Reduce PDF File Size

Yes, as long as there is text in the file. Those are packed down without anything being drawn again, so the text is left alone. Only scans get turned into pictures, and a scan had no text to lose in the first place.

How coarsely a scan gets drawn. On a PDF that has text it changes nothing at all, because nothing is drawn again.

In a PDF with text they survive, because the file is never rebuilt. A scan is rebuilt out of pictures, so anything clickable in it goes — though a scan rarely has any to begin with.

If there is text on any page, the whole file gets packed down rather than drawn again. The scanned pages come through untouched, so you save less than you would on a file that is nothing but scans.

Yes. You reduce PDF file size in your browser, so all of it happens on your own machine and the document is never uploaded.

Size limits exist to control bandwidth and server time. Neither applies when the work happens on your own machine.

It depends on the file. A 600 dpi scan can drop by 80 percent or more. A PDF with text gives back much less, sometimes only a few percent, because nothing is being thrown away. Either way, if there is nothing to save you get the original back.

On a PDF with text, yes. The hidden structure that screen readers use to follow headings, tables and reading order is removed, because it is often a large share of the file. What you see does not change: the layout, the text, and your ability to select and search it all stay the same. If the PDF has to stay accessible for screen reader users, send the original instead.

In a PDF with text, yes. Form fields are kept whenever the file has any. Only an empty form shell that some programs leave behind is removed. A scan is different: it is rebuilt from pictures of its pages, so anything clickable or fillable in it does not survive, though scans rarely have form fields to begin with.

Yes. Add them all and press Start. Each file shows how much it shrank, and the page shows the total before and after. Files that got smaller come back with -small added to the name. Files that could not be made smaller are handed back unchanged. With more than one file, everything comes in a single zip called compressed-pdf.zip.