How to Use This Tool
Turn wide repeated-measure columns into tidy variable and value rows. Convert wide CSV tables to long form by choosing identifier and value columns, validate headers, preview row expansion, and download tidy CSV.
The work this page finishes
Repeated month, region or measurement columns are convenient for reading but awkward for grouping and charting; manual unpivoting multiplies rows and copy errors. For Wide to Long CSV, keeping source order beside the computed artifact lets a user repair only the failed entries and reproduce the same batch later.
Deterministic workflow
Resolve explicit identifier and value headers, then emit one output row per source-row/value-column pair while retaining identifiers and the original value-column label. For Wide to Long CSV, a run is capped at 5,000 items and 2 MB, preventing an accidental oversized paste while preserving successful rows when another row fails.
Why a dedicated interface helps
Review the expanded preview and data types before analysis; this structural reshape changes row granularity but does not aggregate or clean values. For Wide to Long CSV, a purpose-built form exposes every assumption and returns the same ordered structure on every run, which is more practical than reconciling shifting conversational output.
Assumptions
- Headers are unique after trimming.
- Selected value columns represent the same kind of measure.
- Identifier plus variable fields identify the intended observations.
For Wide to Long CSV, keep an untouched copy for comparison after import; the browser performs the work locally, but local software and extensions are not controlled by this page.
Limitations and review boundary
It does not infer identifier columns, normalize dates, merge duplicate observations, evaluate formulas or process files beyond the local row and size limits. For Wide to Long CSV, the implementation neither follows user-entered links nor evaluates their contents, and it displays material as plain text rather than active HTML.
Verification and provenance
Fixtures derived from the displayed rule and Wickham — Tidy Data were reviewed on 2026-08-26; they include normal, empty or invalid, and partial-failure behavior. Two source rows and three selected month columns deterministically become six long rows with store and product retained.
Sources & assumptions
Tool Spec v2 · verified 2026-08-26. Platform rules and fees can change; the editable inputs remain authoritative for your account.
Official references
- Wickham — Tidy Data (checked 2026-08-26)
Model assumptions
- Headers are unique after trimming.
- Selected value columns represent the same kind of measure.
- Identifier plus variable fields identify the intended observations.
- It does not infer identifier columns, normalize dates, merge duplicate observations, evaluate formulas or process files beyond the local row and size limits.
