Find & Remove Duplicate Rows in Excel
Upload your Excel file, choose which columns to compare, and instantly see every duplicate row — with a preview table and a one-click download of the clean deduplicated file.
Drop your Excel file here
or click to browse — .xlsx and .xls supported
Processed entirely in your browser — files never uploaded to any server
How to Find Duplicate Rows
Upload your file
Drag and drop your .xlsx or .xls file, or click to browse.
Choose columns
Select which columns to use for comparison. A row is a duplicate only if all selected columns match.
Find duplicates
Click Find Duplicates — see a colour-coded table with every duplicate highlighted.
Download clean file
Download the deduplicated file with all duplicates removed in one click.
What Makes This Tool Accurate
Duplicate detection sounds simple, but real-world data has subtleties that basic tools miss. This tool handles them correctly:
- Column-level control: You choose which columns define uniqueness. An "Email" duplicate means the same email — other columns can differ. A "Full name + Company" duplicate requires both to match.
- Case-insensitive matching: "Smith" and "SMITH" are the same person. Enable this option (on by default) so capitalisation differences don't hide duplicates.
- Space normalisation: Extra spaces around values are a common cause of missed duplicates — "London " and "London" look identical on screen but are technically different strings. This option catches them.
- Two downloads: Get the clean file (duplicates removed, first occurrence kept) or the duplicates-only file (for review or record-keeping).
- Full transparency: The colour-coded table shows every row's status — Original, Duplicate, or Unique — so you know exactly what will be removed before you download.
Frequently Asked Questions
How does the duplicate finder decide what counts as a duplicate?
Two rows are duplicates if the values in all selected columns match exactly (or match after ignoring case/spaces, if those options are enabled). You control which columns are checked — if you select only the "Email" column, rows with the same email are flagged even if other columns differ.
Are my files uploaded to a server?
No. Your file is processed entirely in your browser using JavaScript. It never leaves your device and is never sent to any server. You can use this tool offline after the page loads.
Which occurrence is kept — the first or the last?
The first occurrence of each duplicate group is kept in the clean download. All subsequent occurrences are removed. In the results table, the first occurrence is marked "Original" and subsequent ones are marked "Duplicate".
Can I find duplicates across multiple sheets?
Currently the tool checks one sheet at a time. Use the sheet selector to switch between sheets. Cross-sheet duplicate detection is on our roadmap.
What does "ignore case" mean?
With "ignore case" enabled, "London" and "LONDON" and "london" are all treated as the same value for duplicate matching. This catches duplicates that differ only in capitalisation.
My data has extra spaces. Will the tool still find duplicates?
Yes — enable the "Ignore leading/trailing spaces" option. This means "London " (with a trailing space) and "London" will match as duplicates. This option is on by default.
This Tool vs Excel's Built-in “Remove Duplicates”
| Feature | Excel Remove Duplicates | This Tool |
|---|---|---|
| Preview before deleting | No — deletes immediately | Yes — colour-coded preview of every duplicate |
| Download duplicates-only list | No | Yes — download just the duplicates for review |
| Undo after removal | Only if you press Ctrl+Z immediately | Original file is untouched; you download a new file |
| Case-insensitive matching | No | Yes (toggle on/off) |
| Whitespace-tolerant matching | No | Yes — "London " = "London" |
| Cross-sheet detection | No | Planned (currently one sheet at a time) |
| Works on files without Excel | No — requires Microsoft Excel | Yes — any modern browser, no Excel installed |
| Overwrites original file | Yes (unless you undo) | Never — always downloads a new file |
Common Duplicate Detection Use Cases
Duplicate row removal is one of the most frequent data cleaning tasks across industries:
- CRM and contact lists: Sales teams often end up with the same contact imported from multiple sources (website forms, trade shows, LinkedIn exports). Match on Email column to find exact duplicates; use case-insensitive + whitespace-tolerant matching to catch “john@company.com” and “John@Company.com”.
- Email marketing lists: Before an email campaign, deduplicate your subscriber list by Email address. Sending to duplicates wastes quota and risks being flagged as spam.
- Inventory and product catalogues: When merging SKU lists from multiple suppliers or systems, match on Product ID or SKU to find items that appear more than once with different pricing.
- Financial transaction records: Bank exports and accounting systems sometimes duplicate rows around month-end or system cutover points. Match on Transaction ID + Date + Amount to catch true duplicates without flagging legitimate same-day same-amount transactions.
- Survey and form responses: Find respondents who submitted the same form more than once, or multiple employees who reported the same issue.
The key to effective deduplication is choosing the right columns. Matching on all columns catches only identical rows. Matching on just one key column (like Email) finds functional duplicates even when other fields differ.