Compress PDF
Make a PDF smaller so it fits in an email or an upload form. Choose how far to go; text always stays sharp. It all happens in your browser, so the document never leaves your device.
Where the size of a PDF comes from
In most large PDFs it is the pictures: scanned pages and photos, often saved at a quality and size far above what a screen or a printer needs. Text and drawings are small by comparison, but a file can also carry things it no longer uses, such as earlier versions of edited pages that an ordinary save keeps.
What each level does
Lossless changes nothing you can see. The file is written again from its contents, so what it no longer uses is left behind, and its text, drawings and the table of where everything is are packed tighter. Balanced also saves colour photos again as JPEG at good quality, and makes any that are longer than 2400 pixels smaller, which is still sharp on a full page. Strong goes to quality 0.6 and 1600 pixels, and turns other colour pictures, such as screenshots, into JPEG too.
Text is never turned into a picture, so it stays sharp and searchable at every level. A picture is only replaced when the new one is smaller, and when the whole result is not smaller than the original, the page says so and saves nothing.
Left as they are
Grey pictures, which are often scans of text or the soft edges of shadows, pictures in printing colours (CMYK) and pictures that serve as another picture's mask keep every byte: saving them again could change how they look or print. A digitally signed PDF loses its signature when it is compressed, because the signature covers the file's exact bytes; the page tells you before you save.
Frequently asked questions
Will the text become blurry?
No. Text is kept as text at every level, never turned into a picture. Only photos and other pictures are saved again, and only at Balanced and Strong.
Which level should I choose?
Balanced, for most files: photos keep good quality and the file usually gets much smaller. Use Lossless when nothing may change at all, and Strong when the file has to fit a tight limit.
Why did my PDF not get smaller?
It was already packed tightly, or most of it is text, grey scans or pictures this page leaves alone. The page never hands you a bigger file: it tells you instead.
Is the result still a normal PDF?
Yes. It uses the packed layout of PDF 1.5, which every PDF reader of the last twenty years opens, and keeps the pages, bookmarks, links and forms.
Can it compress a password-protected PDF?
No, its contents are encrypted. Open it in your PDF reader with the password, save a copy without protection, compress that, and protect the result again if you need to.
Is my PDF uploaded?
No. The PDF is read, made smaller and written again by JavaScript inside your own browser, and the result is saved straight to your device. Nothing is uploaded and nothing is stored - close the tab and it is gone.