# How to compress a PDF so it's small enough to email

> Gmail caps attachments at 25MB, Outlook at 20MB. A scanned PDF blows past that in a handful of pages. Here's how to shrink it without retyping anything.

A PDF is almost never too big because of its text. Text is tiny: a 40-page report of plain paragraphs is often under a megabyte. What makes a PDF heavy is images: a page scanned at high resolution, a screenshot pasted in at full size, or a photo dropped into a report without resizing. Each one can weigh several megabytes on its own, and a 10-page scanned contract can easily clear 40MB.

## The limits that actually matter

Email providers cap attachments well below what they let you store. As of this writing, Gmail allows 25MB per message, Outlook.com and Microsoft 365 allow 20MB, and Yahoo Mail allows 25MB. Go over, and the message either bounces back or quietly fails to send, depending on the provider. Company mail servers often set a lower limit than the public ones, sometimes 10MB or less.

## What compression actually does

Compressing a PDF re-encodes the images inside it at a lower resolution and quality, the same trade-off as saving a JPEG at 60% instead of 100%. Text, vector graphics and form fields aren't touched, because they're already compact and lossless. That's why a scanned PDF compresses dramatically (it's almost entirely image data) while a text report barely shrinks at all (there's little left to compress).

[Compress PDF](https://pdfjade.com/compress-pdf) runs this in your browser: pick a level, and it redraws every page's image content at a lower quality before rebuilding the file. Nothing is uploaded to do it, so a contract or a medical scan never leaves your device just to make it smaller.

## If it's still too big

A few scanned pages at very high resolution can resist compression and still land over 20MB. At that point, three options: split the document and send it in two emails with [Split PDF](https://pdfjade.com/split-pdf); scan the originals again at a lower resolution if you still have them (150–200 dpi is plenty for a readable document, see [DPI explained](https://pdfjade.com/guides/dpi-explained)); or share a link instead of an attachment, through whatever cloud storage you already use.

## A quick way to check first

Before compressing anything, open [Count pages](https://pdfjade.com/count-pdf-pages) or just check the file's size in your file manager. If a 5-page PDF is already 30MB, it's almost certainly scanned at an unnecessarily high resolution, and compression will usually cut it to a fraction of that in one pass.

## Questions

### Will compression make my PDF blurry?

At light or medium settings, no meaningful difference is visible on screen, especially for scanned text pages. Push it to the smallest setting and photos can start to show softening or JPEG-style artefacts, so preview the result before sending something that needs to look sharp.

### Does compressing a PDF remove its text or formatting?

No. Compression only re-encodes images. Text stays selectable and searchable, fonts stay embedded, and form fields and links keep working.

### Is there a file size limit on this tool?

No fixed limit. Everything runs on your device, so the practical ceiling is your browser's available memory rather than a server quota.

### Can I compress a PDF on my phone?

Yes, the page works the same in a mobile browser. Very large scans can be slower on an older phone simply because it has less memory to work with.

Source: https://pdfjade.com/guides/how-to-compress-a-pdf-for-email