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Remove Duplicates in Excel — Online Excel/CSV Deduplication, Column Rules, Local Processing
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Fast, privacy-first deduplication for Excel (.xlsx) and CSV. Select columns as unique keys, configure keep-first/keep-last strategy, and normalize text (trim, lower-case, punctuation, full-width→half-width) before removing duplicates. Runs fully in your browser with preview, progress, and one-click download to Excel/CSV.

Features

Excel/CSV Support
Multi-Column Keys
Keep First/Last
Text Normalization
Local Processing
Preview & Progress
One-click Download
Internationalization
+1 more features

Usage Examples

Basic Usage

Remove Duplicates in Excel — Quick Start

Usage Steps:

  1. Upload — Select an Excel (.xlsx) or CSV file. The tool analyzes headers, sample values, and row count locally.
  2. Choose Columns — Tick one or more columns as the unique key for duplicate detection (e.g., Email + Phone).
  3. Set Options — Choose 'Keep First' or 'Keep Last'; enable normalization like Trim/Lower-case/Punctuation/Full→Half Width.
  4. Run — Start processing. View progress and summary: original rows, duplicates removed, unique rows retained.
  5. Download — Export the cleaned dataset to Excel or CSV with a single click.

Features:

  • Multi-Column Deduplication — Combine columns to define row uniqueness
  • Keep Strategy — Choose to keep the first or last occurrence of duplicates
  • Normalization — Trim whitespaces, convert to lower-case, normalize punctuation, full-width→half-width
  • Local-first — All processing stays in the browser; no server upload
  • Result Summary — See counts of original, duplicate, and unique rows
  • Export — Download to .xlsx or .csv instantly

Use Cases:

  • Email List Cleaning — Remove duplicate subscribers across merged lists
  • Sales CRM Merging — Deduplicate leads by Email + Phone or Company + Name
  • Event Registrations — Clean attendee sheets before badge printing
  • Product Catalog — Collapse duplicate SKUs while keeping latest updates
  • Academic Datasets — Ensure unique participants or records by ID
  • Finance Exports — Normalize payee names and remove duplicate transactions

Common Questions (Q&A):

  1. Q: How do I remove duplicates by multiple columns in Excel?
    A: Select all relevant columns as the unique key (e.g., Email + Phone). The tool treats rows with identical values across these columns as duplicates.
  2. Q: What is the difference between 'Keep First' and 'Keep Last'?
    A: 'Keep First' preserves the first encountered row among duplicates; 'Keep Last' keeps the most recent occurrence if your data is time-ordered.
  3. Q: Is my file uploaded to a server?
    A: No. All parsing, normalization, and deduplication happen locally in your browser for maximum privacy.
  4. Q: Will normalization change my data permanently?
    A: Normalization affects how duplicates are detected. The exported result reflects the cleaned values so your dataset stays consistent.
  5. Q: Which output format should I choose, Excel or CSV?
    A: Choose Excel (.xlsx) to preserve formatting and wide compatibility; choose CSV for lightweight interoperability and pipelines.