Best CSV diff tool to compare two CSV files and instantly view the diffs

Compare two CSV files and get the difference online is the best performing CSV diff tool to compare CSV files online. xlCompare application is an ultimate desktop CSV diff tool to compare and merge CSV, XLSX and XML files for users who need a professional solution. xlCompare is a git diff and merge tool for Excel and CSV files.
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Remove Duplicate RowsDedup
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Remove Duplicate RowsDedup
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Common Rows
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Open two CSV files and get the difference online is online application that allows you to open and compare two CSV files, highlight the differences, export duplicate, similar(matching) and mismatching(unique) rows into third file. If you need to quickly check two CSV files for differences online without installing applications - you are in the right place. xlCompare will do this job for you!

Step-by-step Instruction

  1. Select your CSV files in the FILE1 and FILE2 panels using OPEN button.
  2. Select Primary Keys and Heading Rows, if you are working with database tables or lists of data.
  3. Use Compare Tables button to get the report.

Online CSV File Compare Tool (F.A.Q.)

Online service to compare Excel and CSV files for difference allows you to:
  1. Visually see the difference between two CSV files.
  2. Compare CSV files by Key. This is a must have option for most of the databases.
  3. Compare Columns in the CSV files. VLOOKUP command allows to compare two or more columns on the Excel sheets. This makes it more suitable than the original VLOOKUP worksheet function in Excel, that compares only one columns at a time.
  4. Filter unique, updated, and duplicate rows between two CSV files.
  5. Export visible portion of rows into the Excel or other application by using Copy button.
  6. Save differences into third file using the Export feature described above.
Copy button exports visible rows into the HTML format, that can be pasted into Excel workbook or into Word application.
Online CSV diff tool is very easy in use. We've created it to provide quick method to check two CSV files for differences, if you are not ready to use professional tool for this.
To compare two CSV files online and get the difference do the following:
  1. Open your CSV files in the FILE1 and FILE2 panels, or Paste your table right into the worksheet area.
  2. if your files have multiple sheets, Select two Excel sheets you want to compare.
  3. If your table has headings, Select key columns and heading rows
  4. Click the Compare Tables button to get the difference report on this page.
IMPORTANT: Your files are not uploaded into Internet! All operations are executed on your computer in your browser.
We respect your privacy!
Results of the comparison appear in the separate panel below the compared spreadsheets.
Report area contains Legend that shows number of differences by type and allows you to filter rows on the sheet.
What does VLOOKUP button?
VLOOKUP command is used to compare columns in two Excel sheets online.
Look into the topic below to see more information on using the VLOOKUP function.
Primary Keys columns are important part of the spreadsheet comparison.
xlCompare allows you to select any combinations of the Key Columns within first 5 columns
There is a key marker in the heading of the every column on the worksheet:
Click on the Marker to select this column as a Key
xlCompare highlights marker to reflect it's key state:
In addition to marker, xlCompare highlights data cells in the Primary Key column with color.
If you need to select other combination of columns as a primary key - you need to install and use desktop tool.
Desktop xlCompare tool allows to select any combination of the Key Columns.
xlCompare allows you to select heading row in your table within first 5 rows.
There is a Heading Row Marker in the row heading area, before row number:
Click on the Marker to mark this row as heading.
xlCompare highlights marker to reflect heading state of this row:
In addition to marker xlCompare highlights contents of this row with color and bold font.
This makes visual difference between heading row and other rows in table.
If your Excel table contains wide header that has more than 5 rows - you need to install and use desktop tool.
Desktop xlCompare tool allows to select any combination of the Heading Rows.
xlCompare online CSV file comparison service allows you to find matching rows between two CSV files. If you have two lists of data and need to find common records in two tables - here you will get them in a seconds.
Step by Step instruction how to get matching rows between two CSV sheets:
  1. Open your CSV files on this webpage in the FILE1 and FILE2 panels
  2. Select primary key columns and heading rows
  3. Get difference report with Compare button
  4. Apply filter Duplicate rows in the filter combobox.
  5. Copy equal rows into your Excel application using Copy button in the report window. allows you to find similar rows in two CSV files.
Use this instruction to get equal rows in two CSV sheets:
  1. Open your CSV files on this webpage
  2. If you tables have heading - select key columns and heading rows
  3. Compare two selected CSV files with Compare button
  4. Apply filter Equal rows in the Filter combobox
  5. Results area display only similar rows, found in two Excel spreadsheets
  6. If you need to save this data on disk - use Copy button in the report window to export cells into clipboard and paste them into Excel
You need to highlight the differences in two CSV files and send them by email to your colleague.
Do the following:
  1. Open your CSV files or Paste your tables into this online comparison service
  2. Select key columns and heading rows if your tables have such. This is important step to get right comparison results.
  3. Click the Compare Tables button to compare two selected CSV files
  4. highlights all edited cells with orange color in the Comparison Report
  5. Use Copy button in the Comparison Report to export table with formatting you have into email
  6. Paste this data into your email message as table with highlighted cells
  7. You can use this method to export difference report into any other Spreadsheet Application (Excel, Numbers, Libre Office, etc.)

