Compress PDF Online Free

How to compress a PDF

1. Drop your PDF onto the box above, or click it to browse.
2. Pick a compression level, or switch to target size and type the exact size you need.
3. Press Compress. Everything runs on your own machine, so the time it takes depends on your computer, not on an upload.
4. Download the result under its original filename.

What the three levels actually do

Less compression re-encodes the images inside the file at a gentler quality setting and leaves everything else untouched. Text stays text, so it is still selectable and searchable, and the layout is byte-for-byte the same.

Recommended downsamples images more aggressively. This is the setting that gives most people a big drop in size with no visible difference on screen, because most PDFs are heavy for one reason: photographs saved at far higher resolution than a screen or a printer will ever use.

Extreme takes a different route. It renders each page to an image and rebuilds the PDF from those. That guarantees a smaller file even when the original has nothing left to squeeze, but the text becomes part of the picture, so you can no longer select it, search it, or copy it. Use it when a hard size limit matters more than the text layer.

Target size mode

If a portal demands "under 2 MB", switch to target mode and say so. The tool compresses repeatedly, tightening quality each pass, until the file lands at or under your number. Choose KB or MB, because the units portals use are rarely the ones you would pick yourself.

Frequently asked questions

Are my documents uploaded anywhere?

No. The PDF is opened in your browser's memory and processed there. Nothing is sent to a server, which is also why the tool keeps working if your connection drops mid-way.

Why did my file barely shrink?

Because it was probably already efficient. A PDF that is pure text and vector graphics, an invoice exported from accounting software for example, has almost no wasted bytes. Compression works on images, and a file with no images has nothing to give. The tool will tell you when it finds no images to shrink.

Will the quality visibly drop?

At the first two levels, rarely. Screens show roughly 100 to 150 pixels per inch, and phone cameras produce far more detail than that. Extreme is the level where you should check the output before sending it on.

Does it work on scanned documents?

Yes, and scans are where it helps most, because a scan is nothing but images, so there is a lot to reclaim.