Compress PDF for Email
Choose a preset or set any MB. PDFThin optimizes first for quality, then splits into size-safe parts if the file still will not fit.
Fit-or-split result: get one PDF that fits, or a ZIP of parts under the limit.
Email presets: Gmail 25MB, Outlook 20MB, Outlook.com 25MB, plus custom size.
Private by default: files auto-delete after 60 hours; we don't store document contents in logs.
How it works
Upload
Pick a PDF and a target limit.
Process
We optimize and split as needed.
Share
Download a single file or parts.
Email compression FAQ
What preset should I use?
Gmail allows up to 25 MB and Outlook often allows 20 MB. Choose the closest preset or set a custom target.
Will it split if the PDF is still too large?
Yes. If optimization is not enough, PDFThin splits by size.
Email attachments that actually send
Email limits are tighter than they look
Most email providers publish attachment limits, but the real cap is lower once the message is encoded for delivery. A PDF that looks safe on disk can still fail to send after Base64/MIME overhead is added. This is why a 24 MB file sometimes bounces.
PDFThin keeps a safety margin so the attachment stays under the limit. If you see errors, choose a slightly lower custom size and try again. The goal is predictable delivery, not just a smaller file.
Fit-or-split workflow
We start with lossless optimization: remove hidden bloat, streamline fonts, and compress images when it is safe. Many PDFs shrink without visible changes, so layout and text clarity stay intact.
If the file still will not fit, we split it into ordered parts that each stay under your limit. You get a ZIP of attachments that are ready to send, and page order stays consistent.
Quality controls for scans and images
For scan-heavy PDFs, Smart quality searches for the highest quality that still fits your target. It is especially useful for contracts, receipts, and image-heavy reports.
If you prefer a visual target, use quality presets. If you need a strict size cap, stick with MB presets and let PDFThin optimize and split as needed.
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Compress PDF for email (complete)
Step-by-step workflow for Gmail 25MB and Outlook 20MB limits.
Reduce scanned PDF size
Keep text readable while shrinking scanned documents.
Split PDF by size
Create parts that stay under a target MB limit.
Rotate PDF pages online
Fix page orientation for sideways scans or photos.