PDF compression guides
How to Choose a PDF Compression Mode
Start from the document's content and delivery goal, then verify the result instead of choosing by label alone.
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Choose a PDF compression mode by asking what makes the document large and what quality the recipient needs. Use a moderate or Smart approach for mixed documents, an image-aware approach for photo-heavy scans, and a lighter setting for print or fine-detail work. Download the result, compare it with the original, and switch modes only when the evidence shows a problem.
Match the mode to content and destination
Compression labels summarize trade-offs; they do not know whether a particular screenshot, form, or print detail is essential. Adobe's optimizer guidance illustrates the range of settings that can affect PDF size and quality. PDFStay's tool supports a practical browser workflow, but your output still needs a direct check.1, 2
| Content | Starting mode | Quality priority |
|---|---|---|
| Text plus ordinary images | Smart or moderate | Readable text and balanced size |
| Print, fine diagrams, or key photos | Light or conservative | Detail before maximum reduction |
Let the output decide whether to change mode
- Define the destination limit and quality requirement.
- Compress a copy with the least aggressive useful mode.
- Inspect high-risk pages and required features.
- Try another mode only when the first output misses the target.
FAQ
Which mode is best for a scanned PDF?
Start with an image-aware or moderate approach and inspect small characters, signatures, and stamps. A scan that carries evidence may need a lighter setting.
Should I always choose the strongest compression?
No. Stronger reduction can trade away visual detail or features. Use the least aggressive mode that meets the actual size requirement.
Sources
- PDFStay — Compress PDF workflowPDFStay first-party methodologySource reviewed:
- Adobe Acrobat — PDF Optimizer settingsofficial technical documentationSource reviewed: