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Data Import Mapper & Validator
Make spreadsheet data ready for new software. Find missing, inconsistent and repeated information, then download cleaned records, a reusable column map and validation code.
Works in your browser. No account. Your inputs stay on this page unless you choose to save or download them. Privacy details
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A few simple steps
How it works
- Choose a CSV, tab-separated or Excel file. The tool reads the first worksheet and shows sample values without uploading the file.
- Choose which columns to keep, give them useful names and set simple rules for missing values, formats, allowed values and repeats.
- Review every rejected row, then download the cleaned CSV, rejected records, complete issue report, column map and starter validation code.
Start with an example
The workspace includes fictional examples you can replace with your own details:
- customer import
Choosing another example asks before replacing your work. Save a JSON copy first if you want to keep it.
Where clean data helps
Preparing records early reduces surprises in manufacturing systems, logistics platforms, healthcare applications and financial software. For an older application, see our approach to legacy software modernization.
What to know before you use the result
- The tool checks the first worksheet in an .xlsx file. Save another worksheet as its own file if that is the data you need.
- Type checks are deliberately strict. Dates use YYYY-MM-DD, numbers cannot contain currency symbols, and phone checks accept common punctuation without judging whether a number is active.
- Columns with the same output name are joined with a single space and must be treated as text. This is useful for fields such as first name plus last name.
- The cleaned CSV contains only rows that pass every selected rule. Text that could run as a spreadsheet formula is prefixed with an apostrophe in CSV exports. Keep the original file and review rejected records before using the result in another system.
Keep your original files. Browser storage can be cleared by your browser or another person using this device.
Good to know
Does Essential Designs receive my spreadsheet?
No. The file is read and processed in your browser. It is sent nowhere unless you later choose to share a downloaded result yourself.
Can the generated code be used without review?
Treat it as a tested starting point. A developer should connect it to your import flow, add business-specific rules and test it against representative data.
Make it your own
Source code & developer documentation
The downloadable kit contains all four tool workspaces, shared models, local export adapters, examples and CLI. It excludes the private Essential Designs website and brand assets.
Need help moving data into new software?
We can map legacy records, build a repeatable import process and connect validation to the systems your team uses.