Compress PDF Online: Reduce a PDF's File Size
A large PDF can be difficult to email, upload to a form, or share with colleagues. Compressing a PDF may reduce its size, especially when pages contain high-resolution images. The amount of reduction depends on how the original file was created.
How to make a PDF smaller
- Keep a copy of the original PDF.
- Open PDFLeo's compression tool and choose your file.
- Select the available quality setting and run the tool.
- Download the output and compare its size with the original.
- Zoom in to check small text, diagrams, signatures, and images before using or sending the file.
Why can compression affect quality?
Some compression methods reduce size by rendering pages as images. This can make the text less sharp and may remove selectable/searchable text, links, form fields, or other interactive features. Always inspect the output and do not assume every kind of PDF can be compressed without trade-offs.
Other ways to reduce PDF size
- Resize very large images before adding them to a document.
- Export the original document using a reasonable image-quality setting, if available.
- Remove unnecessary pages from a copy of the document before sharing.
- Avoid repeatedly compressing the same file, since quality can degrade.
Frequently asked questions
Will compression always make a PDF smaller?
No. Already-optimized or mostly text-based PDFs may not shrink much, and some files may become larger depending on the processing method.
Will my PDF remain searchable?
It depends on the compression method. Image-based processing may turn text into page images, so test search and copy/paste on the downloaded result.
Should I compress signed or official documents?
Keep the original. Processing can affect digital signatures, forms, links, or document quality. Check requirements before modifying an official file.
Related guides: Merge PDF · Split PDF · All PDF tool guides