Remove Duplicate Lines in Excel, Google Sheets, Notepad & Online

Duplicate lines appear everywhere: exported CSVs from your CRM, copy-pasted keyword lists, email subscriber exports, log files. The method you use to remove them should match the context. Here's the fastest approach for each tool you're likely using.

Method 1: Remove Duplicates in Excel

Excel has a built-in deduplication tool:

1. Select your column of data.
2. Go to Data tab → Remove Duplicates.
3. Make sure only your column is checked → click OK.

Excel removes duplicates in-place and shows a summary of how many rows were removed. This works on entire rows too — useful for deduplicating a full spreadsheet based on one or multiple columns.

Limitation: it modifies the original data. If you want to keep the original intact, copy to a new sheet first.

Method 2: Remove Duplicates in Google Sheets

Google Sheets has a native Remove Duplicates feature:

1. Select your data range.
2. Go to Data → Data cleanup → Remove duplicates.
3. Choose which columns to check for duplicates → Remove duplicates.

Like Excel, this modifies in place. For a non-destructive approach, use a UNIQUE formula: =UNIQUE(A:A) in an empty column. This returns all unique values from column A without touching the original.

Method 3: Remove Duplicate Lines in Notepad++

Notepad++ (free download for Windows) can deduplicate lines:

1. Open your file in Notepad++.
2. Go to TextFX → TextFX Tools → Sort lines case sensitive (at column) + Remove duplicate lines.

If TextFX isn't installed: Plugins → Plugins Admin → search TextFX → Install. Note that this also sorts the lines alphabetically — if you need to preserve order, use the online method instead.

Method 4: Free Online Duplicate Line Remover

For plain text lists — keyword lists, URLs, product IDs — an online tool is the fastest option. No software, no formulas, no sorting side effects:

1. Paste your list into the input box.
2. Duplicates are removed instantly; result appears on the right.
3. Click copy.

The tool preserves the original order of lines, keeping only the first occurrence of each duplicate. This is the key advantage over Notepad++ (which sorts) and Excel (which also removes based on sort order in some configurations).

Which Method Should You Use?

Choose based on context:

• Data in a spreadsheet already: Use Excel or Google Sheets native tool. Fast, integrated, records the operation.
• Large file, need formula output: Use UNIQUE() in Google Sheets or Power Query in Excel.
• Plain text list, one-off task: Online tool. No file to open, no software needed, result is instantly copyable.
• Log file or code, need order preserved: Online tool or command line (awk '!seen[$0]++' on Unix).

Frequently Asked Questions