Excel Guide: How to Find Duplicates

This is a practical guide on detecting duplicates in Excel—whether they appear in a single column, across columns, or as entire repeated rows. It covers various methods, including both formatting and dynamic formulas.

---

1. Objective

Goal: Identify duplicates in Excel data

• Compare same/different columns for overlapping values
• Compare entire rows for duplicate data
• Optionally flag, highlight, or return lists of duplicates using formulas

---

2. Methods to Find Duplicates

Method 1: Highlight Duplicates Across Two Columns

• Scenario: Compare two columns (e.g., product codes in segment one vs. segment two)
• Steps:
  1. Select first range (Ctrl + Shift + Down)
  2. Hold Ctrl, select range in 2nd column, select down
  3. Go to Home > Conditional Formatting > Highlight Cell Rules > Duplicate Values
  4. Choose formatting (e.g., yellow fill)
  5. Click OK—duplicates are visually highlighted
• Result: Duplicates across the two columns are easily spotted

---

Method 2: Identify Duplicate Rows

• Scenario: Find rows where all content matches another row
• Steps:
  1. Use the CONCAT function to combine row values into a "unique key" column
  2. Drag formula down to fill for each row
  3. Apply Conditional Formatting to this key column (Highlight Cell Rules > Duplicate Values)
  4. Optionally, hide the key column:
     • Right-click > Format Cells > Custom: ;;; (makes values invisible)
• Result: Duplicate rows are flagged/highlighted based on the generated keys

---

Method 3: Formulas to Return/Flag Duplicates

A. Find Duplicate Values in a Single Column

• Formula:
  =COUNTIF($B$4:$B$100, B4)
• Use with:
  • > 1 to flag duplicates (=COUNTIF(...) > 1)
  • Output TRUE (duplicate), FALSE (unique)

B. Flag Duplicate Rows

• Combine row into a unique key as above
• Use COUNTIF on the key column:
  • =COUNTIF($F$4:$F$100, F4) > 1
  • Optionally return emoji, flag, or custom text for duplicates
  • Hide helper column or group it (Shift + Alt + →)

C. Highlight Entire Duplicate Rows

• Use Conditional Formatting > New Rule > Use a formula
  • Formula checks if cell in flag column equals your chosen indicator
  • Apply desired formatting across the row

---

Method 4: Return Only Duplicate Rows (Dynamic Lists)

• Scenario: Want a filtered list of duplicates—not just highlight/flag
• Steps:
  1. Use previously created key column
  2. Use FILTER to extract rows:
     • =FILTER(DataRange, COUNTIF(KeyRange, KeyRange) > 1, "")
  3. For sorted results:
     • =SORT([Above Formula], 1)

---

3. Notes & Tips

• Conditional Formatting methods work for visual identification.
• Formula-based methods (COUNTIF, CONCAT, FILTER, SORT) provide dynamic, reusable results and can return true lists of duplicates.
• Helper columns (unique keys/flags) can be hidden or grouped to keep worksheets clean.
• Removal of duplicates is a separate task (refer to a specific video or guide).

---

4. Summary of Core Functions/Shortcuts

| Task | Function/Command | |---------------------------------|------------------------------| | Conditional formatting | Home > Conditional Formatting| | Unique key for row | CONCAT / CONCATENATE | | Count duplicates | COUNTIF | | Filter for duplicates | FILTER | | Sort results | SORT | | Hide column value | Format Cells > Custom ;;; | | Group helper columns | Shift + Alt + → |

---

5. Further Action

• To remove duplicates, refer to related tutorials or guides.
• Subscribe and engage for more Excel tips.

---

End of Guide