Which compare tool should I use?
ListDiff has several modes on purpose. Pick the row that matches your question—opening the wrong one is why results feel “wrong” even when the math is fine.
Match your question
What’s missing or extra between two lists?
→ Compare lists
A only / B only / Intersection. Order usually does not matter.
Combine two lists into one unique list?
→ Merge lists
A then new items from B—no spreadsheet formulas.
Three sources (channels, classes, exports)?
→ Compare three lists
Only A/B/C, pairwise overlaps, and all-three.
Which values repeat inside one list?
→ Find duplicates
Counts and line numbers, then copy a unique list.
Wording or line order changed in a file?
→ Compare text
Line-by-line red/green diff for drafts and configs.
Two JSON payloads (API / fixtures)?
→ Compare JSON
Path diffs; object key order ignored.
Same SKU/ID but price or stock changed?
→ Compare CSV
Match rows by key, then see changed cells.
Only care which CSV IDs appeared or disappeared?
→ CSV as ID lists
Extract Col N, then use list compare buckets.
Quick rules
- Membership (exist or not) → lists, merge, three lists, or duplicates.
- Ordered edits → text. Structured objects → JSON. Tables with a key → CSV.
- Still stuck after a list compare → read why two lists don’t match.
FAQ
Which ListDiff tool should I use?
Start from the table above. Most “IDs / emails / SKUs” jobs are list compare or merge; API payloads are JSON; catalogs with price edits are CSV.
Is CSV table compare the same as extracting a CSV column?
No. Column extract + list compare = which keys. Table compare = which cells on the same key.