General Questions

Primary Key Column is a column in table that is distinctive for each row.
Normaly values should be unique in this column, however xlCompare allows to compare tables with duplicate keys.
Example of the Primary Key is TAX ID, telephone number with area code or vehicle identification number (VIN), SKU ...
Heading row in the table is usually top row that contains title of the columns.
Set of heading rows define structure of the table.
Most of the database tables are exported with heading row.
For the comparison heading row is highly important, as it allows to match table columns by name.
If your table contains heading rows, you need to select it before comparing CSV files.
Online Excel and CSV file comparison service on the is free. You should not pay for it.
So, why there is Order page on the website for the free service?
Desktop xlCompare application is not free. It is sold as the permenent license (one time free), pricing and other information are available on the Order page.

No. You should not worry about it.
We value your privacy.
All operations (comparison, filtering, etc.) are executed in your browser. Spreadsheet Tools doesn't have access to your files. This online xl comparator service is safe and secure.
You can disable network connection and compare your files using this web page.

No. This is not possible.
Online xl comparator service doesn't send your data into the web. All processing is done in your browser on your computer.
Your data is not transmitted from your computer.

Yes you can. Worksheet is limited only by the capabilities of your browser and available memory. However if your file is quite large, we suggest you to install and use desktop xlCompare tool. It is capable to open and compare very large CSV files.
Contact Form is on the bottom of this page. Please, use it to send us your enqueries.
Also, we will be happy to see your feedback in the comments section on this page.

Compare columns in CSV files with VLOOKUP

How to compare columns in the CSV files using VLOOKUP command
In short VLOOKUP command on the checks for the presence of the value from FILE2 in the FILE1.
Use this command when you need to compare only two (or more) columns for matching values, without comparing other cells in the worksheets.
Data you are working with can be different structure in the FILE1 and FILE2.
  • VLOOKUP command in xlCompare works similar to VLOOKUP worksheet function in Excel. But there is a significant difference, VLOOKUP searches for a single value, while our service can search other worksheet for a combination of values.
  • FILE1 is treated as vocabulary.
  • FILE2 is treated as data file.
  • xlCompare gets values from the selected columns in the FILE2 and searches for these values in the selected columns in FILE1.
  • Rows with values, that are not present in FILE1 are marked with red color in the result panel.
  • Cells in the other columns are not compared.
  • VLOOKUP command compares only cells in the selected columns!
IMPORTANT: to use VLOOKUP command you need to select columns on both worksheets.
Look into next topic to get instructions on how to select columns for the VLOOKUP command.
Example of using VLOOKUP command
You have list of valid SKU#, you are working with, and you need to check if all records in the received Excel table contain valid SKU# values.
VLOOKUP command is an ideal solution for this case.
xlCompare uses same procedure for selecting Primary Key columns for the worksheet comparison and columns for the VLOOKUP function.
Use a key marker in the heading of the every column on the worksheet:
Click on the Marker to select this column for the VLOOKUP command
xlCompare highlights marker to reflect it's key state:
In addition to marker, xlCompare highlights data cells in the Primary Key column with color.
How to clear the marker state?
Second click on the marker clears it's state. Marker works like a switch.
Show I use Heading Rows with VLOOKUP command?
This is optional, but better to select heading rows to exclude heading area from the comparison.
This should make comparison results more accurate.
VLOOKUP gives you values that are present and not present in the FILE1.
But how to find values that are present in the vocabulary (FILE1) and not present in the data file?
Switch FILE1 and FILE2, select same columns and apply VLOOKUP once again.
All you need to do is to switch vocabulary and data. This is very easy method to get the results.

How to pull data into other CSV file

How to export comparison report into CSV file and save on disk?
Visually see the differences in CSV files is a good option, but how to send highlighted mismatching records to colleague by e-mail?
Use Copy button in the results panel.
Copy button copies highlighted table you have in the results panel into clipboard. After you have this data in your clipboard you can paste it into:
  1. Excel file
  2. Word document
  3. E-mail in the HTML format
  4. Notepad, etc.
Copy to clipboard is a universal method to export your data.
How to see matching and mismatching data in the comparison report?
Difference report brings you all cells in your CSV files. How to separate mismatching data to pull it into other file?
Click on the Legend entries for this.
Legend includes following items:
  1. No filter (default)
  2. Added Rows
  3. Deleted Rows
  4. Equal Rows
  5. Changed Rows
  6. Duplicate Rows
What is the difference between Equal, Changed and Duplicate rows?
Equal - completely equal rows in two CSV files. All cells are equal.
Changed - row contains at least one updated cell, that contains different value in FILE1 and FILE2.
Duplicate - combination of equal and changed rows - this is set of duplicate rows in two CSV files.

