Compress PDF for Email Attachments
Email providers impose attachment size limits: Gmail caps attachments at 25MB, Outlook at 20MB, and many corporate email systems limit attachments to 10MB or less. Large PDFs — brochures, portfolios, scanned documents, and reports — frequently exceed these limits and bounce back undelivered. Compressing your PDF before sending takes seconds and ensures your email arrives first time, every time.
Quick Answer
Email providers impose attachment size limits: Gmail caps attachments at 25MB, Outlook at 20MB, and many corporate email systems limit attachments to 10MB or less. Large PDFs — brochures, portfolios, scanned documents, and reports — frequently exceed these limits and bounce back undelivered.
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Your images stay on your device. Nothing is uploaded to any server.
Step-by-Step Guide
4 steps · takes under 1 minute
Check your PDF file size
Right-click the file and check Properties (Windows) or Get Info (Mac) to see the current file size before compressing.
Open the PDF compressor
Navigate to the Compress PDF tool. Upload your PDF — the file is processed locally in your browser.
Choose the right compression level
For email under 10MB: try 'Low' compression first — it's often enough for text-heavy PDFs. For image-heavy files: use 'High' or 'Maximum'. Check the result size before downloading.
Send as an email attachment
Once the compressed PDF is under your recipient's limit (10MB for most corporate email, 25MB for Gmail), attach and send normally.
Before vs After Compression
Typical result on a 1080×1080px product photo
100% Private — Zero Uploads
ImgToolkit runs entirely in your browser using the Canvas API. Your images are never sent to a server, never stored in the cloud, and never seen by anyone else. This makes it safe for sensitive documents, client work, medical imagery, and confidential screenshots.
Pro tip
Pre-optimizing images before uploading to a platform gives you more control than relying on the platform's automatic (and often aggressive) compression.
Format & File Size Comparison
Same 1080×1080px photo processed four ways
| Format | Quality | File Size | Notes |
|---|---|---|---|
| PNG (original) | Perfect | 4.2 MB | No compression — too large for web |
| Compressed PNG | Visually identical | 1.1 MB | −74% — transparency preserved |
| JPG (85% quality) | Excellent | 310 KB | −93% · Best for photos |
| WebP (85%)BEST | Excellent | 205 KB | −95% · Recommended for web |
Based on a 1080×1080px photo. Results vary by image content and complexity.
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Frequently Asked Questions
4 questions answered
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Compress PDF for Email Free