Free Online CSV Diff
Visualize every cell-level discrepancy instantly as CSV Diff highlights differences between your files side by side. Upload your original and modified CSV files, paste data directly into the editor panels, or drag and drop files onto the workspace. After parsing your data with your preferred delimiter, the engine aligns rows and applies color-coded markers to show exactly what was added, removed, or changed. Changed cells display both the old and new values so you can see exactly what was modified. Choose from six specialized comparison modes, such as cell-by-cell diff, row diff, column analysis, and more, to get the exact view you need.
CSV Diff
Compares two CSV files cell by cell with color-coded highlighting for identical, changed, added, and removed values.
Row Diff
Identifies rows that exist only in File A, only in File B, or in both using set-based comparison.
Column Diff
Compares column headers between files and counts value differences in shared columns.
Stats Diff
Shows row counts, column counts, total cells, empty cells, and character counts side by side with deltas.
CSV Merge
Combines two CSV files by appending unique rows from File B to File A, skipping duplicates.
CSV Intersect
Extracts rows that appear in both files, producing a dataset of shared records.
Online CSV Diff with Cell-Level Change Detection
Comparing CSV files manually by scrolling through rows and columns is tedious and error-prone. CSV Diff streamlines this workflow by automatically parsing your files, aligning rows, and flagging every change with clear visual cues. Identical rows stay white, changed rows highlight in amber with old values shown as struck-through text, added rows appear green, and removed rows display in red. Navigate even the largest datasets with ease using the scrollable results table and sticky headers that keep your data in context.
Upload Files or Paste Data
Getting your data into the tool is simple: upload via the button, drag and drop your .csv, .tsv, or .txt files, or paste your data directly into the workspace. Both panels work independently so you can upload one file and paste data for the other. Your files stay on your device because all parsing and comparison happen locally in the browser.
Flexible Delimiter and Comparison Options
Not every CSV uses commas. Pick your preferred delimiter from the options bar, choosing between comma, semicolon, tab, or pipe before you begin. You can enable "Ignore case" to treat uppercase and lowercase letters as equivalent, or toggle "Trim whitespace" to strip extra spaces. Your selected settings automatically apply across all six comparison modes for a seamless experience.
Row, Column, and Statistical Comparison
Gain deeper insights into your data with four additional modes that offer different perspectives on your CSV changes. Row Diff uses set comparison to identify rows unique to each file and rows they share, regardless of row order. Column Diff compares header names to find structural changes like added or removed columns, then counts value differences within shared columns. Stats Diff provides a high-level overview by comparing row counts, column counts, total cells, empty cells, and character counts side by side with deltas.
Merge and Intersect Datasets
Consolidate your datasets effortlessly with CSV Merge, which appends unique rows from File B to File A while filtering out any duplicates. Duplicate detection uses the full row content as a key, so only truly unique rows are added. Use CSV Intersect to isolate the overlap between your files, generating a clean dataset containing only the shared records. Both tools output standard CSV that you can copy or download.
Copy and Download Results
Save your results in seconds by copying to your clipboard or downloading a new CSV file with a single click. When you export a cell-level diff, it uses a prefixed format where status symbols like plus, minus, and tilde indicate the specific change for each row. Text-based results from Row Diff, Column Diff, Stats Diff, Merge, and Intersect export as-is.
Your CSV Data Never Leaves Your Browser
CSV files often contain sensitive business data, customer records, or financial information. Everything happens right on your device using browser-native JavaScript, ensuring total privacy for your data. No server requests, no uploads, no cookies, and no account required. Close the browser tab and your data is gone. The comparison engine handles quoted fields, escaped quotes, and multi-line values according to RFC 4180.
Related CSV and Data Tools
If you work with CSV files regularly, these tools complement what you can do here:
- CSV to JSON -- convert CSV data to JSON format
- CSV to HTML Table -- render CSV as an HTML table
- CSV to Multiline -- split CSV values, extract columns, filter rows, and more
- JSON Formatter -- format, minify, validate, and transform JSON data
- XML Formatter -- format and beautify XML documents
- SQL Formatter -- format and beautify SQL queries