In Excel: copy the data first, select the whole table, then Data ▸ Remove Duplicates. Confirm the header setting and tick the columns that define a duplicate. Excel keeps the first matching record; UNIQUE returns a separate list of distinct rows or values.
On this page7
Make a copy, then select all columns of the records, including headers.
On the Data tab, click Remove Duplicates.
Confirm My data has headers and tick only the columns that define the comparison key.
Confirm, check the removed count, and verify which complete records remain before saving.
For a separate list on Microsoft 365 or Excel 2021/2024, use UNIQUE in an empty area and choose the input columns for the intended output.
What this does
Remove Duplicates changes the selected data in place. Its checked columns form the comparison key: checking Email alone can delete a record with a different amount, while checking Email and Amount requires both to match. Keep the full record range selected so values stay together. UNIQUE over several columns compares entire rows; it does not select the first whole record for each email address. Before you run it on a workbook other people depend on, try it on a copy or a few rows first. Undo only reaches back through the current session, so a quick trial run is the cheapest way to see exactly what will change before the file is saved and shared. For “de-duplicate in excel”, the reliable version is a short checking loop, not just the first command that appears to work. Run it on a deliberately small range first, watch how the affected duplicates change, and only then apply the same setup to the full sheet. When this is a ribbon command, the selection matters more than the button: confirm the range, apply the command, then spot-check the output before saving. That is what makes a data step that keeps your analysis trustworthy useful in real work: repeatable, auditable, and not dependent on memory or luck.
A worked example
A1:B5 has headers Email and Amount, followed by ada@example.com/10, ben@example.com/20, ada@example.com/30 and ben@example.com/20. On a copy, select A1:B5 and confirm headers. Tick Email only: Ada/10 and Ben/20 remain, with 2 records removed. Restore a fresh copy and tick both columns: Ada/10, Ben/20 and Ada/30 remain, with only 1 removed. =UNIQUE(A2:B5) in D2 returns those 3 distinct rows on supported versions; =UNIQUE(A2:A5) returns only 2 email addresses. Duplicate rows quietly inflate counts, totals and mailing lists. Removing them — or surfacing them with UNIQUE and COUNTIF — is a basic data-hygiene step before any analysis you want to trust. When the result is not what you expected, undo straight away rather than repairing it by hand — undo restores the sheet exactly, while manual fixes tend to leave small inconsistencies behind that surface later.
In Google Sheets
Function availability: UNIQUE: Excel 2021+. These are Microsoft's version markers; earlier perpetual releases do not include these functions. Check the actual product and update channel before using the formula. A marker does not establish an identical Web/Mac workflow or Google Sheets support. Nothing on this page is behind a login or a download: the exact answer is at the top, and the detail below it is there for when you need it. That is the whole promise here — the answer first, and just enough context to make it stick. Here is the takeaway for “de-duplicate in excel”: follow the steps at the top, check the result on the sheet itself, and keep undo in mind while you experiment. Done once deliberately, it becomes something you do from memory in Excel rather than something you search for again.
Common mistakes
- Selecting only one column, so Remove Duplicates shrinks that column out of step with its row.
- Forgetting it edits in place — make a copy first if you might need the duplicates back.
- Ticking every column when only one (like an ID) actually defines a duplicate.
- Treating
UNIQUEover the entire table as equivalent to removing duplicates by one selected key. - Overlooking stray spaces or different display formats; inspect the compared cells before changing the data.
Frequently asked questions
Remove Duplicates or UNIQUE?
Remove Duplicates changes the selected records and keeps the first match for the checked columns. UNIQUE returns a live separate array of distinct rows or values. UNIQUE(A2:B5) compares both columns, not just the email key.
How do I find duplicates without deleting them?
Use Conditional Formatting ▸ Highlight Cells ▸ Duplicate Values to colour them, or =COUNTIF(range, cell)>1 to flag them.
Why are visible duplicates not removed?
Check the selected comparison columns, stray spaces and cell display formats. A difference in another checked column is enough to keep the row. Inspect the key before cleaning or deleting records.