Email Attachment Limits
Most email services impose attachment size limits — Gmail caps at 25 MB, Outlook at 20 MB. If your PDF exceeds these limits, you'll either need to use a cloud sharing link or compress the file. Our PDF compressor can significantly reduce file sizes, often by 40–70%, making it easy to attach documents directly to emails without any hassle.
Online Form Uploads
Many government portals, university applications, and job boards have strict upload limits for PDF documents — sometimes as low as 2 MB or 5 MB. Scanned documents and image-heavy PDFs often exceed these limits. Compressing your PDF ensures you can complete your submission without running into "file too large" errors.
How PDF Compression Works
PDF compression works by optimizing the internal structure of the document. This includes removing duplicate objects, compressing embedded images, eliminating unused metadata, and applying stream compression. Our tool uses the PDF-lib library to process the file directly in your browser. The "Low" setting applies minimal compression for near-original quality, while "High" applies aggressive optimization for the smallest possible file size.
Tips for Maximum Compression
- Scanned documents benefit the most from compression — they often contain large embedded images that can be significantly reduced.
- Text-heavy PDFs are already compact — compression may only reduce their size by 10–20%.
- Start with "Medium" — it offers the best balance of size reduction and quality for most use cases.