Per page
—
Free tool
How big will your scanned PDF be?
Color mode and resolution decide whether a 30-page scan is 1 MB or 35 MB. Pick your settings, get a size estimate, and see whether it will email — before you scan the whole stack.
Your scan
Text documents, forms, contracts. Smallest files.
Estimate only — real size depends on how much detail is on each page. Nothing is uploaded.
Estimated size
—
Pick your pages, mode, and quality.
Emails fine?
—
Smaller option
—
Scan it on your phone.
Document Scanner lets you pick color mode and quality, runs OCR on-device, and exports a clean PDF — no upload, no ads, no weekly subscription.
Reference
Roughly how big is one scanned page?
Black & white
Text documents, forms, contracts. Smallest files.
Email ≈ 0.04 MB · Standard ≈ 0.06 MB · High ≈ 0.1 MB per page
Grayscale
Text with light shading, pencil notes, faint receipts.
Email ≈ 0.15 MB · Standard ≈ 0.25 MB · High ≈ 0.45 MB per page
Color
Anything where color matters — IDs, photos, highlighted notes.
Email ≈ 0.3 MB · Standard ≈ 0.6 MB · High ≈ 1.2 MB per page
FAQ
About scan file sizes
Why does scan color mode change the file size so much?
A black & white (bilevel) page stores roughly one bit per pixel, while a color page stores full color per pixel — often 10–30× larger. For text documents, black & white is both smaller and sharper; reserve color for IDs, photos, and pages where color actually carries meaning.
What resolution should I scan at?
About 150 DPI is fine for reading on a screen and emailing; 200 DPI is a good everyday default; 300 DPI is worth it for archival quality and for the most accurate OCR. Going above 300 DPI rarely helps a document and bloats the file.
Does adding OCR make the PDF much bigger?
No. OCR adds an invisible text layer behind the image, which is tiny — usually a few kilobytes per page. The page image is what drives file size, not the searchable text.
Does this tool upload my scan?
No. You enter a page count and pick settings, and it does simple arithmetic in your browser — nothing is uploaded or collected. To actually scan and control quality on your iPhone, Document Scanner runs on-device, so your documents never leave your phone.
Next steps: how to scan documents on iPhone, make a scanned PDF searchable (OCR), or check whether your PDF will email.