Compress PDF to 10 MB
Shrink a big scan or report to under 10 MB for an upload portal or a work email capped at 10 MB. If it already fits, you keep your original. Free, no upload.
Shrink a big scan or report to under 10 MB for an upload portal or a work email capped at 10 MB. If it already fits, you keep your original. Free, no upload.
To compress a PDF to 10 MB, SafeResize turns the pages into lighter pictures until the file is 10,000,000 bytes or less, which is under 10 MB whether a website counts 1 MB as 1,000,000 or 1,048,576 bytes.
| 10 MB in bytes | 10,000,000 bytes, or 10,485,760 bytes when 1 MB is counted as 1,024 KB, as Windows does |
|---|---|
| 10 MB in KB | 10,000 KB, or 10,240 KB as Windows counts |
| Each page gets, shared evenly | About 1 MB with 10 pages, or 250 KB with 40 |
| Sharpness of each page | 150 DPI first, then 120, 96, 72, 56 and 45 DPI, stopping at the first that fits |
| Who asks for 10 MB | Upload portals such as NIU's Graduate School application ("Files must not exceed 10 MB"), and work email: Outlook with an Exchange mailbox stops at 10 MB (10,240 KB) by default |
Sources, checked 5 Oct 2026: NIU's file upload requirements and Microsoft's Outlook support article.
A limit of 10 MB is common on upload portals and for work email. The application portal of NIU's Graduate School, for example, says "Files must not exceed 10 MB", and Outlook stops at 10 MB by default for a work (Exchange) mailbox. A PDF goes over 10 MB when it holds many scanned pages, or photos saved at full size.
This page opens the PDF tool with 10 MB filled in. If your PDF is already under 10 MB, the tool says so and you keep your original, with its text still selectable. Otherwise it saves each page again as a lighter picture, starting at 150 DPI, until the whole PDF is under 10,000,000 bytes, which is under 10 MB however a website counts.
We tried this page on a laptop with a sample scan of 40 pages, about 18 MB in all, or 470 KB a page. It came out at about 9.2 MB, still at 150 DPI, in about 13 seconds. The tool only had to lower the picture quality of each page, not the sharpness.
Shared evenly, 10 MB (10,000,000 bytes) gives each page about:
Add the PDF on this page: 10 MB is already filled in. Press "Make it this size". The tool keeps the pages at 150 DPI if it can and lowers only the picture quality; it lowers the sharpness only if the file is still too big. In our test, a 40-page scan of about 18 MB came out at about 9.2 MB, still at 150 DPI.
Both are in use. Windows counts 1 MB as 1,024 KB, so it says 10,240 KB, and Microsoft writes Outlook's limit the same way. Many websites count 10,000 KB. SafeResize keeps the file under 10,000,000 bytes, which passes both.
No. Each page is rebuilt as a picture, so a digital signature is not kept, and the new PDF is never locked with a password. Some portals refuse both anyway: NIU's Graduate School, for example, takes no password-protected PDFs and no PDFs with a digital signature. If a signature must stay valid, keep your original.
Not when you type 10 MB. A PDF over 10 MB comes out under it, or the tool says it could not get there and shows the smallest size it made. A PDF already under 10 MB is not changed at all. Only the Small, Medium and Large cards can be bigger than your file, and then they say "Not smaller than your file".