Reduce PDF size and check image quality
PDFs become large for different reasons. Image resolution and encoding can offer room for compression, but a single reduction percentage does not apply to every document. Start with the recipient’s size limit and the quality you need.
Use the toolKnow when compression can help
High-resolution photos and scanned pages can account for most of a PDF’s size. For screen reading or email, compare the available results and choose an acceptable balance of image quality and size.
Short text documents, already-compressed images and optimized PDFs may have little room to shrink. Keep the original if no smaller useful result is available. Removing unwanted pages or splitting out only required pages can be another way to meet a size limit.
How to use
Check the size limit and purpose
Find the recipient’s upload or email limit and decide whether the file is for print or screen reading.
Run PDF compression
Select the PDF and start compression. Compare the available results with the original size. A file that does not shrink can be kept in its original form.
Open the result before using it
Check page count, small lettering, photos and tables. If several results are available, choose one that meets the size limit while preserving the quality you need.
Inspect the important details
Check small text, faint stamps, thin table borders and photo edges at the size people will read them. For printing, inspect the document at its intended print size.
An entire scanned page may be a single image, so compression can affect the text too. Keep the original of plans, evidence and other detail-sensitive documents. Judge whether the result can still be read and used, rather than choosing by the reduction percentage alone.
Keep the original and result separate
Compare the original and result sizes before downloading. Saving the compressed copy separately lets you return to the original if quality is unsuitable.
The public tool processes files in the browser. Large images can use considerable device memory. If a batch causes trouble, process one file at a time and check the displayed limits and error messages.
Troubleshooting
The file is not smaller
It may be text-heavy or already optimized. Instead of repeatedly compressing it, consider splitting out needed pages or removing unnecessary ones.
Text or stamps look blurry
Image quality may have been reduced. Compare with the original and use a clearer result or the original. Information lost through lossy compression cannot be recovered from the compressed copy.
A large file stopped processing
Check the size limits and available browser memory, then try one file at a time. Keep the original before reopening a tab; an unfinished result may not have been saved.