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CSV Value Mapper
Replace exact values in one CSV column using a JSON codebook, with one lookup per original cell.
CSV, TSV, UTF-8 delimited text, JSON string-to-string mapping
CSV, TSV
Browser only
Runs locally in your browser. Your files, pasted content and generated output are not uploaded. Reset clears this tool’s working data.
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How to use this tool
- Paste or choose the CSV file and choose its delimiter.
- Enter the one-based Column position and provide a Mapping JSON object or mapping file. A selected file takes precedence over its corresponding text field.
- Choose Keep original or Reject unmapped values, and review Protect spreadsheet formulas.
- Select Apply value map and download mapped-values.csv or mapped-values.tsv.
Examples
For original column values A, B and Z, the mapping {"A":"B","B":"C"} produces B, C and Z when unmapped values are kept.
Limitations
- CSV needs a header and at least one data row, with unique nonempty header names and equal column counts. Quoted delimiters, line breaks and doubled quotes are supported.
- Up to 5 MiB UTF-8 input, 50,000 data rows, 500 columns, 500,000 cells and 20 MiB output.
- Choose comma, tab, semicolon or pipe explicitly. Output uses that delimiter; tab output downloads as TSV.
- Spreadsheet formula protection starts on. Formula expressions receive a leading apostrophe; complete signed numeric text stays numeric. CSV cannot declare cell types, so import leading-zero or signed IDs as text when needed.
- Mapping input is limited to 1 MiB and 10,000 entries. Every replacement must be a JSON string.
- Empty keys and prototype-like keys are ordinary exact data. No trimming, type coercion, regular expressions or cascading replacements are performed. Other cells and row order are preserved subject to the selected spreadsheet protection policy.
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