How to Compress a PDF and Reduce File Size for Email
Reduce PDF file size for email and uploads. Learn the difference between lossless, smart image and strong compression, and which to choose.
"The attachment is too large." Few messages are more frustrating when a deadline is close. Many email services limit attachments to around 20 to 25 MB, and online portals for tenders, visas or job applications often accept even less. Compressing the PDF is the quickest fix, but not every method is equal. Some shrink the file and keep the text perfect; others make it tiny but turn every page into a picture.
This guide explains how to compress a PDF with Farino PDF, which mode to choose, and how to avoid common mistakes.
Why PDFs become so large
The usual culprits are images. A scanned page, a photo of a site visit or a high-resolution logo can each add several megabytes. Embedded fonts, duplicated resources and leftover data from editing also add weight. Compression targets these parts while trying to keep the document readable.
How to compress a PDF in Farino PDF
Compress PDF is available in the free edition.
- Open the PDF you want to make smaller.
- Click Convert › Compress PDF. The Compress PDF dialog opens with the active document.
- Under Method, choose a compression mode (explained below).
- For Smart image and Strong, set the Image quality. For Strong, also choose the Resolution.
- Click Compress and check the new size in the result.
The Compress PDF dialog with Lossless, Smart image and Strong modes
Which compression mode should you choose?
- Lossless optimises the file structure without touching image quality. Choose it for contracts and reports where everything must stay exactly as it is.
- Smart image recompresses the images inside the PDF while keeping text as text. It is the best balance for most documents with photos.
- Strong re-renders each page as a compressed image. It gives the biggest savings, but text can no longer be selected, searched or edited.
Image quality ranges from 30% to 95% (75% by default). For Strong mode you can choose 96 dpi · smallest, 120 dpi · balanced or 150 dpi · sharp.
The compression result showing the original and new file size
Tip: Keep the original file when you use Strong mode. Once pages become images, you cannot get the text layer back from the compressed copy.
A simple decision rule
Start with Smart image at 75%. If the file is still too big, lower the quality to 60%. Use Strong only for documents that people will read and print, not search or edit, such as a large scanned archive you need to upload once. If the compressed result says no recompressible images were found, the PDF is mostly text and already efficient.
Compress many files at once
If you regularly receive dozens of scanned PDFs, compressing them one by one wastes time. The Business edition includes Batch Processing and Watch Folder, which compress every new PDF automatically. Learn how in our guide to batch processing PDF files.
Other ways to reduce size
- Remove pages you do not need. Delete blank or duplicate pages before compressing.
- Split very large files. Send a big report in parts with Split PDF.
- Scan at the right resolution. 200 to 300 dpi is usually enough for documents.
Frequently asked questions
Does compressing a PDF reduce quality? Lossless mode does not. Smart image lowers image quality slightly, and Strong mode turns pages into images.
Is compression done online? No. Farino PDF compresses on your computer, so the document is not uploaded.
How small can a PDF get? It depends on the content. Image-heavy scans shrink the most; text-only PDFs are already small.
Conclusion
Compression is the easiest way to get past attachment limits, as long as you pick the right mode. Farino PDF gives you three clear options and shows the result instantly. Download Farino PDF for free and see the pricing page for batch tools in the Business edition.