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Contain preserves the complete page
Contain uses the smaller proportional scale so the entire source fits inside the available target area. Any remaining space becomes margin or background.
It is the safest default for certificates, contracts, scans and pages where no edge may be lost. Small text can become harder to read when a large page is reduced substantially.
Cover fills the sheet and can crop edges
Cover uses the larger proportional scale, filling both target dimensions. Content that extends beyond the available area is clipped by the new page boundary.
Use it for full-bleed artwork or image-led pages only after checking titles, page numbers and other edge content. Alignment determines which side receives the crop.
Actual size and stretch solve different needs
Actual size keeps the original physical scale where possible. A source larger than the target can extend beyond it, so placement and page selection matter.
Stretch fills the exact width and height independently. It removes empty space but changes proportions, which can distort circles, logos, photographs and typography.
| Mode | Preserves proportions | Shows every edge |
|---|---|---|
| Contain | Yes | Yes |
| Cover | Yes | Not always |
| Actual size | Yes | Depends on target |
| Stretch | No | Yes |
Alignment controls where remaining space goes
Centering distributes spare space evenly. Top, bottom, left and right alignment can protect an important edge or create a predictable binding margin.
Preview portrait and landscape exceptions. A single alignment choice can behave differently when source and target proportions change between pages.
Put the workflow into practice
Add a PDF, inspect its detected dimensions, choose the target geometry and placement rules, then reopen the verified result before printing or distribution.
Try Change PDF Page SizeFrequently asked questions
Clear answers before you merge
Which mode is safest?
Contain is the safest default because it keeps every source edge visible.
Does cover distort content?
No, it preserves proportions but may clip edges.
When should I use stretch?
Only when filling exact dimensions matters more than preserving proportions.
Can I prevent enlargement?
Yes. Disable enlargement to keep smaller pages at or below their original scale.
