Gmail has a strict 25MB attachment limit — but most files fail before reaching it. This happens because email encoding increases file size during sending. Use the tool above to compress your file below the safe limit instantly.
📋 Gmail Attachment Size Limit (Official Answer)
→Gmail allows attachments up to 25MB per email on personal accounts.
→The 25MB limit applies to the encoded size — base64 encoding adds ~33% overhead in transit, so a 19MB file becomes ~25MB on the wire.
→When a file exceeds the limit, Gmail automatically removes the attachment and inserts a Google Drive download link instead.
→Google Workspace (work/school) accounts may have a different limit set by the administrator.
→To send safely across Gmail, Outlook (20MB), and Yahoo (25MB): compress below 18MB.
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Drop your PDF here to fix upload errors
or click to select file — PDF only
Target size (optional)
targeting 20 MB
⚡ File Size Limits (Quick Fix)
•Gmail's attachment limit is 25MB per email for personal accounts.
•Outlook.com and Hotmail cap email attachments at 20MB.
•Yahoo Mail allows email attachments up to 25MB per message.
•Attachments are base64-encoded in transit, adding ~33% overhead. A 20MB file becomes ~27MB on the wire.
👉 Fix: Compress your file below 20 MB using the tool above.
About this tool
Email attachments are base64-encoded in transit, increasing size by ~33%. A 19MB file becomes ~25MB when sent — right at Gmail's limit. Microsoft Outlook is stricter at 20MB, so files that work in Gmail can still fail there. To avoid errors across all platforms, compress files below 18MB before sending.
How to use this tool
Select or drag and drop your file into the tool above.
Adjust the settings or target size as needed for your specific requirement.
Wait a moment while your file is processed directly in your browser.
Download the final file safely to your device.
💡 Good to know
→Gmail's attachment limit is 25MB per email for personal accounts.Google Help ↗
Gmail allows attachments up to 25MB per email. However, due to encoding overhead, files larger than ~18–20MB may fail to send. If a file exceeds the limit, Gmail automatically uploads it to Google Drive and inserts a download link.Source: Google Help ↗
Why is my email attachment being rejected?+
Most email providers cap attachments at 20–25MB. Gmail and Yahoo allow 25MB; Microsoft Outlook allows 20MB. Compress your PDF below 20MB to ensure it sends on all platforms.Source: Google Help ↗
What is the safest file size for email attachments?+
Under 18MB. This accounts for base64 encoding overhead (~33%) and keeps the total encoded size well below Gmail's 25MB cap and Microsoft Outlook's 20MB cap.Source: Google Help ↗
How do I reduce my email attachment size?+
Compress your PDF using the tool above. This reduces embedded image quality and removes redundant data, bringing the file below the email attachment limit.Source: Google Help ↗
What should I do if I can't compress the PDF small enough?+
Upload the file to Google Drive, OneDrive, or Dropbox and share a link in your email instead of attaching the file directly.Source: Google Help ↗
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