Compress PDF
Shrink a PDF so it fits a form's upload limit, with the file never leaving your device.
Compress PDF
In short: Compress PDF
Compress PDF makes a PDF smaller inside this page, which matters because the forms that demand a small file are usually the ones asking for identity documents. Daytoolz re-encodes the pictures inside the file on your device, so the document itself is never handed to anyone.
What is Compress PDF?
Compressing a PDF means re-encoding the images inside it at a lower quality, which is where almost all of the size in a scanned document sits.
How is Compress PDF calculated?
Almost all of the size in a scanned PDF is in its images, so compression re-encodes those at a lower quality and leaves the text alone. The saving is the drop in size as a share of the original.
- size_beforethe size of the file you chose
- size_afterthe size of the file written back
How to use this compress PDF
- Choose the PDF, or drag it onto the box.
- Pick how hard to compress. Light keeps the most quality.
- Start it, and watch the size before and after.
- Save the smaller file if the quality still suits the purpose.
Questions people ask
Why did my file barely get smaller?
Because a PDF made from text rather than scans has very little to compress; the size is in fonts and structure, not pictures. Scanned documents shrink a great deal, text documents hardly at all. Check whether your pages are images or real text.
Will the text still be selectable?
Yes, text is left exactly as it is; only the images are re-encoded. A scanned page is a picture throughout, so compressing it softens the whole page. That is the trade-off the strength setting controls.
How do I hit an exact size limit?
Start with the balanced setting and step up to strong if the file is still too large. If a scanned document still will not fit, photographing the pages again at a lower resolution usually beats compressing an already-compressed file.
What if the file cannot get any smaller?
You are told so, and no file is offered. A picture is only replaced when the new version is clearly smaller, and anything that cannot be redrawn faithfully, such as masks or print colours, is left untouched. Text and fonts are never changed.
Accuracy and sources
Checked by the Daytoolz team on 16 October 2026. How we check our tools.