Reduce PDF File Size
An email bounces because the attachment is too big, or an application portal only accepts files up to 2 MB. In most large PDFs, the size comes from photos and scanned pages – and that is exactly where the file can be made smaller.
Choose your PDF and a compression level. Images are optimized in your browser, while text and layout stay as they are.
Your files stay on your device. Conversions run in your browser.
Works best with PDFs that contain photos or scanned pages. PDFs with only text are often already small.
Your files stay on your device. Conversions run in your browser.
- No signup required
- Files stay on your device
- Browser-based conversion
- Fast download
- Free to use
Why some PDFs are so large
Text needs very little space in a PDF. Photos, scans and screenshots are what make files heavy, especially when they were added at full camera resolution. Reducing the size means re-encoding these images more efficiently, which keeps them clear on screen but takes much less space.
How much smaller will my PDF get?
- Scanned documents and PDFs with many photos usually shrink a lot.
- PDFs that are mostly text are often already small and change little.
- If a PDF is already well optimized, the tool tells you instead of producing a larger file.
- A stronger level saves more space; check the result if images contain small print.
Other ways to get under a size limit
If the file is still too big, split it into smaller parts or remove pages you don't need with the PDF editor, then send the parts separately.
Privacy: your files stay on your device
Your files stay on your device. Conversions run in your browser. PDFConvertFast never uploads, stores or reads your documents – there is no server that receives them, no account and no email address.
- Your files stay on your device
- No signup required
- Browser-based conversion
Reduce PDF size – questions and answers
How do I reduce the size of a PDF?
Choose your PDF, keep “Recommended” or pick “Strong” for an even smaller file, and click “Compress PDF”. The images in the PDF are re-encoded more efficiently while text and layout stay as they are. Then download the smaller file.
Why is my PDF file so large?
Almost always because of images. Scanned pages, photos and screenshots added at full resolution take far more space than text: in our tests a 6-page scan at 300 dpi was 19.3 MB, while a text-only PDF was 35 KB.
How do I make a PDF small enough to email?
Compress it with “Recommended” first and check the new size – many email services accept attachments only up to about 20–25 MB. If it is still too big, try “Strong”, split the PDF or delete pages you don’t need.
What is the difference between “Recommended” and “Strong”?
“Recommended” scales images to at most 2,000 pixels on the long side and keeps good quality, which suits most documents. “Strong” goes down to 1,400 pixels with stronger compression for the smallest file. Small print in scanned pages can become softer with “Strong”, so check the result.
Will compressing a PDF reduce its quality?
Text and vector graphics are not changed; they stay sharp and selectable. Only images are re-encoded, so photos and scanned pages lose some detail – hardly visible with “Recommended”, more noticeable with “Strong”.
Why did my PDF hardly get smaller?
PDFs that consist mainly of text or are already optimized have little left to save. In that case the tool tells you instead of giving you a file that is not smaller. The biggest savings come from scans and photos.
Can I compress a PDF to an exact size like 100 KB?
Not to an exact size – the tool optimizes the images as far as the chosen level goes. For strict upload limits, see Compress PDF to 100 KB with measured results and tips.
Is there a file size limit, and is it free?
Each PDF can be up to 200 MB. Compressing is free, with no signup and no watermark.
Can I reduce PDF size on iPhone or Mac?
Yes. The tool runs in a current browser such as Safari or Chrome, so it works on iPhone, Android, Mac and Windows without installing anything.
Is my PDF uploaded when I compress it?
No. The PDF is compressed in your browser on your own device; it is never uploaded to a server or stored.