How to Reduce PDF File Size for Email

The limit applies to the whole message, and attachments grow by roughly a third when they are encoded for sending, so aim comfortably below the number you see here.

• Gmail: 25 MB per message. Larger files are offered as a Google Drive link instead.
• Outlook.com and Microsoft 365: 20 MB by default, though your organization may set it differently.
• Yahoo Mail: 25 MB per message.
• Company and school mail servers: often 10 MB. If you are writing to an organization, 10 MB is a safe target.

Text is tiny: a 100-page report of plain text is often well under 1 MB. The weight comes almost entirely from images. Scanned documents are photographs of paper, often saved at 300 dots per inch or more. Reports built in Word or PowerPoint frequently contain photos pasted in at full camera resolution, even when they are displayed at the size of a stamp. Embedded fonts add a little more on top.

That is why compression works so well: it lowers the resolution of images to what a screen actually needs and re-encodes them efficiently, while leaving text as sharp as before.

1. 1

   Open the compressor

   Go to Compress PDF and drop in your file. No account is needed.

2. 2

   Pick the Ebook setting

   Ebook (150 DPI) is the best balance for email: text and charts stay crisp on any screen and in normal office printing. Choose Screen (72 DPI) if you need the smallest possible file and the reader will only view it on screen.

3. 3

   Check the result

   The tool shows the new size and how much you saved. Open the downloaded file and zoom in on a page with small print or a photo to make sure it still looks right.

Very long scanned documents can stay large even after compression. You have a few options, and they combine well:

• Send only what is needed. Use Split PDF to pull out the relevant pages, or split a long file into two or three parts and send them in separate emails.
• Try the Screen preset. For documents that will never be printed, 72 DPI is usually still readable.
• Rescan at a lower resolution. If you control the scanner, 150 to 200 DPI in grayscale is plenty for text documents and produces far smaller files than 300 DPI color.
• Share a link instead. For very large files, cloud storage links (Google Drive, OneDrive, Dropbox) avoid attachment limits entirely.

Not if you pick the right preset. Compression changes images, not text, so letters stay perfectly sharp at any zoom. Photos become slightly softer at lower settings, which is rarely noticeable on screen. If the PDF will be professionally printed, use the Printer preset instead and accept a smaller saving.

Drible compresses with Ghostscript on our server. The file is deleted as soon as the compressed version is sent back to you, and we always return whichever version is smaller, so compressing can never make a file worse.