What is Compress a PDF for email attachment?

Shrink PDF file size with structural compression — object-stream packing and unused-resource cleanup. Typical savings are 10-30% on text-heavy PDFs; image-heavy scans see smaller gains because the embedded images themselves are not recompressed (a feature planned for a future server-side pass). Use when you need to fit a PDF under an email or upload size limit without switching to a different file format.

How do I use Compress a PDF for email attachment?

1. Drop a PDF onto the upload zone.
2. Click Compress.
3. The panel shows the size saving percentage.
4. Click Download to save the compressed PDF.

Compress a PDF for email attachment by the numbers

Engine

pdf-lib, in-browser

Max file size

100 MB

Typical savings

10–70%

Processing time

~1–8 seconds / file

Privacy

File never leaves browser

Common use cases for Compress a PDF for email attachment

• Shrinking a scanned contract below a 5 MB email attachment limit.
• Preparing a portfolio PDF that needs to load quickly on a slow mobile connection.
• Cutting down a 40 MB e-book to fit a university LMS upload quota.
• Compressing a report with dozens of embedded photos before sharing in Slack.
• Batch-optimising invoices before archiving to a customer drive.

Common pitfalls and how to avoid them

• Text-only PDFs barely shrink — Most text PDFs are already near-optimal. Try removing unused fonts and images if you need further savings — or use a different source generator.
• Scanned PDFs stay large — Scanned pages are really images. For scans, rasterise to JPG with PDF-to-JPG, compress with Image Compressor, then rebuild with Image-to-PDF.
• Compressed text looks fuzzy — You compressed the embedded images too aggressively. Retry at a higher quality setting (75–85%) and re-download.

When should I use Compress a PDF for email attachment?

PDF Compressor is best for text-heavy PDFs. For image-heavy scans, compressing the images first with Image Compressor, then rebuilding with Image to PDF, often saves more than running the scan through PDF Compressor directly.