How to use the Compress PDF tool
- Add your PDFDrop the PDF onto the box or click to choose it. You will see its size and page count.
- Pick a levelRecommended suits most files. Extreme gives the smallest size, Light keeps images closest to the original.
- CompressClick “Compress PDF”. Each image is resized and re-encoded in your browser.
- DownloadThe smaller PDF downloads automatically, and you can see exactly how much space was saved.
Features
- Big savings on scans and photosScanned documents and photo-heavy PDFs often shrink by 50–90%, because images are where most of the size is.
- Text and vectors untouchedText, fonts, links, form fields and drawings are kept exactly as they are, so text stays crisp and searchable.
- Never makes a file biggerIf an image wouldn’t get noticeably smaller it is left as it was, and you are told when a file is already optimized.
- Optional metadata cleanupRemove XMP metadata and embedded page thumbnails for a little extra saving and privacy.
- Private by designYour PDF never leaves your device. All compression runs in your browser.
Why are some PDFs so large?
A PDF’s size depends almost entirely on what is inside it. A 20-page text document created in Word is usually under 500 KB. The same 20 pages scanned on a phone or an office scanner can easily be 20–50 MB, because every page is stored as a high-resolution photo. Brochures, catalogs and reports full of pictures are large for the same reason.
That is why this tool focuses on images. It finds each photo or scan in the PDF, scales it down to a sensible resolution and saves it again as an efficient JPEG. Everything else in the file is kept.
Which compression level should I choose?
| Level | Longest image side | Best for |
|---|---|---|
| Extreme | 1000 px | Strict upload limits (for example 100 KB–1 MB on government and job portals) and sharing over chat apps. |
| Recommended | 1600 px | Email attachments and everyday sharing. Scans stay easy to read on screen and when printed. |
| Light | 2400 px | Documents you may print at full page size or where photo detail matters. |
If the result is still too big, run the compressed file again with Extreme, or use Split PDF to send it in parts. Removing unneeded pages with Delete PDF Pages also helps.
Why didn’t my PDF get smaller?
- It is mostly text. Text PDFs are already compact, and their size comes from fonts and page content, which this tool does not change.
- Its images are already compressed. Many apps already save scans at a low resolution, so there is little left to gain.
- It uses special image types. Black-and-white fax-style scans (JBIG2, CCITT), CMYK print images and some other formats are left unchanged to avoid colour or quality problems.
Is the quality still good?
For reading on screen, yes. A page image 1600 pixels tall is sharper than most laptop screens can show, and text in scans stays clear. Compression is lossy, though, so keep your original if you might need the full-resolution scans later. Typed text, vector drawings and fonts are never re-encoded, so they look exactly the same.
Is my PDF uploaded anywhere?
No. Unlike most online compressors, this tool runs entirely in your web browser. The file is read and rewritten on your device and is never sent to a server, which makes it safe for bank statements, ID documents and contracts. Password-protected PDFs need to be opened with Unlock PDF first.