Standardize CSV Dates and Numbers for Analysis-Ready Data
CSVs collected from multiple sources almost always contain the same column in three different formats — making aggregation, deduplication, and analysis error-prone. Deliteful's CSV Normalize Data Types tool resolves mixed numeric and date representations into a single consistent format across every row, so your data is ready for analysis without manual reformatting.
Data cleaning projects stall at the formatting stage more often than any other. A dataset merged from five regional sales exports might have dates as '2024-01-05', 'January 5th 2024', and '05-01-24' in the same column — all meaning the same day, all causing pivot table failures or GROUP BY mismatches. Numeric columns with inconsistent decimal notation or formatting characters cannot be summed without cleaning first. This tool handles that normalization step automatically.
Upload one or more CSVs and either name the columns to normalize or let the tool's sample-based auto-detection identify numeric and date fields. Every matching cell is rewritten to a consistent representation. Column and row order are preserved. The result is a clean CSV that loads into Excel, Google Sheets, Python, or SQL without reformatting.
How it works
- 1
Upload CSVs
Upload one or more CSV files containing mixed-format numeric or date columns.
- 2
Identify columns to normalize
List specific column names or leave blank to auto-detect numeric and date fields from a row sample.
- 3
Select your date output format
Pick ISO, US, or EU date format depending on your target tool or audience.
- 4
Download clean files
Download normalized CSVs ready for analysis, import, or reporting.
Frequently asked questions
- Can this tool handle CSVs merged from multiple sources with different date formats in the same column?
- Yes. The tool detects and parses multiple incoming date formats within a single column and rewrites them all to your chosen output format. Values it cannot confidently parse are replaced with empty cells.
- Does normalizing numeric columns remove currency symbols and thousands separators?
- Partially. Standard numeric parsing handles many common formats but does not strip currency symbols or non-standard separators — those values will become empty cells rather than being converted. For best results, specify columns explicitly and review a sample of the output before use.
- Will my column headers and row order change?
- No. Column order, column headers, and row order are all preserved exactly as in the original file.
- Is auto-detection reliable for columns that are mostly one type but have a few outliers?
- Auto-detection is sample-based and works well for mostly-consistent columns. For columns with significant mixed-type data, explicitly specifying the column name gives you full control and avoids misclassification.
Create your free Deliteful account with Google and turn messy CSVs into analysis-ready data in one step.