Online File Comparison Tool
Use our free file comparison tool to detect mismatches across CSV, Excel, and text files. Highlight differences side-by-side online without uploading data.
About File Comparison Tool
The Doffl file comparison tool allows you to inspect differences, detect unmatched rows, and highlight mismatches between two data files side-by-side. Whether you are validating updated spreadsheets or checking exported data sets, this utility helps you spot modified, added, or deleted records quickly.
The utility processes files directly inside your web browser without sending your proprietary data to external servers. It supports structured formats like CSV and Excel, making diff checking straightforward and private with no setup or account required.
Key features
- Side-by-side visual diff highlighting for modified lines
- Column-level mismatch detection for CSV and Excel files
- Client-side processing ensures complete data privacy
- Instant identification of added, removed, and changed rows
- Supports CSV, XLSX, and plain text formats
- Export comparison summaries and mismatched data reports
How to use File Comparison Tool
- Select or drag and drop your original file into the first panel.
- Upload the modified or target file into the second panel.
- Choose your comparison settings such as delimiter or matching columns.
- Review the highlighted additions, deletions, and cell-level mismatches.
- Export or copy the discrepancy report for your records.
Who is it for?
- Data analysts auditing differences between monthly financial reporting spreadsheets
- Developers verifying database exports against updated CSV data sets
- Operations teams checking customer lists for missing or mismatched records
- Quality assurance testers validating API responses and tabular exports
Frequently asked questions
Is my data uploaded to your servers when using this tool?
No, this tool processes files entirely in your browser using client-side JavaScript. Your data never leaves your device or transfers across external networks.
What file formats does the file comparison tool support?
You can compare CSV, Excel (XLS and XLSX), and standard text files. The tool parses column headers and structured rows automatically for spreadsheet files.
Can the tool match rows based on a specific column or key?
Yes, you can specify an identifier column like an ID or email address to align rows accurately before comparing differences across other columns.
Is this file comparison tool free to use?
Yes, the tool is completely free with no account creation or subscription required for standard comparisons.
Can I export the differences found between two files?
Yes, you can download a generated diff report or copy the unmatched and modified records directly from the interface.