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Files
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Sheets
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Method
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Match
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Rules
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Columns
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Download
Step 1 of 7 · 🔒 local processing

Merge Excel & CSV files

Choose two or more files, or one Excel workbook with multiple sheets. You can add more files later.
🔒 Local by defaultNormal jobs are processed entirely on your device. Spreadsheet contents are not uploaded.
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Drop spreadsheet files here
or click to browse · XLSX, XLS & CSV
File size limits

Up to 1 million cells in total across every file you add — roughly 100,000 rows of 10 columns, or about 8 MB of spreadsheet. Also capped at 50 files and 50 MB. Cloud processing is not connected yet; files that exceed local limits are stopped and never uploaded.

Step 2 of 7
Which sheets should we merge?
Choose at least two sheets.
Select the sheets you want to include. A checkmark means selected.
Excel or CSV · stay on this step
Step 3 of 7
Choose how to combine the rows
Match columns is the default workflow. Stack Rows skips matching when you only need to append similar lists.
Merge type
Step 4 of 7
Choose your match columns
Required for joins. Choose the column in every sheet that identifies the same record. Nothing is preselected for you.
Match column for each sheet

Choose the column that identifies the same record in each sheet, such as email or Customer ID. Header names can differ. Blank values never match.

Next stepChoose a match column for every sheet to continue.
Step 5 of 7
Choose your matching rules
These rules decide what counts as the same value. They affect matching only — your exported values are never changed.
Step 6 of 7
Choose output columns
All columns are selected. Remove any you do not need, or change their order.
Available columns
Output order — 0
Step 7 of 7 · processed locally
Your merged workbook
Processing…
Merging your files…
Your spreadsheet data is staying on this device.

How to merge Excel files by a common column

Use a join when separate spreadsheets contain different information about the same records. For example, Customers.xlsx may contain names and emails while Orders.xlsx contains purchases. If both files contain a customer ID, email address or another shared identifier, MergeStudio can match those rows and combine selected columns into one workbook.

  1. Choose two or more Excel or CSV files, or select several tabs from one workbook.
  2. Select the worksheet sources you want to combine.
  3. Choose Matches Only, Master + Enrich, Keep Everything or Stack Rows.
  4. For joins, actively choose one or more matching fields.
  5. Review the matching rules and live match impact.
  6. Select and reorder the output columns.
  7. Merge, preview and download the result.

Inner join, left join, full outer join or stack?

Matches Only · inner join

Keep only records whose matching key appears across every selected source.

Master + Enrich · left join

Keep every row from one primary spreadsheet and add data from other files when a match exists.

Keep Everything · full outer join

Keep matched and unmatched records from all selected sources.

Use it as a VLOOKUP or XLOOKUP alternative

For exported files, a visual join can be simpler than adding lookup formulas one returned column at a time. MergeStudio lets you select several sources, map different key-column names, choose the fields to return and create a new merged workbook. If you need a live formula that recalculates when source cells change, Excel's VLOOKUP or XLOOKUP is still the better fit.

Private browser processing

Normal jobs are read and processed locally in the browser. Parsing and merging run in a Web Worker, and MergeStudio applies memory safeguards before and during large jobs. Files that exceed current local limits are stopped rather than silently uploaded.

How MergeStudio worksMerge 3, 4, 5+ Excel filesMerge Excel by common columnMerge CSV files by columnVLOOKUP alternativeJoin vs. stackMerge PDF files