Quick answer: Open the Compress PDF tool, drop in your file, pick a compression level, and download. Most scanned PDFs shrink by 50–80% — and your document never leaves your browser.
Why your PDF is too large to email
Email providers reject attachments over their limit:
| Email service | Attachment limit |
|---|---|
| Gmail | 25 MB |
| Yahoo Mail | 25 MB |
| Outlook / Hotmail | 20 MB |
| Many corporate mail servers | 10–15 MB |
A scanned document, an image-heavy brochure, or a form with photos can easily hit 20–50 MB. Compression brings it under the limit without re-scanning anything.
How to compress a PDF — step by step
1. Open the compress tool
Go to Compress PDF.
2. Add your PDF
Drag and drop the file. It loads instantly because nothing is uploaded — compression runs locally in your browser.
3. Choose a compression level
- Low — smallest reduction, highest quality (official documents, print)
- Medium — balanced, recommended for most email attachments
- High — maximum reduction (quick-reference documents, drafts)
4. Download and send
Click Compress, download the result, attach it to your email. Done.
Typical results
| Document type | Original | Compressed | Reduction |
|---|---|---|---|
| Scanned ID copy | 8.5 MB | 1.2 MB | ~86% |
| Scanned application form | 15 MB | 3.8 MB | ~75% |
| Property/legal documents | 22 MB | 5.1 MB | ~77% |
| Slide deck with images | 35 MB | 8.4 MB | ~76% |
Text-heavy PDFs (like resumes) compress less — 20–40% — because text is already stored efficiently.
Does compression reduce quality?
- Low/Medium — text stays sharp; images lose a barely noticeable amount of detail
- High — visible image softening, but text remains readable
- Text-only PDFs — virtually no visible change at any level
Tip: for documents going to banks, courts, or government offices, stick to Low or Medium.
If compression alone isn't enough
- Delete unneeded pages first with Delete Pages
- Remove embedded attachments with Edit Attachments
- Convert to greyscale with PDF to Greyscale — color scans shrink dramatically
- Split the file with Split PDF and send in two emails
- Strip metadata with Remove Metadata for a small extra saving
Frequently asked questions
Will compression change my PDF's content? No. Text, layout and structure stay identical — only image data is re-encoded.
Can I compress on my phone? Yes, CommandPDF runs in any mobile browser. No app required.
Is my document safe? Yes — compression happens entirely on your device. The file is never uploaded, so there's no server copy to worry about.
Can I compress an already-compressed PDF? Yes, but expect a smaller reduction the second time.
Conclusion
Compressing a PDF before emailing takes under a minute and usually cuts the size by more than half — enough to clear any attachment limit.
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