Standardize messy date formats in a CSV.
Mixing 03/14/2024 with 14 Mar 2024 and 2024-03-14 in the same column? CSVTidy detects the date column, parses each row, and rewrites the whole column in the format you pick — ISO, US, or EU.
Everything runs in your browser. Nothing is uploaded.
Drop a CSV or Excel file here
Or choose a file — nothing leaves your browser.
Common questions
Which date formats can it parse?
ISO (2024-03-14), slash formats (03/14/2024, 14/03/2024), month-name formats (14 Mar 2024, March 14, 2024, 14-Mar-24), and two-digit years with 1970–2069 windowing.
How does it handle ambiguous dates like 01/02/2024?
It reads the whole column before changing anything. A single value with a day above 12 settles the order for every row, so a column containing 31/12/2024 is treated as day-first throughout. If every value reads validly both ways, the cleaner asks you to pick DD/MM or MM/DD rather than guessing — it will never apply two different readings within one column.
Is my file uploaded anywhere?
No. The file is parsed and processed entirely in your browser using JavaScript. It never leaves your device, and nothing is stored on our servers.