How to Reduce PDF File Size for Email and Upload Forms

Why are some PDFs so large?

Most of a PDF’s size comes from images. Scanned documents and phone photos saved as PDF contain full-resolution pictures of every page, often 3–5 MB each. Embedded fonts and duplicated images add more. Text itself takes very little space.

That is why compression works best on scanned and image-heavy PDFs, while a text-only PDF exported from Word is usually already small.

Compress a PDF in three steps

1. Open Compress PDF on FreeTools Hub.
2. Choose your PDF and a compression level: Low keeps print quality, Recommended suits email and forms, and Strong produces the smallest file.
3. Press Compress PDF. The page shows the new size and the percentage saved, then download the file.

Which compression level should you choose?

• Low (300 dpi images): for documents you will print.
• Recommended (150 dpi): the best balance for email, job applications and most portals.
• Strong (96 dpi): for on-screen reading when you need the smallest possible file.

Still too large?

If a portal requires a file under 1 MB and Strong compression is not enough, try these steps:

• Split the PDF into smaller parts with Split PDF and upload them separately if allowed.
• Remove unnecessary pages (such as blank backs of scanned sheets) with PDF Page Tools.
• If you are creating the PDF from photos, compress the images first with Compress Image and then use JPG to PDF.
• Scan documents in greyscale at 150–200 dpi instead of full-colour 600 dpi.

Typical results

A 12 MB PDF made from phone photos usually shrinks to 1–2 MB with Recommended compression and below 1 MB with Strong. A 300 KB invoice exported from accounting software is already efficient and may not shrink at all. Large brochures with high-resolution photos often fall by 60–80%.

The page count, text, links and bookmarks are kept. Only images are resampled, so if your document is mostly text, the best way to reduce it further is to remove unnecessary images or pages.

Compressing on a phone

Compress PDF works in mobile browsers. Choose the PDF from Files, Downloads or your email attachments, pick a level and download the smaller file. This is handy when an app or portal rejects a scanned document for being too large.

Will the text become blurry?

No. Compression only resamples images. Text and vector graphics are kept as they are, so typed text stays crisp and searchable even at the Strong level.