Only embedded images are resampled and re-encoded, and only when the result is at least 8% smaller; text is never rasterized, so the file stays sharp and searchable. Compression holds the whole document in memory, which is tighter on a phone than on a laptop: a guard at intake says what the device can hold, heavy jobs run in the background and can be cancelled without counting against the day, and very large scans are better compressed on a computer. Nothing is uploaded; add Bindery to the home screen from Safari’s share sheet and it works offline.
How it works
- Open Bindery in Safari and choose the PDF from Files
- Read the three computed sizes on the cards
- Download the level that fits and attach it from Files
Questions people ask
How big a PDF can an iPhone compress?
It depends on the phone’s free memory rather than on Bindery. The intake guard tells you before a job starts whether this device can hold the file; typical scans and decks of a few tens of megabytes are fine, while very large files are quicker on a laptop.
Will the recipient see a difference?
At Balanced, not at normal zoom: images stay at 150 DPI and text is untouched. Email & web at 96 DPI is for screen reading and looks softer when printed. The size of each level is on its card, so you choose by comparing numbers rather than guessing.
Does compression work offline on the phone?
Yes, once Bindery has loaded. Add it to the home screen and it opens as an app without a connection; the compressor and every other tool run on the device, which is also a simple way to confirm nothing is being uploaded.