PDF vs JPG: Which Format Should You Use?

The short answer: use PDF for documents and JPG for photographs. A PDF keeps pages, text and layout together in one file that looks the same everywhere. A JPG is a single picture, compressed in a way that suits photos but blurs sharp text. The rest of this guide covers the cases in between, such as scans, forms and upload portals that only accept one format.

What Each Format Actually Is

PDF (Portable Document Format) is a container for pages. Each page can hold real text with embedded fonts, vector drawings that stay sharp at any zoom, and images. It supports many pages, links, fillable forms, passwords and printing at an exact size.

JPG (or JPEG) is a single raster image: a grid of pixels. It uses lossy compression designed for photographs, which throws away detail the eye is unlikely to notice in natural scenes. It can't hold multiple pages, and any text in it is just pixels.

PDF vs JPG at a Glance

• Pages: a PDF can hold hundreds of pages in one file; a JPG is always one image.
• Text: PDF text can be selected, searched and read aloud by screen readers; JPG text is part of the picture.
• Zooming: PDF text and vector graphics stay sharp at any zoom; a JPG gets blocky once you zoom past its resolution.
• Sharp edges: JPG compression creates faint smudges around high-contrast edges like black text on white, which PDF text avoids.
• File size: for a single photo, JPG is usually smaller. For a text document, PDF is much smaller. For scans, they're about the same, because a scanned PDF is essentially JPG images inside a PDF.
• Printing: PDFs print at the intended paper size; a JPG's print size depends on the app and settings.
• Protection: PDFs support passwords and permission settings; JPGs have none.

When to Choose PDF

• Anything with more than one page, such as contracts, statements, reports or a multi-page scan.
• Job applications, CVs and cover letters, where recruiters and screening software need selectable text.
• Invoices, receipts and official forms you'll email or upload.
• Documents that will be printed, especially at a specific paper size.
• Anything with small print, tables or diagrams that people need to read closely.

When to Choose JPG

• Photographs you'll share on screen, post on social media or embed in a website.
• Upload forms that only accept image files, such as some profile-photo or ID-photo fields.
• A quick preview of a single page when the recipient only needs a glance.

What About Scanned Documents?

A scanned page is a photo of paper, so inside a scanned PDF each page is usually stored as a JPG-style image. The file size is similar either way. The advantage of PDF is organisation: all pages in one file, in the right order, that opens at the right paper size. Sending one 5-page PDF is far easier for the recipient than five separate images.

Common Mistakes

• Emailing a dozen phone photos of a document instead of one PDF. The recipient has to open, rotate and order them by hand.
• Converting a text PDF to JPG to make it smaller. The text becomes blurry and unsearchable, and the file often gets bigger.
• Re-saving the same JPG repeatedly. Each save discards more detail, so quality drops a little every time.
• Saving documents with small print as low-quality JPGs, which makes numbers and fine print hard to read.

Turning Photos or Scans Into One PDF

Your phone can already do this. On iPhone, the Notes and Files apps have a Scan Documents option that saves straight to PDF. On Android, the Google Drive app has a Scan button that does the same. On a computer, open the image and print it with Microsoft Print to PDF on Windows, or choose Save as PDF in the print dialog on a Mac.

If you end up with several single-page PDFs, merge them into one file and put the pages in order. Rotate any sideways pages, then compress the result if it's too large to send.