About PDF Compressor
Scanned documents and PDFs full of photos are often too large to email or upload. This compressor renders every page and rebuilds the PDF from compressed images at a resolution and quality you pick, keeping the original page sizes. For scans and photo-heavy files the savings can be large. There is an honest trade-off: because pages become images, text in the result can no longer be selected, searched or copied, and a PDF that is mostly plain text may even get bigger. The tool shows the new size so you can decide which file to keep.
How to Use It
- 01
Add a PDF
Drop one or more PDF files into the box, or tap to pick them.
- 02
Pick resolution and quality
100 DPI at 60% suits on-screen reading. Use 150 DPI if the PDF will be printed.
- 03
Compare and download
Press Compress, check the new size, and download the smaller PDF.
Why PDF files get so big
Most large PDFs are large because of images. A document scanned at 300 or 600 DPI stores every page as a full-resolution picture, and a PDF exported from a design app may embed photos at print quality. Text, by contrast, takes almost no space: a 100-page novel as plain text can be under 1 MB.
That's why scanned documents, brochures and photo-heavy reports shrink dramatically when compressed, while a text-only PDF straight from Word may barely change, or can even grow.
Fonts can add weight too. A PDF that embeds several complete font families may carry a few megabytes of font data, which compression removes along with everything else when the page becomes an image.
Picking resolution and quality
100 DPI is plenty for reading on a screen and gives the smallest files. Choose 150 DPI if the document may be printed, so small text stays crisp on paper. Lower JPEG quality squeezes the images further; around 70% is a good balance for scans, and you can go lower for documents that only need to be legible.
The tool shows the size before and after for every file, so you can try a setting, check the result and adjust if it's not small enough.
Meeting email and upload limits
Gmail and Outlook cap attachments at about 20–25 MB, and many job portals, university and government forms accept only 1–5 MB. For a 2 MB limit, start at 100 DPI and 70% quality. If one long document is still too big, you can split the PDF into parts and send them separately, or compress each part.
Tips for the smallest file
Start with the defaults and only go lower if you must: a page that is too blurry to read is worse than one that is slightly large. Colour scans of black-and-white letters waste space, so if you scan documents yourself, choose greyscale or black-and-white in your scanner app. Removing pages nobody needs, such as blank backs of double-sided scans, also helps; pull out the pages you want with Split PDF using Extract before compressing.
Several PDFs at once? Add them all; each is compressed with the same settings and you can download them together as a ZIP.
What to know before you compress
Compression saves each page as an image, so text in the result can't be selected, searched or copied, and form fields and links are flattened. Keep the original file if you'll need to edit it, fill in fields or copy text later. If you need the text from a scanned PDF, extract it first with OCR, then compress the copy you send.
Questions
Which PDFs does this work best on?
Scanned pages, photographed documents and PDFs with large images. These often shrink a lot. Text-only PDFs are already small and usually won't benefit.
Why can't I select text in the compressed PDF?
Each page is saved as an image so it can be compressed. Keep the original if you need selectable or searchable text.
Will the PDF still print well?
At 150 DPI text is readable when printed, though not as crisp as the original. For on-screen use, 100 DPI is usually enough.
Are password-protected PDFs supported?
No. If a PDF needs a password to open, remove the password in a PDF app you trust first.
Is my document uploaded?
No. Pages are rendered and compressed in your browser, and the new PDF is built on your device.