LibreOffice 26.8.0.3: default headless round trip
A UTF-8/LF CSV was converted to XLSX and back to CSV on macOS 15.5. The round trip completed in 6.8 seconds, but several logical values changed.
| Case | Input | Output observation | Classification |
|---|---|---|---|
| Leading-zero ID | 00001234 | 1234 | Silently changed |
| 30-digit identifier | 123456789012345678901234567890 | Scientific notation | Silently changed |
| 20-digit zero-padded value | 00000000000000000042 | 42 | Silently changed |
| Formula-like text | =2+2 | 4 | Evaluated / changed |
| Quoting & whitespace | Mixed fixture | Output representation changed | Normalized |
Test the whole round trip, not the opening screenshot
Record product version, OS, hardware, input hash and exact import settings.
Note what the user sees before editing and whether parser choices or warnings are visible.
Run zero-edit save, one-cell edit, filter/export, compare and recovery where supported.
Measure both byte differences and decoded logical-value differences, including rejected or skipped rows.
Report preserved, warned, normalized visibly, silently changed or rejected per case. No fake overall winner.
Small files with consequential edges
The seed fixture combines cases that are individually ordinary and collectively useful for regression testing:
Planned products, without invented outcomes
Products enter the public result table only after the same operation is completed and documented. CSVProof will be tested by the same rules when an executable build exists.