How this PDF compressor works
A PDF is mostly made of three things: text, which is tiny; vector drawings, which are small; and images, which are almost always what makes a file large. A scanned page or a phone photo can easily weigh more than a whole book of text.
So this tool leaves the text and drawings alone and works only on the images. Each photo or scan is decoded, scaled down to a sensible resolution and re-encoded as an efficient JPEG; if the new version is not clearly smaller, the original is kept. Unlike tools that turn every page into a picture, your text stays selectable and searchable and prints just as crisply.
Which setting to choose
| Setting | Images become | Good for |
|---|---|---|
| Light | Up to 2600 px, high quality | Printing, photo-heavy brochures you still want to look good |
| Recommended | Up to 1800 px, good quality | Email attachments and upload forms - the best balance |
| Strong | Up to 1200 px, lower quality | Strict size limits, such as 2 MB on government and job portals |
When a PDF will not get smaller
If a PDF contains no photos - a contract exported from Word, say - there is little left to compress, and the tool tells you so rather than handing back a file that is only a few bytes lighter. The same happens when the images are already efficiently compressed. Very large text-only PDFs usually owe their size to embedded fonts, which have to stay for the document to look right.
Need to combine files first? Use Merge PDF, then compress the result.
How your files stay private
Most free converters upload your file, process it on their server and send the result back - so a copy of it passes through somebody else's machine. This page does all of the work in your browser instead. The files you choose are read into memory on your own device, processed there and handed back as a download; none of their contents is transmitted. You can switch off Wi-Fi after the page has loaded and it keeps working.