No implicit coercion
Leading zeros, long identifiers, date-like strings and formula-like text remain visible as written.
A CSV editor that shows its work
View the complete table, edit cells and rows, filter and sort, calculate columns, join lookups and build transformations without letting identifiers turn into numbers or dates.
Private early access · macOS & Windows
DataTransformCompareIssues 6RecipeRun report
customer_iditemquantityunit_priceline_total
1001234Shipping box124.5054.00
2001235Label roll812.0096.00
3001236Paper tape243.2076.80
4001237Packing slip49.2537.00
5001238Return label67.5045.00
Text values remain textUTF-8 · comma · CRLF2 unsaved edits
Text stays text until you decide otherwise
CSVProof opens values as CSV fields, not spreadsheet guesses. Casts and normalizations are explicit transformations with a before-and-after preview.
Visible parsing
Encoding, delimiter, quoting, header and newline choices form a saved contract.
Safer output
Consequential normalization is counted and previewed. Output is verified after an atomic write to a new file by default.
Edit in the context of the whole run
The grid is the main workspace. Comparison, transformations and issues stay connected to the rows they affect.
JobWhat CSVProof makes explicitResult
ViewRaw values beside the parsed table; search, sort and filter without changing the file.Understand first
EditCell, row and bounded bulk changes with dependable undo and no automatic value conversion.Controlled change
ProfileNulls, distinct values, ranges and suspicious distributions before rules are applied.Know the file
CalculateAdd derived columns with named expressions such as quantity × unit_price, then preview every result.Visible calculation
TransformRename, trim, replace, map, filter, deduplicate, join and normalize as visible steps.Reviewable recipe
CompareOne or more record keys, duplicate/null key checks and per-field differences.Real record identity
ReleaseException decisions, row counts, contract versions and input/output hashes.Evidence report
Transform the table without losing sight of the rows
Every cleanup or calculation becomes a named step beside a live preview. Add a derived column, map values, join another CSV, filter records or normalize text, then inspect the result before applying it.
Calculations do not change the source field type behind your back. They create explicit output columns that can be reviewed and replayed.
DataTransformCompareIssues 6RecipeRun report
Trim whitespacename, item228 cells
Calculate line_total
quantity * unit_price12,481 cellsMap country codescountry_lookup.csv4 misses
Keep active recordsstatus = active93 removed
customer_idquantityunit_priceline_total
001234124.5054.00
001235812.0096.00
001236243.2076.80
00123749.2537.00
One workflow, three durable artifacts
The table is where you work. The contract, recipe and run report make that work repeatable and explainable.
Contract
How the file is parsed, which columns and keys are expected, and what should stop the run.
Recipe
The ordered calculations, lookups, transformations and output settings you approved.
Run report
What came in, what changed, which exceptions were decided and what was written.
The next file should not restart the process
Save an approved workflow as a human-readable recipe. When the next export arrives, CSVProof checks the parser and data contract, surfaces drift, and reruns only after the differences are understood.
- Explicit parser and output dialect
- Required fields, allowed values and unique keys
- Deterministic calculations, transforms and lookups
- Assertions that stop unsafe output
- Versioned run report
DataTransformCompareIssues 6RecipeRun report
Require unique customer_idcontractRequired
Trim name and addresstransform228 cells
Calculate line_totalquantity * unit_priceFormula
Join account lookupone to one match4 misses
Write UTF-8, comma, CRLFoutput formatOutput
Expected result
Rows read12,481
Rows ready12,475
Issues6
Changed cells228
Your CSV files stay on your computer
CSVProof is paid desktop software for macOS and Windows. Source files are processed locally; no account or source-data cloud is required for the core workflow.
A focused data workbench, not a general spreadsheet.
Calculations are explicit transformation steps. CSVProof leaves out charts, cell styling, cloud sync and AI guessing so the data workflow stays inspectable.
Bring repeatability to the CSV work you already do
CSVProof is currently in private early access for macOS and Windows.
Get early access