"Message not delivered — attachment too large." Gmail caps attachments at 25 MB, Outlook at 20 MB, and many company mail servers reject anything over 10 MB. Scanned documents blow past these limits easily, because each page is stored as a large image. Here's how to shrink a PDF under the limit in about a minute, free, without installing anything.
Step-by-step: compress a PDF for email
- Open the free PDF compressor.
- Pick a compression level. Start with Balanced — it keeps documents crisp while cutting scans down dramatically.
- Drop in your PDF. Compression starts automatically.
- Check the result: you'll see the before → after size and the percentage saved. Too big still? Click Strong — the same file re-compresses instantly, no need to re-upload.
- Click Download compressed PDF and attach it to your email.
Ready to try it? It's free — no sign-up, no credit card, no watermark, and your file never leaves your device.
Compress a PDF now →Which level should you choose?
- Lossless— rebuilds the file's internal structure without touching quality, and keeps text selectable. Modest savings; ideal for text-based contracts.
- Light / Balanced — re-encodes pages as optimized images. Best quality-to-size trade-off for scans and image-heavy documents.
- Strong — smallest file, ideal when the recipient just needs to read it. Note that the lossy levels make text non-selectable, so use Lossless when the recipient needs to copy text.
Still too big? Split it
A 200-page scan may not fit under a 10 MB cap at any reasonable quality. In that case, use the free PDF splitter to break the document into parts and send them in two or three emails — or extract only the pages the recipient actually needs, which is usually the better answer anyway.
Frequently asked
Will the recipient notice quality loss?
At Balanced, rarely — text stays sharp at reading size. Zooming far into fine print is where Strong shows its trade-off.
Is there a file size limit on the compressor?
No fixed cap. Because compression happens on your device rather than a server, even large files work — speed depends on your computer.
Is my document uploaded anywhere?
No — the file is processed entirely in your browser and never leaves your device.