Free tool
Pick a file or type its size to see which inboxes will take it once email encoding is counted. Only the size is read, in your browser; the file is never opened or uploaded.
Check a file on your device
Only the file size is read, in your browser. The file is never opened or uploaded.
22 MB file, about 30 MB once email encodes it (Base64).
Gmail (25 MB limit)
Too big. Swaps the file for a Google Drive link. Files up to about 18 MB fit.
Outlook.com (25 MB limit)
Too big. Offers a OneDrive link instead. Files up to about 18 MB fit.
Yahoo Mail (25 MB limit)
Too big. Refuses the attachment. Files up to about 18 MB fit.
iCloud Mail (20 MB limit)
Too big. Mail Drop takes over, as a link that expires in 30 days. Files up to about 15 MB fit.
Proton Mail (free) (25 MB limit)
Too big. Refuses the attachment. Files up to about 18 MB fit.
Typical work or school server (10 MB limit)
Too big. Bounces, often hours later, sometimes never. Files up to about 7.3 MB fit.
Too big for some inboxes? Send a link instead.
Upload it once and paste the link into your email. A free Link in Seconds file can be up to 250 MB, and every provider accepts a link. See how to send large files by email or what to do when Gmail says the file is too large.
Get a link for your fileFree: every feature, 50 links, up to 250 MB · Pro: unlimited links, bigger uploads
Most providers cap a message at 25 MB, but that limit applies after Base64 encoding, which makes a file about 37% bigger. So the largest file you can really attach is about 18 MB on Gmail, Outlook.com, Yahoo and Proton free, about 15 MB on iCloud Mail, and about 7.3 MB on a strict 10 MB work server.
Drag in your PDF
From your desktop or phone, any file works
proposal.pdf
2.1 MB
Drop to upload
By the numbers
2,600+
people sharing files
5,100+
links shared
17,400+
times opened
Choose the file from your device, or type its size in KB, MB or GB. Picking a file only reads its size; the contents stay on your device.
Each provider shows whether the encoded file fits its limit, and the largest file it would take. Check the recipient's side too: their server may be stricter than yours.
Upload the file once and paste the link into your email. The message stays tiny, so it never bounces, and the recipient opens the file in their browser.
Email was built for text, so attachments are converted to Base64: every 3 bytes of your file become 4 text characters. That alone adds 33%. The encoded text is then broken into lines of 76 characters, each ending in a line break, and the message carries headers on top. Together that is about 37%, which is why this checker compares the encoded size, not the size on your disk, with each provider's limit.
Your provider's limit is only half of it. The recipient's mail server has its own, and corporate and university servers are often stricter than consumer inboxes, commonly 10 MB. A message that leaves Gmail fine can still bounce at the other end, sometimes hours later, sometimes silently. When you do not know the recipient's setup, plan for the 10 MB row.
A link is a few bytes of text, so it fits every inbox. Upload the file, copy the link, paste it into your email. On Link in Seconds a free file can be up to 250 MB, and you can add a password or an expiry date and see when it was opened.
Step by step guides: send large files via email and what to do when Gmail says the file is too large. The full provider table, with what each one does when you go over, is in email attachment size limits.
Nothing beyond asking your browser for its size. The page uses the browser's File API to read the size of the file you pick; it never reads the contents, never uploads anything, and keeps no record. You can switch off your internet connection after the page loads and it still works.
Still stuck? Ask us directly and a real person answers.
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50 links · 500 MB total · every link feature
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