What actually makes a PDF large
Text in a PDF costs almost nothing. A fifty-page contract is usually well under a megabyte. When a file is large, the weight is nearly always in images: scanned pages stored as full-resolution photographs, or pictures placed into a document at the size they came off a camera rather than the size the page displays them at.
That is what this tool targets. Each page is rendered at a sensible resolution and re-encoded as a compressed image, which is why a 40 MB scan can drop to a small fraction of its size.
The trade-off, stated plainly: because every page becomes an image, the text stops being selectable and searchable. For a scan that was already images, you lose nothing. For a text document, you lose something real — and gain very little, since text was never the problem.
When to use this, and when not to
- Good fit: scanned documents, photo-heavy reports, presentations exported to PDF, anything that will not fit an email attachment limit.
- Poor fit: contracts and reports that are mostly text, anything you need to search, and any document that will be read by a screen reader.
- Better alternative: if you only need part of the document, removing pages with the split tool preserves everything and often shrinks the file more than compression would.
Choosing a setting
Balanced suits most scans and keeps ordinary print legible. Strong is for when the file must fit a hard limit and the document is a reference copy rather than something to be read closely. Light barely changes appearance and is worth trying first on anything containing small print.
The width limit usually matters more than the quality setting. A page scanned at 300 dpi is around 2500 pixels wide; capping it at 1600 removes a great deal of data while remaining perfectly readable on screen.
Check the result before sending
Compression is not free, and small print is where it shows first. Open the compressed file and look at the smallest text, any signatures, and any stamps or seals. For anything legal, financial or medical, this check takes seconds and occasionally saves an entire round trip.
Frequently asked questions
Is my PDF uploaded anywhere?
No. The file is opened, re-rendered and rewritten inside your browser. Nothing is transmitted and no copy is kept.
Why did my text-only PDF barely shrink?
Text takes almost no space in a PDF. If a file is large the weight is in images, so a document that is mostly text has little to compress and may even grow slightly.
Does compressing make the text unselectable?
Yes. Each page is re-encoded as an image, so text can no longer be selected or searched. For scanned documents this changes nothing, since they were already images.
How much smaller will my file get?
It depends entirely on what is inside. Scans and photo-heavy documents often drop by a large margin; text documents barely move.
Will small print still be readable?
At the Balanced and Light settings, usually yes. Always open the result and check signatures and small print before sending anything important.