What the email limits actually are

Google's help page says that for personal Gmail accounts the limit is 25 MB, and that for work and school accounts the Google Workspace administrator sets the limits. When a Gmail attachment goes over the limit, Gmail adds it as a Google Drive link in the message instead. Microsoft's Outlook.com support page gives the limit for an email as 25 MB, including text and all inserted and attached files; OneDrive links do not count towards it. Some older Microsoft articles quote 20 MB and a lower default for business Exchange accounts, so a company mailbox may well have a smaller cap than a personal one.

Treat those numbers as ceilings, not targets. Attachments are encoded for sending, which makes the message larger than the file, so a PDF close to 25 MB can still be rejected. Many online forms and portals set much lower limits, commonly a few megabytes. Aim well under whichever limit applies, and check the real size in your file manager. Sizes in WORDMIO use decimal units, where 1 MB is 1,000,000 bytes; what 100 KB means explains this.

Why is the PDF so big?

Text is small. A PDF of plain typed pages is often well under a megabyte. Size comes from images: phone photos and scans of pages can each be several megabytes, and a PDF stores them at whatever size they were inserted. Ten full-resolution photos can easily reach tens of megabytes.

You can tell which kind you have by selecting text in the PDF. If you can highlight words, it is probably typed content with some images. If you cannot, each page is a picture, and the number of pages multiplied by the image size explains the weight.

Fix 1: rebuild the PDF from smaller images

This is the most effective route when you still have the original photos or scans.

  1. Shrink each picture with Compress image. If the pictures are far larger than needed, also reduce their dimensions with Resize image.
  2. Zoom into the smallest printed text on the result to make sure it stays readable.
  3. Put the smaller pictures back together in order with Images to PDF.
  4. Check the new file size.

Be aware of the trade-off: the new PDF is image-based, so its text is not searchable. And this does not shrink an existing PDF directly. If you only have the PDF, not the source images, use one of the other fixes.

Fix 2: send only the pages that are needed

People often attach a 60-page file when they were asked about three pages. Extract just those pages with Split PDF, entering something like 12-14. The smaller result will not carry the full weight of the rest. To remove pages from the inside of a file, use Organize PDF. This is usually the quickest fix and also keeps unrelated information private, though the pages you keep are not redacted.

Fix 3: split it and send in parts

If the recipient needs everything, divide the PDF into pieces that each fit the limit, for example pages 1-30 and 31-60, using Split PDF's page selection (the file can be up to 20 MB and 400 pages). Number the files clearly, such as Report-part-1-of-2.pdf, and say in the email how many parts are coming. The recipient can join them with Merge PDF if they want one file. See also splitting a large PDF.

Merging makes it bigger, not smaller

Merge PDF does not compress, so the combined file is about as large as the inputs added together. If you are combining documents for a size-limited upload, trim first: extract only requested pages, shrink photos before turning them into pages, and leave out anything optional. Merge PDF accepts up to 100 MB of input and produces up to 100 MB of output, which is far above typical email limits.

Before you hit send

  • Check the final size in your file manager, not by guessing.
  • Open the PDF and read the smallest text on each page.
  • Make sure the pages are in the order the recipient expects.
  • Use a clear filename.
  • If the file is for an upload form, check its stated limit with Upload check rules in mind, and see job application email attachments for what employers usually expect.

Frequently asked questions

What is the maximum PDF size I can email?

Google states 25 MB for personal Gmail accounts, and Microsoft gives 25 MB for Outlook.com. Work and school accounts can have different, often lower, limits set by an administrator.

Can WORDMIO compress an existing PDF?

No. WORDMIO has no PDF compression. You can rebuild the PDF from compressed images, extract fewer pages, or split it into parts.

Why is my PDF over 25 MB when it only has a few pages?

Pages made from phone photos or high-resolution scans store large images. A few such pages can add up to many megabytes.

Is a link better than an attachment?

It avoids size limits, but you must control who can open the link. For private documents, restrict access to named people.

Put it into practice.

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