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MyDataFixer

Spreadsheet Error Detector

Check an Excel or CSV file for duplicate rows, missing cells, extra spaces, inconsistent dates, invalid emails and other hidden problems. Each problem is explained, many can be fixed for you after a preview, and your original file is never changed.

MyDataFixer checks your spreadsheet for common problems, explains each one, and can fix many of them for you after showing a preview. Everything happens on your device, and your original file is never changed.

Your file is read by your browser on this device. It is not uploaded to our servers.

How the Spreadsheet Error Detector works

  1. Open an Excel workbook (.xlsx or .xls) or a CSV file. It is read on your device, and a preview of the sheet appears.
  2. MyDataFixer checks every row and column for eleven kinds of problem: duplicate rows, empty rows and columns, missing cells, extra spaces, inconsistent capitalization, numbers stored as text, inconsistent, impossible or ambiguous dates, invalid email addresses, invalid phone numbers, unusual values and formula errors such as #DIV/0! or #N/A.
  3. Each problem gets a card with a count, a plain explanation, examples and advice on how to fix it. “View affected data” filters the table to exactly the rows involved.
  4. Many problems have a Fix button. You always see a preview of every change first; nothing changes until you tap Apply. “Fix all safe problems” applies only fixes that need no decision.
  5. Undo, Redo and the change history work for every fix. Download the corrected file as CSV or, for Excel workbooks, as Excel. The file is checked cell by cell before it is offered.

Example

A customer list has 2,000 rows. The detector finds 14 duplicate rows, 37 names with a space at the end, “Paris”, “paris” and “PARIS” in the city column, and a date column where most dates are written 2024-03-15 but some are 15/03/2024.

“Fix all safe problems” removes the duplicates (keeping the first copy), trims the spaces and uses the most common spelling of each city. The dates need your choice of format, so they get their own Fix button, which also asks whether 03/04/2024 means 3 April or March 4 when the column itself can't tell.

What the Error Detector never does

  • Upload your file or change the original. Fixes apply to a copy in your browser; the download is a new file.
  • Change a formula cell automatically, or run formulas. Formulas are read as text and never executed.
  • Guess when a value is ambiguous. Ties in capitalization, unclear date orders and phone layouts are asked, not guessed.
  • Remove rows or columns that anything else in an Excel workbook refers to (formulas on other sheets, charts, named ranges). It offers to clear the cells instead.

Good to know

  • Files up to 150 MB are accepted. Very large files need a computer or a recent phone with enough memory; if a file is too large for the device, MyDataFixer stops safely and says so.
  • Excel workbooks are checked one sheet at a time. Old .xls files are downloaded in the newer .xlsx format, and the page lists what that format change can't keep.
  • Automated checks can miss problems or flag values that are correct for your data. Review the results before relying on them.

Questions and answers

Is my file uploaded?

No. Your browser opens the file on your device and every check, fix and download happens there. The contents of your file are not sent to MyDataFixer's servers or to anyone else, and your original file is never changed.

Which files can I check?

Excel workbooks (.xlsx and the older .xls format) and CSV files, up to 150 MB. Password-protected workbooks can't be opened.

Will my Excel formatting be kept when I download?

Yes, when you download an .xlsx file as Excel: only the cells you changed are rewritten inside your original workbook, and formatting, formulas, charts and other sheets stay as they were. A CSV download holds values only.

Why doesn't every problem have a Fix button?

Some problems can't be fixed without knowing the right value, such as an invalid email address or an unusual number. For those, the card explains what is wrong, and you can tap the cell in the table to edit it yourself.

Can I undo a fix?

Yes. Every fix and every edited cell can be undone and redone, and the change history lists each change with the old and new value.

Does it check formulas?

It finds cells that show formula errors such as #DIV/0!, #N/A or #REF!, so you can trace them back to their source. It does not rewrite formulas.

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