Compress a PDF Under 1 MB for Email

A 30-page scan that should be 800 KB arrives as 24 MB, and the email bounces. PDF size is usually driven by images, not text, so the fix is almost always about how those images are stored.

Why PDFs get so large

• Scanned pages stored as uncompressed or high-DPI bitmaps
• Photos embedded at 600 DPI when 150 DPI is plenty for screen reading
• Duplicate fonts and unused objects left behind by the authoring app
• Layers and editing history that were never flattened

Step 1: try the balanced preset first

Open the PDF Compressor and upload the file. Choose Balanced (ebook) — it downsamples images to roughly 150 DPI and re-encodes them as JPEG, which is the setting that usually lands a scanned document between 300 KB and 1.5 MB while staying perfectly readable.

If the result is still too large, move to Maximum Compression (screen). Text stays sharp because it is vector; only the images lose detail.

Step 2: split the document

If only pages 1–3 are needed, do not send all 40. Use the PDF Splitter to extract the range and compress that. A three-page extract is almost always under 1 MB even before compression.

Step 3: check what you are sending

Open the compressed file and zoom to 100%. If the body text is crisp and signatures are legible, you are done. If photos look blocky, re-run at High Quality (printer) and accept a slightly larger file.

How small can a PDF get?

• Text-only document: 50–300 KB with no visible change
• Scanned contract: 400 KB–1.5 MB at ebook quality
• Photo-heavy brochure: 2–5 MB; consider sending a link instead

Frequently asked questions

Will compression break form fields or signatures?

Interactive form fields survive standard compression. Digital signatures are different: modifying the file invalidates the cryptographic signature, so compress before signing, not after.

Why did my PDF barely shrink?

If the file is mostly vector text, there is little image data to remove. In that case split the document or remove embedded fonts you do not need.

What is the email attachment limit?

Gmail and Outlook accept about 25 MB and 20 MB respectively, but many corporate servers cap attachments at 10 MB or even 5 MB. Aim for under 1 MB if you do not know the recipient's limit.