Compress PDF for Email
Shrink big PDFs for email and upload limits, with an optional target size in KB.
- ✓Files never uploaded
- ✓No file limits
- ✓No sign-up
- ✓No watermark
Email providers limit attachment sizes: Gmail allows about 25 MB per message, Outlook.com about 20 MB, and many company mail servers only 10 MB. And because attachments are encoded when sent, a file can hit the limit even if it looks slightly smaller on disk. When your PDF bounces or gets turned into a cloud link you didn't want, compressing it is the simplest fix. This page opens the compressor with settings that aim for a comfortable email-friendly size.
Drop your PDF, click Compress PDF, and download the smaller copy to attach. Scans, photo-heavy brochures and documents created on a phone camera benefit most — a 40 MB scan often ends up just a few megabytes. If you want to be sure it fits under a particular limit, type a target size in KB, such as 9000 for a 10 MB company server. Smaller attachments also send faster and are kinder to recipients reading on mobile data.
One thing to know: the compressor re-renders pages as optimized JPEG images, so text in the compressed file won't be selectable. That's perfect for sending a scan or a signed form, but if the recipient needs to copy text from a report, consider splitting it into two emails with Split PDF instead. Your document is processed entirely in your browser — it's never uploaded, which is exactly what you want for payslips, contracts or medical records that you're about to email to someone you trust.
If the document is still too large even after strong compression, consider splitting it into two or three parts and sending them in separate emails, each clearly labelled part 1, part 2 and so on.
How to Compress PDF
- 1Drop your PDF into the box or click to choose it.
- 2Pick a compression level: low, medium or high.
- 3Optionally enter a target size in KB, such as 500.
- 4Click Compress PDF and the smaller file downloads automatically.
Why pdfdots?
Private by design
All processing happens locally in your browser. Your documents are never uploaded to a server, so nobody else can see them.
No limits
No daily task caps, no file-count limits and no premium tier. Process as many PDFs as your device can handle.
Fast
There's no upload or download queue. Work starts the moment you drop a file and finishes at the speed of your own computer.
Works everywhere
Windows, Mac, Linux, iPhone, Android or Chromebook — if it has a modern browser, pdfdots runs on it. Nothing to install.
What the compression levels actually do
pdfdots compresses a PDF by re-drawing each page as an optimized JPEG image and building a new PDF from those images. This is very effective on the files that are usually the biggest problem: scanned documents, phone photos of paperwork and PDFs full of high-resolution pictures. A 20 MB scan often drops to a small fraction of that size. Low keeps the most detail, medium is a good balance for most documents, and high produces the smallest file with visibly softer images.
There's an honest trade-off to know about. Because pages become images, text in the compressed file is no longer selectable or searchable, and links stop being clickable. For a scanned document that doesn't matter — it was an image anyway. For a text-heavy report exported from Word, compression may not shrink it much and you'd lose the selectable text, so keep the original as well.
If you have a hard limit, such as a portal that only accepts files under 500 KB, type that number in the target size field. The tool then tries progressively stronger settings to get the file at or under the target. Very long documents may not reach extremely small targets while staying readable; in that case, split the file or remove unneeded pages first. Everything runs on your own device, so even confidential documents are never uploaded.
Our take
Compress PDF is our go-to when an upload form has a hard limit, typically a job portal, a university application or a government site that refuses anything above a few hundred kilobytes, and the file in hand is a phone scan.
We start with Medium, because it keeps printed text readable while cutting most scans dramatically. When a portal names an exact limit we type it into the target size field, a little below the stated maximum, so small overhead does not push the file over. High is our last resort for long scans.
The trap: compression turns every page into a JPEG, so a text-based report loses selectable text and may barely shrink. For those files we would rather remove unneeded pages with Remove Pages, or re-export from the original program, and keep the searchable version.
Popular uses
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Frequently asked questions
What size should a PDF be for email?+
Under 10 MB is safe for almost any mail server. Gmail allows about 25 MB and Outlook.com about 20 MB per message.
Why does my email bounce even though the file is under the limit?+
Attachments grow by roughly a third when encoded for sending, so aim well below the stated limit.
Can I set an exact size?+
Yes. Enter a target size in KB and the tool tries to get the file at or below it.
Is it safe for confidential documents?+
Yes. Compression happens locally in your browser and the file is never uploaded.
How much can a PDF be compressed?+
It depends on the content. Scanned and image-heavy PDFs often shrink by 70–90%, while text-only PDFs may shrink very little.
Why can't I select text after compressing?+
Compression re-renders each page as a JPEG image, so text becomes part of the picture. Keep the original if you need selectable text.
Can I compress a PDF to a specific size?+
Yes. Enter a target size in KB and the tool tries stronger settings until the file is at or below that size, when possible.
Which compression level should I choose?+
Medium suits most documents. Use low if images must stay sharp, and high when the smallest possible file matters most.
Is it safe to compress confidential documents?+
Yes. Compression runs locally in your browser, and the file is never uploaded to a server.
Is there a file size limit?+
No fixed limit. Very large PDFs just take longer and need more memory on your device.