Fix Your Own Excel File
No Software Required
Every XLSX file is a ZIP archive containing plain XML files. That means you can open it with Windows Explorer, edit the XML with a free text editor, and fix corruption yourself. No uploads, no paid tools, no internet connection needed. This series of guides walks you through the full process from start to finish.
Who these guides are for
- Your file contains sensitive or confidential data you can't upload
- You're offline or have a slow connection
- The online tool found issues but you want to understand and fix them yourself
- Excel's "repair" deleted data you need to recover
- A third-party script generated a broken XLSX you need to fix at the source
- You just want to understand how Excel files actually work
The Guides — Best Read in Order
How to Open, Edit, and Re-Zip an XLSX File Without Breaking It
The foundation skill. Learn how to rename, open, edit individual files inside, and re-zip an XLSX correctly. Covers the one critical mistake that breaks most DIY attempts.
Start here → Guide 2The Anatomy of an XLSX File: What Every Folder and File Does
A reference map of every significant file inside an XLSX package — what it does, what breaks when it's corrupt, and which files are most likely to cause problems.
Read guide → Guide 3How to Read and Edit XML Inside an Excel File
XML looks intimidating but follows three simple rules. This guide teaches you to read any Excel XML file and make targeted edits — with three real examples.
Read guide → Guide 4Common Corruptions in workbook.xml and How to Fix Them
Sheets missing from the tab bar, named ranges throwing #REF!, file won't open. The four most common workbook.xml corruptions with exact before/after XML fixes.
Read guide → Guide 5Common Corruptions in sharedStrings.xml and How to Fix Them
The file most often hit by a mid-save crash. Text cells showing nothing or the wrong values almost always trace back here. Three corruption types with fixes.
Read guide → Guide 6Common Corruptions in styles.xml and How to Fix Them
Formatting vanishes after repair, or cells display wrong colors and fonts. Often caused by out-of-range style indexes or missing required fill entries. Four types covered.
Read guide → Guide 7Common Corruptions in sheet1.xml and How to Fix Them
The hardest file to fix because it's the largest. Five corruption patterns — invalid cell addresses, out-of-order rows, broken formulas, merge cell errors, and orphaned tags.
Read guide →