The Best PDF Compression Settings for Every Use Case
Compression is not one setting — it is a range of trade-offs. The right level depends entirely on what you plan to do with the file. Below are the recommended settings for common scenarios.
Email attachments
Recommended: Balanced (Compress PDF), or target 5–15 MB.
Email providers typically cap attachments at 20–25 MB. A Balanced compression usually drops a 20 MB PDF to 5–8 MB without visible quality loss. Good for:
- Sending reports to colleagues.
- Sharing scanned documents.
- Sending invoices and contracts.
Portal uploads with tight limits
Recommended: Target-size tool (100KB, 200KB, 500KB) or Custom Target-Size.
Job portals, university applications, government forms — these often have hard limits like 2MB or 500KB. Use the specific target-size tool so you don't overshoot. If the target is unreachable, the tool returns the smallest file and shows you the actual size so you can decide whether it is acceptable.
Web publishing
Recommended: Strong (Compress PDF), or convert to images.
If you are embedding a PDF in a website, size matters for load time. Strong compression brings most documents under 2MB. Alternatively, convert pages to WebP images with PDF to WebP and display them as images — modern web design often works better with images than with embedded PDFs.
Archiving and long-term storage
Recommended: Light compression, or Optimize PDF without rasterization.
Archival copies should preserve quality and readability for future reference. Use Light compression or the Optimize PDF tool to remove metadata and recompress streams without rasterizing pages. The savings are modest but the quality is preserved.
Professional printing
Recommended: No compression, or Optimize PDF only.
Print work needs high resolution images (300 DPI) and embedded fonts. Compression that rasterizes pages destroys the print quality. If the file is too large for a print shop's upload limit, use a file transfer service instead of compressing — or ask the shop if they have a direct upload option.
Mobile viewing
Recommended: Strong compression.
If the PDF will be read on a phone screen, 100 DPI effective resolution is enough for comfortable reading. Strong compression brings most documents to 1–3 MB without losing readable text on a phone.
Signing and stamping workflows
Recommended: Light compression or none.
Signed PDFs need their integrity preserved. Compression that changes the bytes invalidates digital signatures. Compress before signing, not after.
Sharing scans of handwritten notes
Recommended: Balanced or Strong, with grayscale conversion.
Handwritten notes compress well because they are mostly white space. Convert to grayscale with Grayscale PDF first, then apply Balanced compression. The result is often 10–20% of the original size.
Summary table
| Use case | Tool | Level |
|---|---|---|
| Compress PDF | Balanced | |
| Portal upload (tight limit) | Compress to 100KB/200KB/500KB | Target-size iteration |
| Web publishing | Compress PDF | Strong |
| Archiving | Optimize PDF | No rasterization |
| Professional printing | None | Do not compress |
| Mobile viewing | Compress PDF | Strong |
| Signing | Compress before signing | Light |
| Handwritten scans | Grayscale + Compress | Balanced or Strong |
The safe default
If you are unsure, use Balanced. It gives reasonable size reduction with visual quality that is indistinguishable from the original for most documents. You can always compress further if the result is too large, but you cannot recover quality if you compress too aggressively.
Always keep the original
Compression is one-way. Once you save the compressed file, the original quality is gone. Keep the original file in a folder or cloud location and use the compressed version only for the specific destination.