Images to PDF

Page size is the decision that matters

An image has pixel dimensions; a PDF page has physical dimensions. Converting requires deciding how one maps to the other. Fitting each image to a fixed A4 or Letter page produces a document that prints predictably and is what you want for receipts, forms and anything destined for a printer. Sizing each page to the image instead produces a document with varying page sizes that displays perfectly and prints awkwardly. Choose based on whether the result will be printed or only viewed.

Resolution and print quality

An image placed on a page at 72 pixels per inch will look fine on screen and visibly soft in print. For printed output you want around 300 pixels per inch across the printed area, which means roughly 2480 by 3508 pixels to fill an A4 page. A phone photograph typically exceeds this comfortably; a screenshot typically does not, which is why screenshots converted to PDF look sharp on a monitor and blurry on paper.

Conversion does not add a text layer

A PDF made from photographs or screenshots contains images, not text. It cannot be searched, the text cannot be selected, and a screen reader finds nothing to read. If you need any of that, the document has to go through OCR after conversion. This is the most common misunderstanding about image-to-PDF conversion: the file looks like a document but behaves like a picture.

File size

JPEG images are already compressed and embed almost as-is. PNG images of photographs are usually far larger than the equivalent JPEG and will inflate the PDF considerably, so converting photographic PNGs to JPEG first can cut the result dramatically with no visible difference. PNG remains the right choice for screenshots with sharp text.

Local conversion

Images are read and the PDF assembled in your browser. Photographs of documents, identity papers and receipts never leave your device.