How to compress a PDF
- Drop one PDF into the box above or press Browse files.
- Pick a target resolution. Use 120 DPI for screens and 150 for print.
- Set the image quality. 70 suits most scanned text.
- Press Compress and read the before and after size.
- Download the smaller file. Keep your original too.
What this PDF compressor gives you
- A resolution you control instead of a hidden guess.
- Cuts of 80 to 95 percent on most scanned documents.
- The same page size so print layout stays the same.
- The before and after size in bytes and as a percent.
- A plain warning when the result comes out bigger.
- No upload which matters for contracts and records.
Why are PDF files so big?
Images almost always decide the size of a PDF. A page of text takes a few kilobytes. Letters and font references use almost no space.
A scanned page is a photo though. A scanner set to 600 DPI in color can make close to 20 MB for one sheet. Twenty pages like that make a file nobody can email.
Photos inside a report work the same way. Thirty product shots at full camera size stay at full weight. Each one fills only a few centimeters on the page. The printed size has nothing to do with the pixels stored behind it.
How this PDF compressor works
The tool renders each page at your chosen resolution. Then it rebuilds the document from those renders as JPG images. It keeps the original page size.
That is a blunt method on purpose. A browser cannot rewrite every part of a PDF. So this is the most reliable approach it can take.
Be clear about the result. The output is a picture of each page.
- Selectable text becomes an image of text.
- Links stop working.
- Form fields become pictures of fields.
- Search finds nothing.
In return a 40 MB scan can drop to 2 MB. It finally fits the upload box.
When to use a PDF compressor
| Document | Result | Advice |
|---|---|---|
| Scanned contracts, receipts and forms | Excellent | They had no text layer anyway |
| Image heavy brochures and reports | Good | Photos drive the size |
| Text files from a word processor | Poor | Already small and loses search |
| Forms you need to fill in | Avoid | Fields stop working |
Is a text based PDF bigger than it should be? The cause is usually a few huge images or fonts. Shrink those images before you build the PDF. The image compressor fixes that with no loss of text.
Pick the right resolution and quality
Resolution is the bigger lever. Half the resolution removes three quarters of the pixels.
- 96 to 120 DPI: easy reading on screen.
- 150 DPI: survives an office laser printer.
- 200 and above: rarely worth it here.
Quality then controls the JPG compression on top. 70 suits scanned text. Go lower and the letters pick up a visible haze. Text looks soft? Raise the resolution before you raise the quality. Soft text is usually a resolution problem.
What if the PDF gets bigger?
This can happen. The tool tells you rather than hiding it. A PDF that was already well compressed has little to give. A text document or a scan someone already shrank may grow. Images take more space than letters. Keep the original in that case.
Lossless ways to shrink a PDF
Sometimes you do not need every page. Remove the extras with the PDF page deleter. Or keep just the section you send with the PDF page extractor. Both are lossless and often enough on their own.
A quick PDF compressor example
Say you scanned a 12 page lease at 600 DPI in color. The file weighs 60 MB. Your landlord's portal caps uploads at 10 MB.
- Set the resolution to 120 DPI.
- Set the quality to 70.
- Press Compress.
The result often lands near 3 MB. The text stays easy to read on screen. You upload it and move on.
Common PDF compressor problems
The text looks blurry
Raise the resolution to 150. Keep the quality near 70.
The file is still too big
Delete pages you do not need. Then compress again at 96 DPI.
The form fields stopped working
Compression flattens every page. Fill in the form first and then compress the finished copy.
Who uses a PDF compressor?
Job seekers fit scanned certificates under portal limits. Renters send ID scans to landlords. Students upload scanned homework. Small business owners email signed contracts. Each one hits a size cap and needs a smaller file fast.
Your documents stay on your device
The tool never uploads your PDF. Your browser does every step. That matters because people mostly compress contracts, records and statements.