Compress PDF
Compress PDF for Email — Fit Under Gmail's 25 MB Limit
Email attachment limits are the #1 reason PDFs get bounced. Gmail caps attachments at 25 MB, Outlook.com at 20 MB, Yahoo Mail at 25 MB, and most corporate Exchange servers cap at 10 MB or less. If your PDF is over the limit, you have two choices: compress it or upload it to a cloud share. Compressing is faster, keeps the email self-contained, and usually preserves enough quality for everyday documents.
- Works in your browser — no install
- Files private and isolated to your workspace
- Free tier covers most everyday use
What you should know
Real attachment limits by provider (2026)
Gmail: 25 MB · Outlook.com / Microsoft 365: 20 MB (Outlook web sometimes 33 MB total mailbox) · Yahoo Mail: 25 MB · iCloud Mail: 20 MB · ProtonMail Free: 25 MB · Most enterprise Exchange: 10–20 MB depending on admin policy.
Most email-bounced PDFs shrink 50–80%
Image-heavy PDFs (scanned documents, design proofs, slide decks exported as PDF) are the easiest to compress. A 60 MB scan often drops to 8–12 MB without visible quality loss. Text-only PDFs are usually already small and compress less.
The 'attachment is over 25 MB' bounce
Gmail measures the encoded attachment size, which is roughly 33% larger than the file on disk because of base64 encoding. So a 19 MB file on disk becomes ~25 MB in transit and may get bounced. Aim for 18 MB or smaller on disk to be safe with Gmail.
Compression vs. quality trade-off
Our default compression preserves text crispness and downsamples photos to 150 DPI — enough for screen viewing and standard printing. For print-grade documents, save the original or run a less aggressive compression pass.
Tips that actually help
- If you're sending a contract for signing, send the link instead of the file — try our send-for-signature tool (10 free/month).
- If your PDF is a scan, run OCR first so the recipient can search the text. OCR doesn't increase file size meaningfully.
- For corporate Exchange (often 10 MB cap), split the PDF and send in two emails or use a cloud share link.
- Dropbox / Google Drive / WeTransfer are good fallbacks if compression isn't enough — but a compressed direct attachment is faster for the recipient.
Compress your PDF for email.
No install, no signup wall, no watermark on paid plans.
Frequently asked questions
What's the maximum email attachment size for Gmail?
25 MB on disk, but base64 encoding inflates that ~33% in transit, so files over ~18 MB on disk can hit the limit. Compress to 18 MB or smaller to be safe.
How do I send a PDF that's larger than 25 MB?
Either compress it (this tool) or upload to Google Drive / Dropbox / OneDrive and send the share link. Gmail prompts you to use Drive automatically when an attachment is too big.
Will compression hurt the quality of my PDF?
For text-based PDFs, no — text stays crisp. For image-heavy PDFs, photos are downsampled to 150 DPI which is fine for screen viewing and standard printing. Save the original if you need a print-grade copy.
Why is my PDF still too big after compression?
Some PDFs are already optimized — try splitting into smaller chunks instead. Or convert to JPG/PNG with our PDF-to-JPG tool, then re-merge only the pages you need.
Is it safe to compress confidential PDFs online?
Files are isolated to your private workspace, encrypted in transit and at rest, and auto-deleted on the free plan after processing. We never share or train on your files.
Related scenarios
Compress PDF
Compress PDF for Upload
Government forms and job portals are notorious for tight upload limits — often half what email allows. USCIS caps document uploads at 6 MB. Most ATS (applicant tracking systems) cap resumes at 5 MB. Visa application portals frequently cap at 2 MB per document. If your PDF exceeds the cap, the form rejects the upload silently or with a useless error like 'file format not supported.' This page is for getting under those caps fast.
Read
Compress PDF
Reduce PDF Size Without Losing Quality
There's an art to PDF compression: shrink as much as possible without making text fuzzy or photos pixelated. Aggressive 'compress everything' tools strip too much and produce visually compromised files. Sensible compression — what we do by default — preserves text rendering, downsamples photos to 150 DPI (fine for screen and standard printing), and strips embedded fonts and metadata that don't change how the PDF looks.
Read
Merge PDF
Merge PDF for Resume
Most job applications expect a single PDF, not a folder of separate documents. Combining your resume, cover letter, and references (or portfolio samples) into one cleanly merged PDF makes you look organized and ensures the recruiter sees everything in the right order. Done badly, it produces a Frankenstein file with mismatched margins and font sizes. Done well, it's a one-page-resume + one-page-cover-letter + supporting-docs sequence that an ATS can still parse.
Read