PDF vs JPG for document uploads
Updated 2026-09-20
A passport scan, a degree certificate, a bank statement, a signed form: most portals accept either a PDF or a JPG, and a few insist on one. PDF is a document container: it can hold many pages, embedded text you can search and select, vector graphics and, importantly, a scan of any number of pages as a single file. JPG is a single raster image: one page, no text layer, but universally previewable and easy to compress to a size limit.
The rule of thumb used by most portals is "photos as JPG, documents as PDF". Where the form gives you a choice, the number of pages and the size limit decide.
Side by side
| Criterion | JPG | |
|---|---|---|
| Pages per file | Unlimited | One |
| Searchable, selectable text | Yes, if created digitally or OCR-processed | No |
| Typical size of one scanned A4 page | 100 KB to 1 MB depending on the scan settings | 150 KB to 1 MB; easy to push under a limit |
| Compressing to a KB limit | Harder; needs a PDF tool or re-scanning at lower resolution | Easy; image compressors target an exact size |
| Preview in the browser and on phones | Yes in every modern browser; some portals show only an icon | Always shows as a picture |
| Can be edited or altered easily | Harder to alter casually; can be signed and password-protected | Trivial to edit; no protection |
| Password protection | Supported, but most portals reject protected files | Not applicable |
| Typical portal rule | Documents, statements, certificates, multi-page forms | Passport photo, signature, single-page ID card |
Documents with more than one page: PDF
A three-page bank statement uploaded as three JPGs will usually be rejected, either by a form that accepts one file per document or by a reviewer who wants them in order. PDF keeps the pages together, in order, in one file; phone scanning apps and most printers produce it directly. Immigration portals such as New Zealand's state the rule explicitly: documents as a single PDF, photos as JPG.
Keep the PDF plain. Password-protected, encrypted or zipped files are refused by nearly every portal, and PDFs with fillable-form layers sometimes render blank in a reviewer's viewer; "print to PDF" flattens them.
Photos, signatures and one-page IDs: JPG
Anything that is really a picture (a passport photo, a scanned signature, the front of an ID card) belongs in JPG. Portals check pixel dimensions and file size for these, both of which are natural for an image and awkward for a PDF. A JPG can be compressed to exactly 200 KB or 50 KB with the compressors here; a PDF cannot without specialised tools.
Scan at 300 dpi for documents you want readable; 150 dpi is enough for a preview. Save as JPG at 80 to 90% quality, and if the portal allows PDF and the scan is text-heavy, convert the JPG to a PDF so it prints at the right page size.
Size limits
Typical limits are 1 to 5 MB for documents and 100 KB to 2 MB for photos. A phone-camera "scan" of a page is 3 to 6 MB as a JPG straight from the camera; compressing it to 1 MB loses nothing readable. For a PDF that is too large, the fix is usually to re-export it at a lower image resolution (150 dpi, greyscale for text pages) rather than to compress the PDF file itself.
Which should I use?
- If you are…Uploading a multi-page document (statement, contract, transcript)ChoosePDFOne file, pages in order, readable text if OCR was applied.
- If you are…Uploading a passport photo or a signatureChooseJPGPortals check pixels and KB; image tools hit both exactly.
- If you are…Uploading a single ID card or certificate where both are acceptedChooseJPGEasier to compress under the limit and always previews; switch to PDF if the form says "documents as PDF".
- If you are…The form limit is very tight (under 200 KB) for a document pageChooseJPGAn image compressor reaches the target; PDF compression is less predictable.
- If you are…Sending a form you signed and want to keep intactChoosePDFHarder to alter, keeps the page size, prints correctly.
Frequently asked questions
Can I turn several JPGs into one PDF?
Yes; phone scanning apps, macOS Preview, Windows "Print to PDF" and many free tools do it. Put the pages in order first. GivenTool's PDF tools are planned but not yet available.
Why was my PDF rejected as "corrupted" or "unsupported"?
Common causes: password protection, a PDF inside a ZIP, a file renamed from another format, or a PDF/A or form-layer variant the portal's viewer cannot render. Re-export it with "print to PDF" and upload the result.
Which is smaller, PDF or JPG?
For a single scanned page they are similar, because most scanned PDFs are just JPEG images inside a PDF wrapper. A JPG is easier to compress to a precise target; a text-only PDF created from Word is tiny compared with either.
Should scans be colour or black and white?
Colour for anything with stamps, seals, photos or coloured security features (IDs, certificates); greyscale or black and white is acceptable for plain text pages and makes files much smaller. Some assessors require colour scans of originals; check the instructions.