Deduplicate Excel Files Online
Remove duplicate rows from Excel files instantly in your browser. No upload, no server — 100% private.
How to deduplicate Excel files
- Drop your file onto the upload area. It is loaded into the in-browser engine and the first 200 rows are shown.
- Choose the columns that define a duplicate. All columns are ticked by default, which removes only rows that are identical in every field.
- Untick columns to match on a subset. For example, keep only customer_id ticked to keep one row per customer.
- Click Deduplicate. The tool reports how many rows were removed and previews the result.
- Download the cleaned file in the same format you uploaded.
Your file is processed locally in your browser and is never uploaded. The free limit is 50 MB per file; larger files work if your device has the memory for them.
Worked example
A CRM export lists the same contact more than once because the sync job ran twice, and one person also signed up again later with a different date.
Input (Excel)
Excel workbook, first sheet (Sheet1)
| name | plan | signup_date | |
|---|---|---|---|
| ana@example.com | Ana Ruiz | pro | 2026-01-04 |
| ben@example.com | Ben Cho | free | 2026-01-09 |
| ana@example.com | Ana Ruiz | pro | 2026-01-04 |
| cara@example.com | Cara Doyle | free | 2026-02-11 |
| ben@example.com | Ben Cho | pro | 2026-03-20 |
Settings
- Columns to match on: email only (name, plan and signup_date unticked)
Result
| name | plan | signup_date | |
|---|---|---|---|
| ana@example.com | Ana Ruiz | pro | 2026-01-04 |
| ben@example.com | Ben Cho | free | 2026-01-09 |
| cara@example.com | Cara Doyle | free | 2026-02-11 |
Matching on email alone collapses five rows to three: one row per address. With all columns ticked, only the exact repeat of Ana's row would be removed. Ben's two rows would both stay because his plan and signup date differ. Which row survives for each email is not guaranteed, so sort first if you need the earliest or latest one.
Working with Excel files
The tool reads the first sheet of the workbook, and most cells come in as the text Excel displays. That means formatting matters. A cell showing "$1,200.00" and a cell showing "1200" are different values here, even if both hold the number 1200. Formulas are read as their last calculated result, not the formula text.
Date cells are the exception. A cell with an Excel date format loads from its stored value, so "3/2/26" in one row and "2 March 2026" in another both become 2026-03-02 and match. Dates typed as text are compared as typed, and a date left in General format arrives as a serial number such as 46083, so neither matches a real date cell for the same day. Before deduplicating, give key number columns one consistent format in Excel, or clean them with Find & Replace, and convert text dates with Parse Dates. Merged cells and blank spacer rows also create near-duplicates, so check the preview before you download the cleaned .xlsx file.
Frequently Asked Questions
Is this the same as Excel's Remove Duplicates button?
It works the same way: tick the columns that define a duplicate and one row per combination is kept. It runs in your browser without Excel and handles files with more rows than Excel's 1,048,576-row limit if you download to CSV or Parquet.
Which sheet of my Excel file is deduplicated?
The first sheet. For another sheet, extract it first with the Excel Sheet Extractor, then deduplicate the result.
Which row is kept when duplicates are found?
One row per unique combination of the selected columns is kept. When you match on a subset of columns, which of the matching rows survives is not guaranteed. Sort the file first if you need the earliest or latest one, or use Top N per Group with N = 1.
What is the difference between Remove Duplicates and Find Duplicates?
Remove Duplicates writes a cleaned file with the extra rows dropped. Find Duplicates lists which rows are duplicated and how many times each one appears, so you can review them before deleting anything.
Can it catch near-duplicates such as typos in names?
No. Matching is exact. Use Fuzzy Deduplicate for names or addresses that differ slightly, such as "Acme Ltd" and "ACME Limited".
Related Tools
Find Fuzzy Duplicates in Excel Files Online
Find near-duplicate rows in Excel files using Levenshtein edit distance or Jaro-Winkler similarity — all in your browser. Set your own threshold and download the matched pairs as CSV — no upload required.
Count Values in Excel Files Online
Group and count rows by any column in Excel files directly in your browser. Sort by frequency or value to find the most common entries — no upload required.
Sort Excel Files Online
Sort Excel files by any column, ascending or descending, directly in your browser.
Deduplicate CSV Files Online
Remove duplicate rows from CSV files instantly in your browser. No upload, no server — 100% private.
Deduplicate Parquet Files Online
Remove duplicate rows from Parquet files instantly in your browser. No upload, no server — 100% private.
Deduplicate JSON Files Online
Remove duplicate rows from JSON files instantly in your browser. No upload, no server — 100% private.
Excel Viewer Online
View and inspect Excel files directly in your browser. Browse rows, check column names and data types — no upload required, your data stays on your device.
Convert Excel to Parquet Online
Convert Excel files to Parquet format directly in your browser. No upload required — your data never leaves your device.