Practical Tips
A collection of practical tips for using DiffMate more efficiently.
📁 File Preparation Tips
Unify Encoding Before Comparing
If two files have different encodings (UTF-8 vs EUC-KR), unnecessary differences may appear. Unify to the same encoding (UTF-8 recommended) before comparing.
Same Sheet Structure for Excel
XLSX comparison uses the first sheet. If the data you want to compare is on a different sheet, save that sheet as a separate file first.
Check CSV Delimiters
Some CSV files use tabs or semicolons instead of commas. Even with a .csv extension, verify the actual delimiter. Opening in Notepad is the quickest way to check.
Ensure PDFs Are Text-Based
Scanned image PDFs cannot have text extracted. Use Adobe Acrobat or a free OCR tool to add a text layer before comparing.
Include Version Info in Filenames
Include date or version in filenames to avoid confusion. Example: Report_v1_0301.xlsx, Report_v2_0305.xlsx
Extract Only Needed Sections for Large Files
Comparing entire CSV files with 1M+ rows can take time. Extract only the suspected changed range for faster comparison.
⚡ Speed Optimization
Close Unnecessary Tabs
DiffMate uses browser memory. Having many tabs open can cause memory issues. Close other tabs when comparing large files.
Use Chrome or Edge
Web Worker and virtual scrolling performance is best optimized in Chromium-based browsers. Chrome or Edge is recommended for large files.
Check File Size Beforehand
Files under 10MB compare almost instantly. 50MB+ may take a few seconds, and 100MB+ can take 30 seconds to a minute.
Remove Empty Rows
Unnecessary blank rows in CSV or TXT files make comparison results messy. Remove blank rows before comparing for cleaner results.
🔍 Result Review Tips
Understand Color Codes
Green = added lines, Red = removed lines, Orange = modified lines, Gray = moved lines. Focus on orange (modified) and red (removed) first.
Use the Minimap for Overview
The right-side minimap shows the distribution of changes at a glance. Click on concentrated color bands to jump directly to that section.
Use Character-Level Highlighting
Modified lines (orange) show exactly which characters changed in red. Even a single digit change is highlighted.
Synchronized Scrolling
Left and right panels scroll in sync. Scrolling one side automatically moves the other to the corresponding position.
Check the Change Summary
The top of results shows a summary of added/removed/modified line counts. Get the big picture first, then dive into details.
✏️ Editing & Saving Tips
Selective Changes with Arrow Buttons
Click the arrow (← →) button on any changed line to copy just that line between sides. Apply only the changes you need.
Be Careful with Bulk Apply
"Apply all changes" affects everything at once. For partial changes, use individual arrow buttons instead.
Final Check Before Saving
Before saving, scroll through once more to verify no unintended changes were made.
Remember: Files Save as TXT
Modified files download in TXT format. To restore the original format (XLSX, PDF, etc.), separate conversion is needed.
🔒 Security Tips
Verify No Server Upload
DiffMate runs 100% client-side. Open the Network tab (F12 → Network) to verify no file data is transmitted.
Works Offline Too
Once loaded, you can disconnect from the internet. For extremely sensitive documents, turn off Wi-Fi while comparing for extra safety.
Clear Browser Cache After
After comparing sensitive files, clear your browser cache. Ctrl+Shift+Delete is the quickest way.
Use Incognito on Shared PCs
When comparing on shared or public computers, use Incognito/Private mode. All data is automatically deleted when the window closes.
💼 Scenario-Specific Tips
Contracts: Check Key Clauses First
When comparing PDF contracts, first check if amounts, dates, party names, and termination conditions have changed.
Data Migration: Verify Row Counts First
After CSV/Excel migration, first confirm total row counts match, then check content differences.
Code Review: Ignore Whitespace Changes
When comparing source code, skip lines with only indentation changes and focus on actual logic modifications.
Report Review: Focus on Number Changes
When comparing report revisions, focus on character-level highlights where numbers changed. Catch unit and decimal point errors.
Periodic Reports: Compare with Previous
For periodic reports, compare with the previous period to check for missing items or abnormal figures.