PDF Medic OnlineMake a PDF small enough to email
Too large to send? Get a PDF under the Gmail or Outlook attachment limit — the box below is set for 10 MB work accounts.
Files never leave your device
How to Compress PDF for email
- Press Choose a PDF, or drop it on the box above. It is compressed in your browser, not on a server.
- Fit a size is set to 9500 in Must be under (KB), which suits a 10 MB work account. If you send from a personal Outlook.com account in Outlook, you can type 19000; from personal Gmail, 24000.
- Press Compress PDF.
- Press Download and attach the new file to your email. Its name ends in -compressed.
The limits, from Google and Microsoft
These are the numbers the two companies give in their own help pages, checked on 7 October 2026:
- Gmail, personal accounts: 25 MB (Google’s Gmail Help). If the attachments add up to more, Gmail takes them off the email and puts in a Google Drive link instead. For work or school Gmail, the limit is set by the organization’s administrator.
- Outlook with an internet account such as Outlook.com, or Gmail added to Outlook: 20 MB (Microsoft Support).
- Outlook with an Exchange account, the usual work email: 10 MB by default (Microsoft Support). An administrator can set a different number, so if your company has its own rule, that one counts.
Why the box says 9500
You often don’t know which kind of account you, or the person you write to, are using. 9500 KB is 9,728,000 bytes: under 10 MB whichever way it is counted, with some room left for the email itself. So 9500 is the safe choice for the strictest common limit.
If you know you are sending from a personal account, a higher number lets the tool keep more quality. Type 19000 for Outlook.com (19,456,000 bytes, under Microsoft’s 20 MB) or 24000 for personal Gmail (24,576,000 bytes, under Google’s 25 MB). In our test, a PDF of ten detailed photos came to about 9.4 MB at Best quality. With 9500 in the box that was just too big, so the tool dropped to Balanced, about 3.4 MB. With 19000 or 24000 it would stay at Best quality.
The whole email counts, not one file
Microsoft says its limits cover all the attachments together, plus the email itself. Two PDFs of 6 MB each make 12 MB, which a 10 MB work account will refuse even though each file is under 10 MB. Share the room out instead: for two files on a work account, type about 4700 for each.
There is also a hidden cost. To travel by email, attachments are turned into text, which makes them roughly a third bigger, and some mail systems measure that larger size. The person you are writing to may also have a lower limit on their side. If an email bounces even though your file was under the limit, try a smaller number or the next step below.
Still too big? Send it in two emails
If even Smallest is over the limit, split the file. In Split PDF, choose Every few pages and type how many pages go in each file, or use Take out pages twice, once for each half. Compress each part here and send one per email. The person who receives them can put them back together with Merge PDF.
If the PDF holds private details, you can lock it with a password in Protect PDF, and tell the password by phone or text rather than in the same email. Compress first and protect last: Compress PDF refuses files that have a password.
Everything happens in your browser: your file is never uploaded to any server. You can check: once your file is open, turn on airplane mode — the tool still works.
Questions
How do I make a PDF small enough to email?
Choose it on this page, keep Fit a size with 9500 in the box (or type 19000 for Outlook.com, 24000 for personal Gmail) and press Compress PDF. Attach the downloaded file instead of the original.
What is the attachment size limit in Outlook?
Microsoft says 20 MB for internet accounts such as Outlook.com, and 10 MB by default for Exchange work accounts. Both count all attachments together with the email.
What is the attachment limit in Gmail?
Google says 25 MB for personal Gmail accounts. Bigger attachments are replaced by a Google Drive link. Work and school accounts have limits set by their administrator.
Why does my email still bounce when the PDF is under 10 MB?
Other attachments and the email itself count too, attachments grow on the way, and the receiver may have a lower limit. Compress to a smaller number, or split the PDF into two emails.
Can I put a password on the PDF before emailing it?
Yes, with Protect PDF. Do it after compressing, because Compress PDF does not accept password-protected files.
Is my file uploaded?
No. Compress PDF for email runs in your browser on your own device. The file is never sent to our server or anyone else. Once your file is open you can even turn on airplane mode.
Is it free?
Yes. No sign-up, no limits on how many files, and no watermark is added to your file.
Does it work on a phone?
Yes, in any modern browser on iPhone, Android, Mac, Windows or Linux. Very large files work best on a computer, because a phone browser has less memory.