FreeNo uploadNo sign-upBatch
Compress PDF
Shrink heavy PDFs, especially scans and photo documents, to fit email and upload limits.
Drop PDFs to compress
batch and mixed formats welcome
- Private by design. Converted inside your browser.
- Instant. No upload queue, no waiting.
- Unlimited. Convert hundreds of files, download as ZIP.
How to compress a PDF
Add your PDFs
Drop one or several PDF files on the tool.
Pick a compression level
Recommended suits most files. Strong gives the smallest size; Light keeps more detail.
Download the smaller file
Compare the before and after sizes, then download.
Make a PDF small enough to send
Scanned documents and PDFs made from phone photos are often far heavier than they need to be, which makes them bounce off email attachment limits and upload forms.
This tool rebuilds each page as an optimised image at a lower resolution. That is very effective for scans and photo-heavy files. The trade-off is that text becomes part of the image, so it can no longer be selected or searched. If the result would not be smaller, you get the original back.
Frequently asked questions
How much smaller will my PDF be?
It depends on the file. Scans and photo-heavy PDFs often shrink a lot. Text-only PDFs may not shrink at all; in that case the original is kept.
Why is the text no longer selectable?
Pages are re-saved as compressed images, which is what makes the file small. Keep the original if you need selectable text.
Which compression level should I use?
Recommended (110 dpi) keeps documents readable on screen. Strong (72 dpi) is for the smallest files. Light (150 dpi) keeps more detail for printing.
Are my documents uploaded?
No. Compression runs inside your browser and your PDFs never leave your device.
Are my files uploaded to a server?
No. formatmath converts files with code that runs inside your browser. Your files are never uploaded, stored or seen by us.
Is it free?
Yes. There is no watermark and no daily limit. An account is optional and only keeps a history of your conversions.