PDF too large to email? How to reduce its size

When your email says the file is too big, the limit is almost always 20 or 25 MB, and a scanned PDF is usually far heavier than it needs to be. The real limits of the main services and the steps to make it fit, from the simplest to the most drastic.

Reviewed on 3 October 2026 · 4 min read

How much each service allows

The limit depends on who sends and who receives, and the two can differ. This is what the services themselves say in their documentation:

ServiceAttachment limit
Gmail (personal account)25 MB. If you go over, Gmail removes the attachment and adds it as a Google Drive link.
Google Workspace (work or school)Set by the organisation's administrator.
Outlook with internet email accounts (Outlook.com, Gmail…)20 MB; the limit includes the size of the attachment and of the message itself.
Outlook with an Exchange account (business email)10 MB by default, though the administrator can change it.

Two things to keep in mind. First, what counts is the whole message: three 8 MB attachments make 24 MB. Second, limits are also set by the receiver: you can send 20 MB from Gmail and have the recipient company's mailbox reject it because it only accepts 10. If the recipient is a business or an agency, an attachment over 10 MB is a risk even if your own service allows it (Microsoft gives 10 MB as the default for Exchange accounts).

Step 1: compress the PDF

Most PDFs weigh more than they need to, especially scanned ones and ones with photos. Compression re-encodes the images at a lower weight and keeps the text as text. With the PDF compressor you drag the file in and download the reduced version, without uploading it to any server: the compression runs in your browser, which matters if the document is a contract, a payslip or carries your ID. On a scanned PDF the reduction is usually large; on one that is already pure text it is barely noticeable, because it was light to begin with.

If the limit is exact (for example "maximum 10 MB" or "under 2 MB"), use the PDF reducer to an exact size: it tries different quality settings until it lands under the figure you enter. Aim a little under the limit to leave margin, because email adds the weight of the message itself.

Step 2: remove what you do not need

  • Surplus pages: covers, blank pages, appendices nobody asked for. With the split PDF tool you can keep only the pages you need.
  • Oversized images: if the PDF contains photos taken with a phone, each can weigh several megabytes. Shrinking them first with the image compressor and rebuilding the PDF with images to PDF gives you more control than compressing everything at the end.

Step 3: if it is a scan, scan better

A scan at 600 dots per inch (dpi) in colour can weigh far more than one at 200 dpi in grayscale, and for printed text 200 dpi in grayscale is generally enough to keep a document perfectly legible. The practical rule: do not scan at a higher resolution or in more colour than the reader needs, and rescan only the pages that came out too heavy.

Step 4: split it across several emails

If it does not fit even compressed, divide the PDF into two or three parts and send them in separate messages, stating the order in each ("part 1 of 3"). It is less elegant, but it works with any service.

For files that are genuinely big, the most convenient option is to upload them to a cloud service (Google Drive, OneDrive and similar) and send the link. Gmail and Outlook do this automatically when the attachment exceeds the limit. It is the best choice for videos and large folders, with a couple of precautions: set the link so that only the right people can open it (not "anyone with the link" if the content is sensitive), and remember that a recipient's company system sometimes blocks external links.

What about zipping it?

With PDFs and photos it usually helps little. PDFs with images already contain compressed data, and so do JPG and PNG files, so a ZIP saves almost no space. It is useful for bundling several files into one, not for slimming them down. If you need to bundle files, the create ZIP tool does it; but shrink the files themselves first.

Before you send

  1. Open the reduced PDF and look at it at 100% to check that text, stamps and signatures are still legible.
  2. If the document carries a digital signature, compressing it invalidates the signature: send the signed original or check with the recipient.
  3. If it is going to a form or portal with a maximum size, check that portal's exact limit, which may be lower than the email's.

To merge, split or reorder pages first, see merge, split, reorder and rotate a PDF; and to turn photos into one PDF, how to combine photos and images into one PDF.

Sources and further reading

Figures checked on 3 October 2026.

Do it now, free, in your browser. Your files are not uploaded.

Shrink PDF files by recompressing their images, keeping the text selectable.

Compress PDFReduce a PDF to an exact size

Frequently asked questions

What is the maximum attachment size in Gmail?
25 MB for a personal account. If the total goes over, Gmail removes the attachment and adds a Google Drive link. For work or school accounts, the administrator sets it.
What is the attachment limit in Outlook?
According to Microsoft, 20 MB for internet email accounts such as Outlook.com or Gmail, and 10 MB by default for business Exchange accounts. The limit covers the attachment and the message together.
How do I reduce a PDF so I can email it?
Compress it with a PDF compressor that runs in your browser, remove pages you do not need and, for a scan, rescan at lower resolution. If it still does not fit, split it or send a link.
Does compressing a PDF reduce quality?
It lowers the quality of the images somewhat, but with moderate compression the text stays sharp. Check the result at 100% before sending.
Does zipping a PDF make it smaller?
Hardly ever: PDFs with images and JPG files are already compressed, so a ZIP saves very little. It is useful for bundling files, not for shrinking them.
Why does the recipient not get a 15 MB attachment my email let me send?
Because the receiving server sets its own limit. A company or agency mailbox may accept less (for example 10 MB). Reduce the size or send a link.

Related guides

PDFMerge, split, reorder and rotate a PDF without softwareMerge PDFs, delete or extract pages, reorder them, rotate sideways scans and split a PDF in your browser with nothing uploaded, plus what to check first.4 min read Image and photoHow to combine photos and images into one PDFHow to put photos in a single PDF with one page per image: which page size to choose, how to order them, why the file ends up so large and how to shrink it.4 min read Numbers and calculatorsHow many MB in a GB: 1000 or 1024Why 1 GB is 1000 MB or 1024 MiB depending on who measures it, why your 500 GB drive shows 465, and the difference between megabits and megabytes.4 min read

Tools used in this guide

They run in your browser, so nothing is uploaded.

Compress PDFShrink PDF files by recompressing their images, keeping the text selectable. Reduce a PDF to an exact sizeSet the size limit and the PDF is shrunk until it fits, keeping the text if possible. Split a PDFSplit a PDF into several files, choosing where each one starts. Compress images onlineMake photos lighter with a before-and-after view, one or many at once. Convert PDF to PDF/AProduce PDF/A-2B or PDF/A-1B files for archiving and official procedures, privately. Merge PDF filesCombine several PDFs into one, in the order you choose, without uploading them.