Start with repair when the file behaves inconsistently
If a PDF opens in one application but fails in another, or conversion fails even though the pages look present, the internal structure may be messy. Rewriting the file and cleaning redundant objects can create a more consistent container before the next operation.
Repair cannot recreate missing content
If a page is already missing or a stream is damaged beyond what the PDF engine can read, structural repair cannot invent that data. Keep the original and treat the repaired output as a new copy that must be compared.
Test more than appearance after repair
Open the first, middle, and last pages, then test search, text selection, and any important links. A file opening successfully does not prove that every advanced document feature survived a structural rewrite.
When compression should come next
Once the repaired copy looks and behaves correctly, compression can be a useful sharing step. Repairing first and compressing the clean result is safer than trying to optimize a PDF that is already behaving unpredictably.
Compare the original and repaired copies with concrete checks
Do not rely on a general visual impression after repair. Compare page count, file size, search behavior, links, images, and any important annotations or form fields between the source and the new copy. For academic, legal, or operational documents, inspect pages from the beginning, middle, and end and record any meaningful difference before treating the repaired file as the new working version.
Do not make repair an automatic step for every PDF
A healthy PDF does not need to be rewritten before every conversion. Each extra processing step creates another output that should be verified, and unnecessary rewriting can remove or normalize features you actually wanted to keep. Use repair when there is evidence of structural trouble, then proceed to compression or conversion only after the repaired copy passes the checks that matter for your task.