MyClawn Data › Remove duplicates
Remove duplicates in Excel: do it yourself, or send it over
Excel has a built-in Remove Duplicates command. It works when rows are identical. This page shows how to use it, where it fails, and when it is faster to send the file to be cleaned.
The built-in way
In Excel, select your data, open the Data tab and choose Remove Duplicates. Pick the columns that define a duplicate, for example just Email, and confirm. Excel keeps the first row it finds and deletes later matches. Do this on a copy of your sheet, because the deletion cannot be told which of two near-identical rows is better.
It compares cell values as they are. That is where messy lists go wrong.
Why real lists defeat it
| Problem | Example | Why Remove Duplicates misses it |
|---|---|---|
| Capitalization and spacing | JOHN SMITH and John Smith | Differences in extra spaces can make rows look different |
| Name formats | Smith, John and John Smith | Different text, same person |
| Phone formats | (555) 123-4567 and 555.123.4567 | Different text, same number |
| Date formats | 3/4/2026 and 2026-03-04 | Different text, same day |
| Which row to keep | Two rows with the same email, one with a phone number | It keeps the first, not the richer row |
The fix is to standardize first, then dedupe. Doing that by hand across thousands of rows is the slow part.
Drop your files here. Starter $29/mo · Pro $99/mo. Refund within 14 days if it misses.
Upload your filesWhat we do with your file
Upload the Excel or CSV file and write the rules in plain words: Remove duplicates by email. Split Name into First and Last. Fix capitalization. Phone as (555) 123-4567. Dates as YYYY-MM-DD. You get an Excel file back with the cleaned table, plus a Review sheet for anything it could not safely change, with the reason. Rules that are ambiguous, such as two rows with the same email but different companies, are best settled in the note: say which row wins, or ask for those rows to be flagged.
What cleanup covers
- Remove duplicate rows.
- Fix capitalization of names, companies and addresses.
- Split full names into first and last.
- Standardize phone numbers and dates to one format.
- Keep the rest of your columns as they are.
It works on what you uploaded. It does not verify that emails or phone numbers work and does not fill in missing contacts by researching the web. For researched lists see MyClawn Leads on its own site.
A worked example
A list of 3,000 trade-show contacts comes from three scanners and one hand-typed sheet. The same person appears as ANNA LEE, Anna Lee and Lee, Anna, with two phone formats and one email in capitals. Remove Duplicates on all columns removes almost nothing. The workable rule is: lowercase the email, treat it as the key, standardize names and phone numbers, then keep one row per key, preferring the row with a phone number. That is the kind of rule you write in one sentence in the note, and it is applied to the whole file with the changes reported.
Checking the output
After cleanup, check three things: the row count (the Review sheet and summary say how many rows were removed), a few merged duplicates (spot-check that the kept row is the one you wanted), and the standardized columns (sort by name and scan). Keep your original file untouched so you can compare.
When to do it yourself instead
If the list is a few hundred rows and the duplicates are exact, use the Data tab command and do not pay for anything. If the list is large, comes from several systems, or has mixed formats, the cleanup is a job. Files up to 300 MB each, 50 files per batch, $29 a month on Starter, two rounds of changes, 14-day refund. See pricing and how it works.
Upload your files and name your columns. Nothing is charged until you check out, you get two rounds of changes per batch, and there is a 14-day refund if the result misses.
Questions
Does Remove Duplicates keep the first or last row?
It keeps the first occurrence it finds, and deletes later ones.
Can the cleanup keep the row with more data?
Say so in your note, for example keep the row that has a phone number, and it is applied.
Drop your files here. Starter $29/mo · Pro $99/mo. Refund within 14 days if it misses.
Upload your files