Compress PDF Online
Choose a lighter or stronger optimization level to balance file size and image quality.
- Three compression levels Light, Medium and Extreme trade smaller files against image quality.
- Built for sharing Can shrink large PDFs so they are easier to attach to email or upload to forms.
- Free up to 10 MiB Larger files require a premium plan; compression itself does not consume credits.
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Max file size: 50 MB · Files deleted immediately after processing
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How to compress a PDF online
- Upload the PDF you want to shrink.
- Pick Light, Medium or Extreme depending on how much quality you can spare.
- Press Compress PDF and compare the before and after sizes.
Why compress a PDF
Attachment limits are the usual reason. Mail servers commonly reject anything past 10 or 25 MB, and upload forms for tenders, court filings and job applications are often stricter still. A smaller PDF also loads faster for whoever opens it on a phone, and costs less to store when you are keeping years of records.
About the size and quality trade-off
Nearly all the weight in a typical PDF is images, so that is where compression takes its savings. The three presets map to optimization levels 1, 5 and 9 in the processing engine; we do not publish a DPI figure per preset because the engine is not given a fixed one. In practice the stronger the level, the more aggressively images are recompressed and potentially downsampled, which shows first on photographs and scanned pages and last on text. Text-heavy documents therefore shrink less dramatically but stay crisp. There is no guaranteed output size, so if you are aiming at a hard limit, start with Medium and step up only if you must.
Frequently asked questions
- How can I compress a PDF without losing too much quality?
- To compress a PDF without sacrificing more image quality than necessary, start with Light or Medium. The presets send optimization levels 1, 5, and 9 to the engine, but there is no fixed DPI for each level; stronger compression can make image-heavy pages look softer.
- Will compression reach a specific target file size?
- Not necessarily. Savings depend on how the PDF was created and whether its images, fonts, and other objects are already optimized. Some files may shrink only slightly, and the result is not guaranteed to fit a particular email or upload limit.
- Is PDF compression free, and does it use credits?
- Files up to 10 MiB can be compressed without using a credit. Larger files require a premium plan, but compression itself does not consume credits.
- Does compression happen in my browser?
- No. Your PDF is uploaded to the processing service for compression and the result is returned for download. Avoid uploading material you are not permitted to process through a server.