Choose “Optimize” for lossless structural compression, or “Flatten” to compress pages as images.
  3. For Flatten mode, pick an image quality — lower quality means a smaller file.
  4. Press “Compress PDF” and download the smaller file.

About this tool

PDFs grow large for different reasons: some carry unused objects and metadata, others embed huge images. Optimize mode rewrites and re-compresses the document structure, which helps many files without changing a single pixel.

When a PDF is mostly large scanned pages or embedded images, Flatten mode re-compresses every page as an image. It can reduce size dramatically, but it rasterizes the pages — text will no longer be selectable or searchable.

When to use it: when a PDF is too large for an email, an upload portal or a government application form.

Frequently asked questions

What is the difference between Optimize and Flatten?
Optimize keeps pages fully intact (text stays selectable) and trims structural overhead. Flatten re-renders each page as a compressed image for much stronger compression, at the cost of losing selectable text.
Why is PDF compression done in the browser?
It keeps your documents private and makes the tool free to run. The trade-off is that the browser cannot match the very aggressive compression of desktop tools like Adobe Acrobat.
Will compression reduce the quality of my PDF?
Optimize mode does not reduce quality at all. Flatten mode reduces quality according to the setting you choose, similar to saving an image as a lower-quality JPG.
My PDF barely shrank. Why?
PDFs that are already well-compressed, or that are mostly text, have little to remove. Flatten mode with a lower quality setting will usually make them smaller.
Which mode should I choose?
Try “Optimize” first — it is lossless. If the file still needs to be smaller, “Flatten” rasterizes the pages and saves much more, at the cost of selectable text.
Will Flatten make the text unselectable?
Yes, pages become images, which is exactly why it compresses so much better. Keep an original copy if you need the text layer later.

Related tools

PDF to Images Convert each page of a PDF into a JPG or PNG image. Images to PDF Turn JPG, PNG or WebP images into a single PDF document. PDF Merger Combine multiple PDF files into a single document, in the order you choose. PDF Splitter Split a PDF into separate files — every page, or custom page ranges.

Browse all PDF Tools →

How to use Pdf Compressor

Upload your image to the Pdf Compressor canvas by dragging or clicking. Configure settings such as quality, dimensions, or filter options as needed, then start processing. The output renders in the same tab and can be saved directly.

Practical benefits

Frequently asked questions

Is this tool free to use?
Yes. Pdf Compressor is fully free with no account or subscription required.
Does it upload my files?
No. All processing occurs locally within your browser session.
Can I use this for professional projects?
Yes, the tool is designed for both casual and professional use. Always verify critical outputs.