kohaku-lab pdf-merge
Use this skill for any operation on PDF files: merging, splitting, reordering pages, or extracting a subset.
Decision tree
| Task | Tool |
|---|---|
| Combine 2+ PDFs into one | qpdf or pdftk |
| Extract page ranges | qpdf --pages |
| Reorder pages | qpdf --pages |
| Convert PDF to images / text | Not this skill — |
| use a dedicated | |
| tool (pdftotext, | |
| pdfimages). |
Merging (preferred: qpdf)
qpdf --empty --pages in1.pdf in2.pdf in3.pdf -- merged.pdf
Fallback when qpdf is not installed:
pdftk in1.pdf in2.pdf in3.pdf cat output merged.pdf
Verification (required)
Always count pages in the output and sanity-check against the sum of the inputs:
qpdf --show-npages merged.pdf
Report the page count back to the user. If the numbers don't add up, flag it — a malformed input PDF silently drops pages in some concatenation tools.
Safety
- Never overwrite the original inputs. Write to a new filename.
- If the output file already exists, ask before overwriting.
- Do not
--linearizeunless the user asks for it (changes file size noticeably).