Compression is not a promise that every PDF will shrink. A source can already use efficient image encoding, compact object streams and subset fonts. Rewriting it may add metadata or replace an efficient representation with a less efficient one.

A larger result is not automatically broken; it simply failed the size-reduction goal. Keep the smaller original unless the output solves another structural problem.

Recognize already optimized files

PDFs exported by modern software may have little removable overhead. Vector-heavy pages and short text documents can be so small that processing headers outweigh any saving.

Avoid the common traps

Do not convert pages to images merely to call the result compressed. Rasterization can increase size, remove searchable text and reduce accessibility. Also avoid repeatedly compressing previous outputs.

  • Compare byte size, not only the rounded MB label.
  • Check whether fonts and images were duplicated.
  • Confirm that selectable text survived.

Choose the next action

If the original is smaller, keep it. For a photo-heavy source, return to the original images and resize them appropriately. For a structurally damaged file, use Repair PDF before evaluating size.