Compress PDF for Email Attachments

Shrink PDF files for email attachments. Avoid bounced emails. Gmail, Outlook, Yahoo — all supported. Free online reducer.

Sending a large PDF by email is frustrating — Gmail caps attachments at 25MB, Outlook at 20MB, and many corporate mail servers reject anything over 10MB. Even when the platform accepts the file, large attachments slow down delivery, clutter recipients' inboxes, and often fail silently on mobile. This tool optimizes your PDF for email by reducing file size while preserving reading quality. The result is a smaller, email-friendly document that downloads quickly on any device — all processed locally in your browser.

100% Private

Your PDF never leaves your device. All processing happens in-browser.

Instant Processing

Browser-based compression — no upload wait, no download wait.

Medium Compression

Optimized balance of file size reduction and quality preservation.

Free, no sign-up, works entirely in your browser

How to Compress Your PDF

  1. Click "Open PDF Compressor" above
  2. Upload your PDF file (drag & drop or click to browse)
  3. Select Medium compression level
  4. Click Compress and download the smaller file

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Why You Need to Compress PDF to a smaller size

Sending a large PDF by email is frustrating — Gmail caps attachments at 25MB, Outlook at 20MB, and many corporate mail servers reject anything over 10MB. Even when the platform accepts the file, large attachments slow down delivery, clutter recipients' inboxes, and often fail silently on mobile. Whether it is email attachments or archiving files for long-term storage, keeping your PDF under a smaller size ensures faster delivery and trouble-free uploads. Our browser-based compressor strips redundant metadata, optimises embedded images, and reduces object overhead — all without uploading your file to any server.

Best Compression Settings for Email attachments

For email attachments, the medium compression level gives the best results. Medium compression balances file size and visual quality — text and vector graphics remain crisp while embedded images are moderately reduced. This is the safest option for professional documents. If the result is still too large, try splitting large documents first or reducing the resolution of embedded images.

Complete Privacy — No Server Uploads

Every step of the compression happens in your browser using pdf-lib — the PDF is decoded, optimised, and re-encoded entirely on your device. This makes it safe to compress confidential documents such as financial statements, legal contracts, medical records, and personal certificates. No data leaves your computer, there are no daily usage limits, and you can process as many PDFs as needed in a single session.

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Frequently Asked Questions

What's the maximum email attachment size?

Gmail: 25MB. Outlook/Office 365: 20MB. Yahoo Mail: 25MB. Many corporate servers set even lower limits of 5–10MB. Aim under 5MB for universal compatibility.

Will the recipient see any quality difference?

At medium compression, text is pixel-perfect and images Look virtually identical. Only at high compression might embedded photos show slight quality reduction.

Can I compress multiple PDFs for one email?

Yes — compress each PDF individually, then attach all of them. Or use our PDF Merger to combine them first, then compress the merged file.

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