Compress a PDF
Makes a PDF smaller by fitting its images to the size they are shown at on the pages. Text, drawings, bookmarks and links stay as they are. The file is processed only on this device.
- Free
- No upload
- No sign-up
- Works offline
How to use
Press "Choose a PDF" and pick one PDF.
Choose how much smaller: "A little (quality first)", "Standard" or "Much smaller".
Press "Compress and save" to save the smaller PDF (compressed.pdf). If it cannot be made smaller, nothing is saved and the screen says so.
Questions
Is my PDF sent anywhere?
No. Reading the PDF and making it smaller both happen on your device. Nothing is sent out after you choose a file.
How does it make the PDF smaller?
Photos and other images in the PDF are reduced to the resolution that fits the size they are shown at, and saved again as JPEG. Data stored without compression is compressed, and data that nothing uses is left out. Text and drawings made of lines stay as they are.
Is the quality reduced?
A little, for photos and similar images. "A little (quality first)" keeps up to 200 dpi, "Standard" up to 150 dpi, and "Much smaller" up to 100 dpi. Images with few colors, such as charts and logos, are left as they are to keep them sharp, and so is any image that would not get smaller.
Can it fail to make the PDF smaller?
Yes. A PDF with small images, or with text only, may hardly get smaller. When the new file would not be smaller than the original, nothing is saved.
Which images are left as they are?
Images in print colors (CMYK) or special colors, images with few colors, and JPEG 2000, JBIG2 and fax-style images are kept as they are, so that they look the same.
What happens to digital signatures and PDF/A?
If the PDF has a digital signature, that signature is no longer valid, because the file is saved again. A PDF made as PDF/A may no longer meet that standard. Keep the original file of important documents.
What happens to the author and similar details, and to the camera details of images?
They are removed. The author, title, dates and similar details of the PDF (its XMP metadata too), the private data of the programs that made it, the small previews of its pages (thumbnails), and the camera details inside its JPEG images (location, camera, small previews; small JPEGs written inside the pages too) are not kept in the new file. If a JPEG cannot be read, the screen tells you. Removing them does not change how the images look. Bookmarks, form fields, links, comments and attachments stay as they are.
Can I use it on my phone?
Yes. It needs a recent browser (the screen tells you if yours cannot run the tool). Large PDFs may take a while. Inside apps such as LINE, saving may not work. If so, open the page again in Safari or Chrome.
Limits
- PDFs with a password or other protection cannot be used.
- One PDF can have up to 200 MB and 2,000 pages.
- Photos and similar images lose a little quality. Images with few colors or in special colors are left as they are.
- If the PDF cannot be made smaller, nothing is saved.
- Digital signatures stop being valid, and a PDF/A file may no longer meet that standard.
- The author, title, dates and similar details, the small previews of the pages, and the camera details of images (such as the location) are removed. Bookmarks, form fields, links, comments and attachments stay.
- We cannot protect against things in your own environment, such as browser extensions.