PDF Compressor & Optimizer
Make a PDF smaller so it is easier to email, share, or store. Upload the file, optionally reduce the embedded image size, and download the result — no signup, no upload to any server.
Short answer
Compression works best on PDFs that contain large scanned images. Many text-based PDFs are already small, so the result may not shrink much. When you turn on image reduction, each page is rendered at a smaller size, which can lower quality.
What PDF compression actually does
PDF compression is not one single thing. Some PDFs shrink because they contain duplicated or inefficient content that a re-save can trim. Others are large because they hold big scanned images or embedded photos, and those are the ones that respond best to image reduction.
The honest result is that some PDFs get much smaller and some barely change. Text-heavy files are often already efficient, so the tool may not reduce them much. That is normal, not a failure.
| File type | Likely result | Why |
|---|---|---|
| Scanned image PDF | Often shrinks a lot | Large embedded images |
| Photo-heavy PDF | Can shrink a lot | Reducing image size removes raw data |
| Text-only PDF | Usually little change | Already efficient to begin with |
| PDF with forms or fonts | Varies | Depends on how it was created |
How to compress a PDF without losing what matters
- Start by looking at why the file is large. A scanned PDF and a text PDF usually need different fixes.
- If the PDF is already small, do not force compression just because you can.
- If you need the file smaller for email or upload, reduce image size first, since that is where the bytes usually are.
- Check the compressed version before you rely on it, especially if the pages contain fine print or photos.
How to reduce a PDF file size
Upload the PDF
Open the PDF Compressor and upload the file you want to make smaller. The file stays on your device.
Choose image reduction
If the PDF has large scans or photos, turn on image reduction. If the file is already small, leave it off and just re-save.
Set size and quality
Pick a max image size and a quality level. Smaller values reduce file size more but can soften the page image.
Compress and download
Compress the file, compare the before and after size, and download the smaller version if it is worth keeping.
When compression helps most
Large scanned documents and photo-heavy PDFs are the best candidates. If you only need the file smaller for sharing, reducing the image quality a little can make a big difference. If you need the pages sharp, keep the reduction light or skip it.
FAQ
How do I reduce the size of a PDF?
Upload the PDF and choose whether to reduce the embedded image size. The tool shows the before and after size, then lets you download the smaller file. It runs in your browser.
Why is my PDF still large after compression?
Some PDFs are already small, especially text-only documents. Compression helps most when the file contains large scanned images or embedded photos.
Does compressing a PDF reduce quality?
It can. If the file has large images and you choose to reduce their size, the pages may look slightly softer. Text-only PDFs usually lose very little.
What is the best way to compress a scanned PDF?
Scanned PDFs are usually the ones that shrink the most. Reducing the embedded image size is the main lever, and it is most effective when the scan is much larger than you need.
Is PDF compression free?
Yes. It is a free browser tool with no signup. Your PDF is processed on your device and nothing is uploaded to a server.
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