Focused purpose
What this tool does
Find blank, null, N/A, NA and dash markers in CSV or TSV locally. Keep, fill, remove or quarantine affected rows and download checked outputs without an account.
- ✓ Blank and marker detection
- ✓ Per-column treatment
- ✓ Row quarantine
- ✓ Separate problem-row export
Workflow
How to use it
- 01
Open the file and select the columns to inspect.
- 02
Choose markers and an explicit treatment.
- 03
Preview row counts and export main and quarantine files.
Available controls
Available options
- Distinguish empty text from null markers.
- Keep, fill, remove or quarantine.
- Apply choices only to selected columns.
- Download affected rows separately.
Mixed missing markers
Example before and after
Three different markers represent missing values.
Before
id,city,phone 1,Paris, 2,NULL,0102 3,Lyon,N/A
After
id,city,phone 1,Paris,unknown 2,unknown,0102 3,Lyon,unknown
Expected result: Chosen markers are replaced consistently while other text is preserved.
Practical scenarios
Common use cases
Prepare required fields for import.
Separate incomplete survey responses.
Standardize vendor null markers.
HONEST LIMITS
Important limitations
- iA dash may be meaningful data and is never assumed missing automatically.
- iMean, median and mode create inferred data and run only after that strategy is explicitly selected.
FAQ
Questions about this tool
Is NULL different from an empty cell?
Yes. They are separate raw values until you explicitly classify NULL as a missing marker.
Can I remove only rows missing a required email?
Yes. Target the email column and choose row removal after previewing the count.
Can I download incomplete rows separately?
Yes. Quarantine creates a separate checked CSV while preserving the main copy.