I have messy data in a spreadsheet. Help me clean it.

Here are 10 sample rows:

"""

[paste sample rows]

"""

Problems I see: [duplicates / mixed date formats / extra spaces / inconsistent capitalization / phone numbers in different formats]

Give me a numbered cleaning plan for [Excel / Google Sheets] using built-in features and formulas (TRIM, PROPER, TEXT, Remove Duplicates, Find & Replace). Show the formula for each step and the expected result on my sample rows. Tell me what to check manually.

How to use this prompt

  • Paste only a small sample, not the whole file.
  • Follow the steps on a copy of your sheet, never on the original.
  • Compare row counts before and after.

Example

Sample dates like "5/10/26", "10 May 2026" and "2026-05-10" are turned into one standard format with a TEXT or DATEVALUE formula.

Tips for better results

  • Remove personal data such as phone numbers before pasting samples.
  • Ask "write this as an Apps Script / VBA macro" if you repeat the task every week.

This prompt works with ChatGPT, Google Gemini, Claude, Microsoft Copilot and most other AI chat tools. Replace everything in [brackets] with your own details. AI can make mistakes, so check important facts before you rely on them, and never paste private or confidential information.