Compare two CSV Files for diffs using desktop tool

xlCompare is the best performing CSV diff tool that compares two CSV files for differences and presents you with a color-coded comparison report. Filters updated and equal records, gets the mismatching records, finds and extracts duplicate rows. xlCompare is your reliable partner if you are using CSV file in your business.
Compare CSV files in Excel
(Difference Report for two CSV files)

What are the benefits of choosing xlCompare to compare CSV files

xlCompare is a good choice if you need to compare CSV files on the daily basis. Let's look into the advantages you are getting if you choose xlCompare as you diff tool for CSV files


xlCompare is very easy to use and has intuitive interface, build in the close interaction with our customers. You don't need to spend your time learning the tool. Just install and use. In case of any questions our technical stuff will be happy to provide you with online demo of the product.


We don't give you a CSV comparison tool, we are saving your working time and increasing productivity. This is primary aspect of xlCompare.
In the modern world we are greatly overloaded, so working time is a critical resource.
xlCompare works on thousands of computers around the world and is chosen by leading companies.

You should not be expert in Excel to use this tool

xlCompare is a tool for all common Excel users. If you are an Excel expert or advanced user, probably you don't need a diff tool for Excel files at all. You can do everything yourself. But xlCompare is an option for common Excel users that are not familiar with Conditional Formatting, VLOOKUP function, Visual Basic for Automation programming language and so on.


Your files are not uploaded to the web. They are compared directly on your computer.

Compare files by Key

Database tables are often stored in the CSV files and Excel worksheets. Records that were exported from the database usually saved and transmitted as CSV.
xlCompare allows you to define primary key columns and heading rows in your tables and compare them as structured data, not like a usual spreadsheet model with formulas and calculations.

Lifetime License = No Future Payments

Lifetime license is an important advantage. You are getting a software that will work for you forever. xlCompare is not a subscription, so there will be no future payments.
Your license gives you ability to upgrade the software to all future versions of the software for free.
xlCompare makes complex things simple!

How to find differences in two CSV files with xlCompare

xlCompare is a easy way to find differences in two CSV files and highlight them with color. Just in a few clicks you will have your job done. And this is extremely simple.

Open your CSV files in xlCompare application

How to open two CSV files in xlCompare? Just drop them from the Windows explorer into the xlCompare window. The software will open them for you.
CSV file opened in xlCompare

Setup Primary Keys

Once you have your files opened, you need to make sure that Primary Keys are configured properly. This is highly important option to get the accurate results.
Each Primary Key column is marked with Key icon in the heading and highlighted with color.
If you think that you need another selection for your table, than the default one - do the right click on the column heading and set or unset the Key flag.
If you mark your column as Standard column - it will not be considered as Key.
Setup Primary Key in CSV file

Get the Results

Use Compare Sheets command on the Ribbon.
Compare Sheets command
It brings you Comparison Wizard window that contains summary of the data to be compared. After your Primary Keys are selected, just close it by pressing the Compare button and proceed to Comparison Report.
Comparison Wizard window

Comparison Report: xlCompare in the Action

xlCompare provides you with a comprehensive color-coded comparison report. All the differences found between two CSV files are highlighted with color. You will easily identify them among other cells.
Difference report for two CSV files

Changed cell value

Two changed cells are highlighted with Orange fill color.
For the numeric values xlCompare adds tendency icon that indicates increase or decrease of the value.
All identical rows with equal or changed cells are aligned on the worksheets one versus one.
Changed cells

Added and Deleted rows

All rows that are not identified in the other worksheet are highlighted with green color in the left file and with a red color in the right file.
Unique Rows (this term is used for added and deleted rows) doesn't have a corresponding row, so xlCompare inserts empty space into the corresponding worksheet to keep the alignment for the matching rows.
Unique Rows

Detailed information on the changes

Move your mouse over the orange cell and xlCompare will give you detailed information about what was changed in this cell in the Tooltip window.
This is easy and convenient way to get the details of the comparison.
Tooltip window with detailed information

Filter records in CSV files with xlCompare

xlCompare gives you several options on how to quickly filter your data in the worksheet. All of there commands are present on the Home tab of the Ribbon.
Filtering commands

All cells

This is the default selection. No filtering is applied, all cells on the worksheets are visible.

