title: "When to use JPG vs PDF for scanned documents (and how to convert between them)" slug: "jpg-vs-pdf-guide" date: "2026-04-20" excerpt: "JPG and PDF serve very different purposes. Learn when each format is appropriate and how to convert between them without losing quality." readingTime: "6 min read"
The choice between JPG and PDF comes up constantly when dealing with scanned documents, photos of receipts, and paperwork you need to submit digitally. Most people default to whichever format their phone or scanner produces — which is often the wrong choice for what they actually need to do.
This guide explains what each format is for, which one to use in common scenarios, and how to convert between them.
JPG and PDF solve different problems
JPG (technically JPEG — Joint Photographic Experts Group) is a raster image format. It stores a grid of pixels. Every pixel has a colour value, and the JPEG algorithm compresses the data by discarding colour information the human eye is unlikely to notice in natural images. A JPG file is simply an image: it has width and height, a resolution in pixels, and colour data. Nothing more.
PDF (Portable Document Format) is a document container. It can hold multiple pages, text that can be searched and selected, vector graphics (which scale infinitely without pixelation), fonts, form fields, digital signatures, and embedded images. A PDF of a scanned document is usually a PDF containing one JPG or PNG image per page — but it can also contain actual text if the document went through OCR (optical character recognition).
Choosing the wrong format creates real problems. Submitting a JPG to a portal that expects a PDF causes an upload error. Saving a scan as a PDF when the recipient needs an editable image makes it harder for them to work with. Understanding which to use when saves time.
When to use JPG
Use JPG when:
- You are sharing a single photo or image. Social media, messaging apps, and email handle JPGs well. Viewers can see the image without opening a document application.
- The recipient needs to open the file in a standard image viewer. All operating systems include an image viewer; not all include a PDF reader (though most modern browsers handle PDFs natively).
- The file will be displayed on a website or used in a design. JPG is the universal format for web photography.
- You are sending a product photo, profile picture, or artwork. Image editing applications (Photoshop, GIMP, Preview) work natively with JPG.
- You need the smallest possible file size for a photograph. At equivalent quality, JPG is typically smaller than PDF-wrapped JPG because the PDF container adds overhead.
Use JPG instead of PNG for photographs — PNG is lossless and produces larger files for photographic content. Use PNG for screenshots, logos, and graphics with flat colours or text.
When to use PDF
Use PDF when:
- The document has multiple pages. PDFs handle multi-page documents natively; JPG does not. A 5-page scanned contract should be one PDF, not five separate JPGs.
- The exact layout must be preserved for printing. PDF embeds font and layout information so the document looks identical on every printer and screen.
- You are submitting a form. Most official submission systems (tax authorities, universities, legal portals) accept PDF, not image files.
- You need the document to be unsearchable in a specific way. PDFs can contain searchable text (via OCR) or be image-only (scanned without OCR). The format supports both.
- You are combining multiple documents into one submission. PDFs can be merged; JPGs cannot be combined into a single multi-page file without conversion.
How to convert JPG to PDF with OffCloud.tools
OffCloud.tools Image to PDF converter converts one or more JPG, PNG, or WebP images into a single PDF, entirely in your browser.
- Navigate to OffCloud.tools Image to PDF.
- Drop one or more image files onto the drop zone.
- Drag the thumbnails to arrange the page order.
- Choose a page size (A4, Letter, Legal, or Auto), orientation, and margin.
- Set the image fit: Fit (image fully visible within page margins), Fill (image covers full page), or Actual size.
- Click Create PDF. The PDF downloads immediately.
The PDF is assembled in your browser using pdf-lib. No image is transmitted to a server.
How to extract a JPG from a PDF
If you need to extract an image from a PDF (for example, a signature page, a chart, or a photograph embedded in a report):
- Screenshot method: Open the PDF in any viewer, navigate to the page, and take a screenshot. On macOS, Cmd+Shift+4 captures a selection. On Windows, Snipping Tool captures any area. This works but produces a lower resolution result.
- Browser print method: Open the PDF in Chrome or Firefox, use Print → Save as PDF with a custom page range to extract specific pages as a new PDF.
OffCloud.tools does not currently support PDF-to-image extraction — this is a known limitation. For one-off needs, the screenshot method above is the most practical approach.
Common mistakes and how to avoid them
Scanning directly to JPG when you need a PDF. If your scanner saves to JPG, you will need to convert before submitting. This is a common source of "file type not accepted" errors on official portals.
Applying JPG compression to a PDF. PDF files and image files require different compression approaches. Running a PDF through an image compressor treats the PDF bytes as an image and produces a corrupted or degraded file. Use a PDF-specific compressor (or, for scanned PDFs, reduce the resolution of the embedded images before creating the PDF).
Scanning at very high DPI when you do not need it. A 600 DPI scan of an A4 page is 4961 × 7016 pixels — roughly 35 megapixels. For a document you will submit as a PDF and the recipient will read on screen, 150–200 DPI is perfectly adequate and produces a file roughly 16× smaller.
External resources
- Adobe's PDF file format overview — The ISO 32000-1 PDF specification.
- W3C — JPEG 2000, JPEG, and other image formats — W3C documentation on JPEG as a web standard.
- NIST SP 1800-21B — Mobile Device Security — NIST guidance that covers image and document handling in secure contexts.