PDF vs JPG: which should you use for scanned documents?
You've just scanned a document with your phone, a contract, an ID, a receipt, and the app asks whether to save it as a PDF or a JPG. It's a small decision that's easy to get wrong, because the two formats aren't really competing for the same job.
What each format is actually for
A JPG is a single image. It has no concept of "pages", if you scan a three-page document as JPGs, you end up with three separate image files with no structure tying them together.
A PDF is a document container. It can hold one page or a hundred, and while it's often used to wrap scanned images, it isn't inherently an image format at all, it can also hold real, selectable text, vector graphics, and metadata like a title or author.
When JPG makes sense
Stick with JPG when you're scanning a single page and the destination specifically wants an image, a website upload field that asks for a "photo of your ID," for instance, or when the scan is going straight into another image-editing workflow. JPG is also marginally smaller than a PDF wrapping the same single image, since a PDF carries a small amount of container overhead.
When PDF makes sense
Reach for PDF as soon as more than one page is involved, or when the document needs to look "official", application forms, contracts, and anything you might print later tend to expect a PDF. It also prints far more predictably than an image: a PDF page has a defined size, while an image's print size depends on the resolution it was scanned at and how the printer driver interprets it.
What about PNG instead of JPG?
PNG rarely comes up in this comparison, but it's worth a mention: it's lossless, so a scan saved as PNG keeps every pixel exactly as scanned, with none of JPG's compression artifacts around sharp text or barcode lines. The cost is file size, a PNG scan is typically several times larger than an equivalent JPG. For a receipt with a barcode you might need to scan again later, or a document where crisp text really matters, PNG can be worth the extra size. For the everyday case of "I need to send this document somewhere," JPG's smaller size usually wins.
A mistake worth avoiding: re-saving a JPG repeatedly
JPG compression is lossy, and that loss compounds. If you scan to JPG, open it, make a small edit, and save as JPG again, and repeat that a few times, each save throws away a little more detail, and the artifacts visibly build up around text and edges. A PDF that embeds a JPG once and is then only merged, split, or reorganized (without re-rendering the image) doesn't have this problem, which is one more reason multi-step document workflows tend to land on PDF rather than repeatedly-resaved JPGs.
Converting between the two
Going from images to a PDF or back is quick either way:
- Images to PDF, add one or more JPG/PNG files, reorder them, and get a single PDF.
- PDF to Images, turn each page of a PDF back into its own PNG or JPG at a resolution you choose.
Ready to convert?
Open Images to PDFFrequently asked questions
Does converting a scanned image to PDF make it searchable?
No. Wrapping an image in a PDF just gives it page structure, it doesn't add a text layer. Making a scan searchable requires OCR (optical character recognition), which is a separate, heavier process this site doesn't currently offer.
Which format produces a smaller file?
For a single page, a JPG is usually a bit smaller than a PDF wrapping the same image, because a PDF carries some container overhead. For multiple pages, a single PDF is far more efficient and manageable than several separate JPGs.
Can I combine multiple JPGs into one PDF?
Yes, that's exactly what the Images to PDF tool does: add your JPG or PNG files, put them in order, and it produces a single multi-page PDF.