Matching Rows

xlCompare displays only rows with identical cells.
Matching rows in CSV files

Updated Rows

xlCompare display only rows that contains at least one updated cell. These rows have orange background in the heading.
Updated rows in CSV files

Unique Rows

This filter shows mismatched rows on two worksheets. So, if you apply this command xlCompare shows you only green and red rows in the compared CSV files. This is usually called - difference between the CSV files.
Mismatching rows in CSV files

Compare only specific segments of data in CSV files

xlCompare supports auto filter feature that is present in Excel application. If your CSV file is opened in xlCompare, it is automatically formatted as table and xlCompare applies auto filter to this table.
So, you can filter your data in the comparison report by specific data segments.
For example, if you need to compare sales made by your partners in specific marketing segments in USA, just select appropriate filters like on the image below.
xlCompare will show you records that belongs to this segment only.
Compare segments of data in two CSV files

Highlight differences in CSV files

How to highlight changed cells permanently in the file? Apply Mark Changes with Color command on the Ribbon.
It applies color formatting to every changed cell and every unique row.
Please note, that CSV file doesn't allow to keep the formatting options, so you need to save it as XLSX file by clicking on the Save As button.
Highlight changed cells in two CSV files

Extract data from the CSV file into Excel workbook

You've filtered your data by specific criteria. How to get these records including color formatting to be saved in the other file?
Use Save | Only Visible Rows command from the right click menu on the worksheet.
xlCompare will save visible data in the XLSX file on disk. This is easy way to export block of the worksheet and send it by email to your colleague.
Save visible rows in CSV file

Get Rid of Mismatching Rows in CSV file

How to clean your CSV file from the redundant rows, that are not present in the worksheet.
First you need to compare your CSV files for differences in xlCompare.
Apply Unique Rows filter to get the mismatching rows on your screen.
Select all the rows on one side and apply the Delete command from the right click menu.
xlCompare will remove rows from the worksheet.
Now your sheet is clean from the mismatching rows.
Save visible rows in CSV file

Merge(combine) two CSV files into one

xlCompare is a tool that gives you easy method to populate one CSV file with records from the other file.
Look into Merge tab on the ribbon
Set of the commands allows to copy data from one worksheet to another are located on this atb.
Merge commands
If you need to add all the mismatching rows from the left file into the right one - apply Insert Rows From Left command
All the green rows are moved into the right file in one click. Easy and convenient.
Similar command Update Cells from Left copies all the updated cells from the left file into the right one. You are getting your CSV file updated just in one click.
Merged cells in two CSV files

Compare three CSV files for diffs and matches

What to do if you have 3 CSV files you need compare at once. How to find rows that were updated in all CSV files. Or how to extract matching rows - rows that are present in all 3 lists of data.
Apply the 3-File option on the Home tab on the Ribbon.
xlCompare gives you additional panel for the third file. Just open your third file in this panel and get the result.
At no extra efforts you are getting results for such complex task.
In this mode xlCompare also allows you to filter data by specific criteria, filter changed and mismatching records, save visible portion of data on the other worksheet and so on.
Three file comparison for the CSV files is an important benefit that is present in the xlCompare.
Compare three CSV files for differences

CUSTOMER FEEDBACK: Very nice software

Very nice your software, the 3 ways blowed my mind out, I did a 2h job in 10 minutes (I looked 5 sec at my screen without moving because I was so surprised).
Olivier Regout

CONCLUSION: Choosing best CSV diff tool

So, which CSV diff tool is the best? How to make a decision on choosing best diff tool for CSV files.
Benefits of the xlCompare are already discussed above, there is no sense to repeat. But we would like to give you a short list of the proc and cons of the software.


xlCompare is a easy to use application that perfectly compares and merges CSV files. This tool is a real timesaver in many cases. Armed with xlCompare you can do complex tasks in a seconds.


Possible xlCompare has one minus - this tool is not free. You can use it during evaluation period, but after it expires you need to order a license.

Why xlCompare is an ultimate tool

xlCompare can be used in various cases that requires spreadsheet comparison. Following advantages makes this tool ultimate utility for CSV file comparison nd merging:

 Easy to use

Application has very clear and native interface, that is very similar to Microsoft Excel.


xlCompare makes you efficient in your daily work with Excel. This saves you a lot of efforts and working time.

 Clear results

You are getting clear and easy to understand comparison results. You can see examples on the screenshots above.

 Reasonable price

Actual price of xlCompare is amount of time spent to spreadsheet comparison multiplied by your hourly rate. So, the application has reasonable price in comparison with other tools on the market.

 Lifetime license

xlCompare is sold as a lifetime license. You don't need to pay more for this tool. License includes upgrades to all future versions of the xlCompare and support.
Now we have version 11 on the website. If you order it now, you will be able to upgrade it to xlCompare 12, xlCompare 15 and so on.
You never lose your license.

I have a question about xlCompare

Please, describe your question or inquery in the form below. We will be happy to respond you!


Get more information about comparing Excel spreadsheets and CSV files for differences. Alternatives to xlCompare and other useful information.


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