Table of contents
Most format mistakes are habit, not confusionThe three in one passHow to actually decideA short checklist before you send anythingMost format mistakes are habit, not confusion
People do not usually pick the wrong format because they misunderstand it — they pick it because it is the one they always use, regardless of what the destination actually wants. Checking what a website, printer, or recipient accepts before converting solves most of these problems immediately.
Combine images or export a page
Whichever direction you need, the tools below handle both JPG/PNG and PDF conversion.
The three in one pass
JPG: best for photo-like images at a manageable file size. Widely supported, generally the safe default for scans, page previews, and website photos.
PNG: best for screenshots, flat graphics, and anything needing transparency or sharp text edges. Larger files, but it avoids the compression artifacts JPG introduces.
PDF: best for anything with more than one page, or where layout, print consistency, and structure matter — applications, invoices, reports, contracts.
How to actually decide
Is it one image or multiple pages? Multiple pages almost always means PDF.
Does the recipient require a specific format? If so, that answer overrides your own preference.
Does the text need to stay selectable? Only PDF preserves that; both image formats flatten text into pixels.
Convert only when the destination requires it — a PDF should not become loose images unless someone specifically wants image files, and scattered images should become one PDF when someone wants a single document.
A short checklist before you send anything
MDN's guide to common image file types is a good reference if you want more technical depth on JPG and PNG specifically.
When genuinely unsure, keep the original file and create a copy in whatever format is requested — that preserves flexibility without sacrificing your best source file.
Match the format to the next step
Convert based on what happens after you send the file, not habit.
FAQ
Is JPG always smaller than PNG?
Often, for photos — but size depends on dimensions and image content, not the format alone.
Can I combine JPG and PNG into one PDF?
Yes — a JPG to PDF tool that also accepts PNG can combine both into one document.
Which format should I use for uploads?
Whatever the upload form specifically requests; if several are accepted, choose based on document versus image needs.
Which format keeps transparency?
PNG. JPG does not support transparency.
Which is best for printing documents?
PDF, for predictable page size and layout.