Compression
5 Ways to Make a PDF Smaller for Email (2025 Guide)
Gmail, Outlook, and ATS platforms reject bloated attachments. This guide shows five workflows to shrink PDFs so they always send on the first try.
Table of contents
Know your email provider limits
Before shrinking anything, confirm the size ceiling of the platform you are using. Gmail and most consumer providers cap attachments at 25 MB, while many corporate Exchange servers use a stricter 10 MB limit. Job portals, visa systems, and scholarship sites often require files under 5 MB. Record those thresholds so you compress with purpose instead of guessing.
If you frequently email the same organization, ask their IT manager for confirmation. Document the answer inside your workflow guide to avoid fire drills when deadlines hit.
Try the tools mentioned in this guide
Every workflow here is powered by MyPDFHero. Jump straight into the tool that fits your task.
Compress PDF
Shrink assignments, contracts, or reports to fit email and LMS limits.
Open tool →Merge PDF
Combine chapters, receipts, or scans before submitting a single file.
Open tool →JPG to PDF
Turn photos, scans, or screenshots into polished PDFs in seconds.
Open tool →Method 1: Compress PDFs inside MyPDFHero
The fastest option is the Compress PDF tool. Drop your file, wait for the smooth progress bar, and download a new file that typically lands between 0.5 MB and 3 MB. Because the tool deletes uploads automatically, it is safe to use with HR paperwork or legal appendices.
For recurring tasks, bookmark the compressor and pre-fill your browser with notes about each submission. This minimizes context switching and speeds up compliance workflows.
Method 2: Export a lighter PDF from the source app
If you still have the original document in Word, Keynote, Google Slides, or Canva, export again with PDF/X-1a or “Minimum size” options. These presets subset fonts and downsample imagery before a PDF even hits your drive. Pair this with the MyPDFHero compressor for the smallest possible file.
Designers can go a step further by flattening transparent PNGs and removing unused artboards. Every megabyte saved upstream means less work downstream.
Method 3: Split large PDFs
Sometimes the smartest solution is to send two attachments. Break the PDF into logical sections—perhaps chapters, appendices, or invoice bundles—then label each part clearly. Most inboxes handle multiple smaller attachments better than a single bloated file.
Use Preview on macOS or any PDF editor to drag pages into new documents. After the split, run each file through MyPDFHero for good measure.
Method 4: Use cloud sharing when allowed
If policy permits, upload the heavy PDF to Google Drive, Dropbox, or OneDrive, then share a restricted link. This bypasses attachment limits entirely while keeping recipients secure behind sign-in walls. Always double-check whether the recipient’s organization blocks external links before relying on this tactic.
When linking externally, provide a short explanation inside the email so reviewers know the file is safe and intentional.
Method 5: Print to PDF to flatten extras
Some PDFs contain hidden layers, forms, or embedded media. Printing to PDF flattens everything into a simpler file, often shaving off megabytes. After printing, compress the new file to reach your target size.
This approach works wonders for files exported from design tools that include unneeded metadata or ICC profiles. Just keep an eye on links or form fields that may disappear after flattening.
Document every send
Log the original size, compressed size, and destination each time you email documents. This institutional knowledge helps you troubleshoot future rejections quickly. If you operate within a compliance-heavy company, this log also proves that you follow data-handling best practices.
Store the log inside a shared workspace or knowledge base so colleagues can replicate your success without relearning the workflow from scratch.
Step-by-step workflow
Follow these practical steps inside MyPDFHero or your operating system to complete the task quickly.
Step 1
Check the attachment limit
Verify the maximum size your recipient accepts before you start shrinking files.
Step 2
Compress or split as needed
Use MyPDFHero, desktop exports, or splitting techniques to get under the target size.
Step 3
Rename the optimized file
Add “-compressed” or the destination name so you never confuse versions.
Step 4
Attach and verify
Upload the new PDF to your email draft and confirm it remains below the limit.
Step 5
Log the workflow
Record the details inside your tracking sheet for faster approvals later.
Official resources
Validate your workflow with trusted documentation from Google, Microsoft, Adobe, and other official sources.
- Gmail attachment FAQ
Confirms Google’s size and file-type rules for attachments.
- Outlook/Exchange attachment guidance
Microsoft’s official answer for administrators and end users.
- Dropbox file sharing security overview
Use this when you pivot to link-based sharing rather than attachments.
Frequently asked questions
What is the maximum attachment size for Gmail?
Gmail caps attachments at 25 MB total per email. Anything larger is automatically uploaded to Google Drive.
How do I email a PDF that is 30 MB?
Compress it first, split it into multiple files, or upload it to cloud storage and share a link. Email providers will reject the upload otherwise.
Does Outlook have the same limit as Gmail?
Not always. Outlook and Exchange admins set custom thresholds. Many organizations stick to 10 MB to conserve bandwidth.
Is it safe to send compressed PDFs?
Yes, as long as you use a trusted tool like MyPDFHero that transmits files over HTTPS and deletes them quickly.
Should I password-protect compressed PDFs?
Use passwords only if policy requires it. Keep in mind that extra protection adds friction for the recipient and complicates merging later.
Can I automate emailing compressed PDFs?
You can pair MyPDFHero with automation platforms that watch a folder and send an email once the compressed file lands there.
Related reading
Expand your PDF toolkit with more long-tail guides from MyPDFHero.
How to Compress a PDF Without Losing Quality (Free Guide)
A practical tutorial that shows you how to reduce PDF size without hurting readability, perfect for email, admissions, or procurement portals.
Read more →How to Reduce PDF Size Below 1 MB (or 500 KB)
This tutorial covers the exact steps to get under strict upload limits, including advanced flattening, image replacement, and compression tactics.
Read more →PDF Too Large to Upload? Here’s How to Fix It
Covers emergency fixes for admissions, visas, payroll, or LMS portals that refuse a PDF because it exceeds their threshold.
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