Compress PDF Online Free

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

How to Compress PDF

  1. 1Drop your PDF into the box or click to choose it.
  2. 2Pick a compression level: low, medium or high.
  3. 3Optionally enter a target size in KB, such as 500.
  4. 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.

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Frequently asked questions

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.