How to make a scanned PDF smaller on your phone

When a form says "maximum file size 2 MB", ScanMojo can make a smaller copy of your scan on the phone itself, so the file never goes to a website to be compressed. Making and previewing the smaller copy is free; sharing it is part of ScanMojo Pro, and your original scan stays as it is.

This is a ScanMojo Pro tool: $39.99 a year with a 7-day free trial, or $6.99 a month (U.S. prices). Scanning and PDF export stay free.

  1. 1

    Open the scan

    The size it would be as a PDF shows in the corner of the page, like "PDF · 4.2 MB". Tap it, or tap Share › Smaller PDF.

  2. 2

    Pick how small

    Choose Standard (clear on screen and in print), Small (for email and most upload forms), or Size Limit and pick Under 500 KB, 1 MB, 2 MB, 5 MB or 10 MB.

  3. 3

    Check the preview

    You see the old size crossed out next to the new one, and the smaller pages themselves. Look at the smallest print to make sure it still reads.

  4. 4

    Leave pages out if you need to

    On a scan with several pages, tap a page's thumbnail to leave it out of the copy, and tap it again to put it back. Fewer pages keep the rest sharper.

  5. 5

    Share it

    Tap Share and upload or attach the smaller PDF. Your scan in ScanMojo isn't changed.

Nothing is uploaded

Most "compress PDF" results are websites that ask you to upload the file first. For an ID, a bank statement or a medical letter, that's one more copy of it on someone else's server. ScanMojo makes the smaller copy on your phone, and it works without a connection.

Your scans stay on your phone unless you share them or turn on sync to your own iCloud Drive or Google Drive.

If it won't go small enough

Each page's picture is stored again with fewer pixels and more compression. If small print starts to blur, ScanMojo says so. If even the smallest version is over the limit, it tells you that too: leave some pages out, or send the document in two parts.

When you scan for a form with a tight limit, the B&W or Gray look on text-only pages helps as well.

Still searchable

The smaller PDF keeps the text ScanMojo read on each page, so whoever receives it can still search it and copy from it.

Questions

Is compressing a PDF free in ScanMojo?

Making the smaller copy and previewing it is free, so you can see the size and check it reads. Sharing it is part of ScanMojo Pro. Scanning and sharing the regular PDF stay free, with no ads and no watermark.

Can I compress a PDF without uploading it?

Yes. ScanMojo makes the smaller copy on your iPhone or Android phone, so the document isn't sent anywhere to be compressed.

How small can it go?

The size limits are under 500 KB, 1 MB, 2 MB, 5 MB and 10 MB. How small a document can go depends on how many pages it has; leaving pages out helps most.

Does it change my original scan?

No. Smaller PDF makes a copy to send. The scan in ScanMojo stays at full quality.

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