Compress a PDF for email

Check the attachment limit for both email accounts, then choose a target slightly below the lower limit. Try lossless compression first for contracts, reports, and invoices.

Mail systems encode attachments for transport, so the message that travels can be larger than the file on your disk.

This tool runs in your browser. Your document is not uploaded.What happens to your files

How should it compress?Lossless — keep the text searchableRewrites the file’s structure only. Text, bookmarks and form fields stay. How much it saves depends on the file. Best for filings that must stay searchable.Hit an exact size limitRecompresses the images inside the file to reach your number, and keeps the text. Images lose some sharpness. If that is not enough, a scan is re-rendered as pictures. A mostly-text document is refused rather than flattened.

Choose a fileProcessed on your device. Your document is not uploaded.

How it works

Check the attachment limit for your account and for the recipient’s.
Choose the PDF and try lossless compression.
If it is still too big, enter a custom target a little below the lower limit.
Consider splitting the document if the recipient will accept more than one attachment.
Open the result and attach that copy to a new message.

Why the sent message is bigger than the file

Email turns binary attachments into a text-safe form, which adds overhead. Signatures, other attachments and the message body can also count toward a total cap. Providers change their rules, so use the limit your own account shows.

Google’s published limit for personal Gmail is 25 MB of attachments in total. PDFOak’s Gmail preset aims for 18 MB to leave headroom. That margin is PDFOak’s own, not a Google rule, and work or school accounts set their own limits.

Compress, or split?

Compression keeps one attachment but can cost image quality. Splitting keeps every page sharp and is usually better for a contract or report, as long as the recipient expects several clearly named parts.

Important limitations

PDFOak cannot see your recipient’s mail policy, so a file that fits yours may still bounce.
Rasterizing a scan in exact-size mode removes its links, forms and text; images in a text PDF are recompressed with those kept.
Some systems count the whole message, not one attachment.

Frequently asked questions

What size should I aim for?

A little under the lower of the two limits, minus room for any other attachments and the message itself.

Is 18 MB Gmail’s limit?

No. Google’s limit for personal accounts is 25 MB of attachments in total. 18 MB is PDFOak’s own preset for leaving headroom.

Use the PDF compressor