Zokilos

PDF Compressor

Upload one or more PDFs, shrink them by recompressing embedded images

🗜️
Click to choose files, or drag them here
.pdf only — multiple files supported
50
Smaller file Higher quality

Lower quality = smaller file, more image artifacts. Text stays sharp either way. Compressing multiple files downloads a single ZIP.

What Is a PDF Compressor?

A PDF Compressor shrinks a PDF's file size — usually by re-encoding the images inside it — so it's easier to email, upload, or store. This one runs entirely in your browser: upload a file, get a smaller PDF back, nothing to install.

How to Compress a PDF Online

1

Upload one or more PDFs (click or drag them in).

2

Set the quality slider and press "Compress PDF."

3

Download the result — a single PDF, or a ZIP if you compressed several.

Reduce PDF File Size Without Losing Quality

The quality slider controls how much the images inside your PDF are compressed. Keep it toward "Higher quality" to shrink the file while keeping images looking sharp; text stays crisp no matter what you choose.

How Does PDF Compression Work?

It re-encodes every embedded image at the quality level you pick, and automatically scales down any oversized image. Repeated content and page data get cleaned up too. Text and vector graphics aren't touched, so a document that's mostly text won't shrink much — the size drop comes from the images.

Why Compress PDF Files?

A smaller PDF is faster to send, quicker to upload, and takes up less storage space — useful any time file size becomes a limit rather than the content itself. A few common cases:

📱

Faster sharing

A smaller file sends faster over a slow connection or mobile data.

🗄️

Archiving

Fit more scanned documents into the same cloud storage or disk space.

🌐

Website uploads

Keep a page fast when it links to or embeds a PDF.

📚

Scanned books & notes

Scanned pages balloon file size fast — compressing keeps a multi-page scan manageable.

Compress Large PDF Files

Scanned documents and PDFs full of photos can balloon into tens of megabytes. Dragging the quality slider toward "Smaller file" gets the biggest size reduction for these.

Compress PDF for Email Attachments

Most inboxes cap attachments around 20-25MB. Compressing a bulky PDF before attaching it is often the fastest way to get under that limit.

Compress PDF for Online Uploads

Job applications, visa forms, and government portals often reject PDFs over a set size — compress first so the upload actually goes through.

How to Make a PDF File Smaller

Upload the PDF, drag the quality slider to balance size against image sharpness, and press "Compress PDF" — the smaller file downloads straight to your device, ready to send or store.

PDF Compression Without Losing Formatting

Compressing only touches the images inside your PDF — text, layout, fonts, and page structure stay exactly as they were. If the result would somehow end up bigger than your original file, you get the original back instead.

Is It Safe to Compress PDF Files Online?

Yes — your file is processed in memory during the request and never written to disk or stored anywhere. No account or sign-up is required to use it.

PDF Compressor for Mobile and Desktop

Works in any modern browser — desktop or mobile, Windows, Mac, iPad, iPhone, or Android. Tap or click to upload, adjust the slider, and compress. No app to install.

Benefits of Using an Online PDF Compressor

  • Shrinks file size without editing the document's text or layout
  • Works entirely in the browser, no software to install
  • Multiple files compress in one pass and download as a ZIP
  • Never returns a file bigger than what you uploaded

Frequently Asked Questions About PDF Compression

How do I compress a PDF file for free?

Upload your PDF above, choose a quality level, and press "Compress PDF" — the smaller file downloads straight to your device, no sign-up needed.

Will this shrink a text-only PDF?

Not much — this tool mainly shrinks the images inside a PDF, so a document with no images won't get much smaller.

What does the quality slider actually change?

How much the images inside your PDF get compressed. Lower means a smaller file but images look a bit rougher; text always stays sharp.

Will large images get resized?

Yes, oversized images are scaled down automatically as part of compressing the file.

Could the output end up bigger than my original file?

No. If compressing wouldn't actually help, you just get your original file back.

Can I compress more than one PDF at once?

Yes. Uploading multiple files compresses each one and downloads them together in a single ZIP.

Need the reverse — turn images into a PDF? Try Image to PDF.