Guides
How to compress a PDF on iPhone
Reduce PDF file size on iPhone before email, forms, portals, or messages. Use PDF Toolkit when you also need signing, merge, split, and export controls.
Last updated May 24, 2026
Direct answer
Open the PDF, choose Compress, preview the estimated smaller file size, then export a new copy. Keep the original if the PDF needs print-quality images.
Steps
- Open the PDF from Files, Mail, Safari, or the share sheet.
- Choose the compression tool.
- Pick a compression level based on whether you need screen viewing or print quality.
- Review the estimated file size.
- Export a compressed copy instead of overwriting the original.
- Share the smaller PDF through Mail, Messages, Files, or a web form.
Best compression setting
| Situation | Recommended setting |
|---|---|
| Email attachment limit | Medium compression |
| Upload portal rejects large file | Medium or strong compression |
| Printed contract or scan | Light compression |
| Text-only PDF | Compression may not change much |
Compress PDFs without a weekly subscription.
PDF Toolkit is free to start. Pro unlocks compression, merge, split, reorder, and advanced exports.
FAQ
Can I compress a PDF without uploading it? +
PDF Toolkit is designed for local document workflows. PDFs stay on your device unless you choose to export, share, or use a clearly labeled online feature.
Why did my PDF not shrink much? +
Some PDFs are already optimized. Text-only documents usually shrink less than image-heavy scans.
Can I compress a signed PDF? +
Yes. A common workflow is sign, review, compress, then export the final copy.
Should I delete the original PDF? +
Keep the original when quality, legal records, or future editing matter.