PDF guides

How to compress PDF without hurting readability

Learn how to choose a PDF compression level so the file is smaller while text, images, signatures, and tables stay readable.

Start with the purpose of the file

A PDF that will only be read on a phone or sent through chat does not need the same quality as a PDF that will be printed, signed, or archived. Before compressing, decide how the file will be used. If the document is only for quick review, a stronger compression level may be fine. If it contains small text, tables, certificates, stamps, or signatures, use a lighter level first.

BeresPDF shows compression levels as percentages so they are easier to understand. A higher percentage keeps more of the original size and quality. A lower percentage tries to reduce the file more aggressively. The final size is still an estimate because every PDF stores images, fonts, and page content differently.

Why compression results vary

Two PDFs with the same page count can behave very differently. A 20-page PDF made mostly of text may already be small, while a three-page scan can be huge because each page is stored as a large image. Compression works best when the PDF contains images that can be optimized.

If the result is only slightly smaller, it does not always mean the tool failed. The source file may already be compressed. If the result becomes blurry, the chosen level may be too aggressive for that document. In that case, try a higher percentage and compare the output.

Review visual quality before sending

After compression, open the result before sending it. Check small text, scanned signatures, QR codes, barcodes, tables, and images. Zoom in to 100% or more if the document will be read on a laptop or printed.

If the PDF is for an official form, invoice, certificate, or legal attachment, do not judge quality only from the thumbnail preview. Open the actual downloaded file and inspect the important parts. A file that is small but unreadable is usually worse than a slightly larger file that remains clear.

A practical way to choose the percentage

If you are unsure, start around 80% or 70%. These levels are often a reasonable balance for everyday documents. If the file is still too large, try 60% or 50%. Use lower levels such as 40%, 30%, 20%, or 10% mainly for image-heavy files where smaller size matters more than visual detail.

Keep the original PDF until you are satisfied with the compressed result. Avoid compressing the same file again and again because repeated compression can gradually reduce image quality. If you need a different result, go back to the original file and choose a different level.

Quick tips

• Start with 80% or 70% if readability matters.
• Use lower percentages for scanned or image-heavy PDFs when file size is the priority.
• Always open the compressed result before sending it.
• Keep the original file until you are sure the compressed version is acceptable.