Shrink PDFs for Email
Most email providers limit attachment sizes to 10-25 MB. If your PDF is too large, UnblockPDF's compression tool can reduce it significantly while maintaining readable quality.
Choosing the Right Compression Level
Low compression reduces file size by 10-30% with almost no visible quality change. Ideal for documents with important graphics or photos whose sharpness must be preserved.
Medium compression offers a good balance between size and quality, typically reducing files by 40-60%. The best choice for most business documents, reports, and presentations.
High compression achieves maximum reduction (60-90%) and is recommended when only the text content matters and embedded images can tolerate a lower resolution.
Why PDFs Get So Large
The most common causes of oversized PDFs are high-resolution images, embedded fonts that appear multiple times, and metadata or hidden layers from design software. Scanned documents are especially prone to large file sizes because each page is stored as a full raster image. A single-page scan can easily reach 3-5 MB, meaning a 20-page document can quickly balloon to 60-100 MB.
Tips for Smaller PDFs
Before compressing, consider removing unnecessary pages with our Split tool. If you only need to email specific pages of a long report, extract those first and then compress just the relevant portion. This saves additional file size and makes it easier for the recipient to find the content they need.
Practical Scenarios
Job applications: Certificates and work samples often become too large as scans. Compress each document individually at medium level before combining everything.
Client presentations: Marketing PDFs with many images regularly exceed attachment limits. Medium compression reduces the size without making graphics look pixelated.
Government submissions: Many online portals for government agencies have upload limits of 5-10 MB per file. High compression helps the most in these cases.
Check After Compressing
Open the compressed file and verify that texts remain legible and images are sufficiently sharp. If the quality does not meet your needs, repeat the compression at a lower level. All processing happens entirely in your browser, so you can make as many attempts as you like without any waiting time or server uploads.