PDF JustFit Download
Guide

How to Compress a Scanned PDF

Short answer: To compress a scanned PDF, open the document in PDF JustFit, enter the target size you need, and compress. Scanned pages are usually image-heavy, so Maximum compression rasterises pages when the smallest possible file is required.

When you need this

  • A scanned document is far larger than the same document would be as a digital export.
  • A scanned contract or ID copy needs to fit an attachment limit.
  • You want to reduce a multi-hundred-page scan.
  • You need the scan small enough to upload to a portal.

Steps

  1. Open the scanned PDF in PDF JustFit

    Load the document from Files or send it from another app.

  2. Let OCR run

    Scanned pages are OCR-recognised automatically, so the document gains a text layer as it is processed.

  3. Enter a target size

    Type the size you need. A 50 MB scan can often be brought far below that.

  4. Choose the mode

    Smart keeps text selectable. If the target is very tight, Maximum rasterises pages for the smallest possible file.

  5. Compare and export

    Check the before-and-after comparison, then export or share the result.

Built for scans specifically

The PDF JustFit product description calls out scanned documents directly. Very large scanned documents are handled page by page so that memory stays under control, which matters on a phone or tablet.

OCR and compression together

Because OCR runs automatically on scanned pages, you do not have to choose between a searchable document and a small one — you can have both, then compress to the size you need.

Privacy and limitations

Very tight targets reduce detail

Scanned pages are images, so reaching a very small target means stronger image compression. Check small print and fine detail after compressing.

Already-optimised scans

If a scanned PDF is already fully optimised, PDF JustFit keeps your original file rather than producing something larger.

Frequently asked questions

Why are scanned PDFs so large?

A scanned PDF stores each page as a high-resolution image. Images take far more space than text, so a scan of a text document is much larger than a digital export of the same document.

How do I compress a scanned PDF?

Open the scanned PDF in PDF JustFit, enter the target size you need and compress. If the target is very tight, Maximum compression rasterises pages to reach the smallest possible file.

Download on the App Store

Related pages

PDF JustFit features

Exact-Size CompressionSet an exact target PDF size — for example 2 MB for an email attachment — and let PDF JustFit search for the best possible quality automatically.Maximum CompressionMaximum compression in PDF JustFit rasterises pages to produce the smallest possible file, ideal when a hard size limit must be met.Smart CompressionSmart compression in PDF JustFit reduces file size while keeping text, fonts and document structure fully selectable.PDF OCRExtract text from any PDF and automatically OCR scanned pages so scanned documents can be searched, indexed and queried.

Problems this solves

PDF Is Too LargeWhat to do when a PDF file is too large — why PDFs grow, and how to reduce one to a size that works.PDF Is Too Large to UploadWhen a website or portal rejects a PDF for exceeding its size limit, here is how to bring the file under the cap.Scanned PDF Is Not SearchableWhy scanned PDFs cannot be searched or copied, what OCR does, and how to make a scanned document searchable.I Need to OCR a PDFWhen you need to extract text from a PDF — including a scanned one — and how OCR fits into the rest of the workflow.

Guides

Sources

Last verified:

Keep your documents light, organized and private

PDF JustFit: Compress, AI Chat is available on the App Store for $9.99. Requires iOS/iPadOS 26.5 or later.

Download on the App Store Explore PDF tools