How to Clean Data in Power Query — Step by Step

Power Query is one of the most important skills every data analyst needs — because messy data destroys reports. In this video, I’ll show you exactly how to clean and transform data in Power Query step by step, using real examples beginners struggle with every day. If you’ve ever imported a dataset into Power BI and didn’t know what to fix first, this walkthrough will make the process finally make sense. ⏱️ Timestamps 0:00 — Why Dirty Data Breaks Power BI Reports 0:24 — What You’ll Learn in This Video 0:53 — Opening Power Query in Power BI 1:41 — Understanding the Region Column Problems 2:14 — How Applied Steps Work in Power Query 2:40 — Why Power Query Is Non-Destructive 2:48 — Step 1: Removing Blank Rows 4:17 — Step 2: Removing Duplicate Records 5:54 — Why Duplicate Data Causes Reporting Errors 6:00 — Step 3: Removing Unnecessary Columns 6:42 — Step 4: Renaming Columns Consistently 7:29 — Why Naming Conventions Matter for DAX 7:38 — Understanding Snake Case Naming 9:15 — Step 5: Fixing Inconsistent Text Values 9:31 — The Power BI Slicer Problem Beginners Miss 9:57 — Using Capitalize Each Word 10:21 — Step 6: Trimming Leading & Trailing Spaces 11:13 — Step 7: Fixing Data Types 11:29 — Why Incorrect Data Types Break Calculations 12:24 — Setting Decimal Data Types Correctly 13:03 — Handling Null Values Properly 13:18 — Three Ways to Handle Missing Data 13:43 — Replacing Null Values with Zero 14:35 — Using Close & Apply 14:59 — Reviewing the Final Clean Dataset 15:21 — The 7-Step Data Cleaning Recap 15:45 — Why Clean Data Builds Trust 16:18 — What to Learn Next in Power BI In this video: how to clean messy datasets in Power BI using Power Query, including fixing data types, removing duplicates, handling null values, transforming columns, and preparing data for professional dashboards. 🎁 Free Data Analyst Career Roadmap — every step from Excel to employed: https://datacareermastery.com/data-ca... Data with Arlen is the channel for aspiring data analysts and business analysts who want to build real Power BI, SQL, and Excel skills — and learn how to work with data like a professional. New videos every week. #powerquery #powerbi #datacleaning #powerquerytutorial #powerqueryforbeginners #powerbitutorial #dataanalyst #businessintelligence #datatransformation #powerbidesktop #excel #sql #datavisualization #dataanalytics #datawitharlen