Join CSV/Excel Files (VLOOKUP Online)
VLOOKUP for whole files: bring columns from one table into another by a key.
1. Main table
The rows to keep and fill in — for example your orders or a list of students.
Or paste the table (from Excel, Google Sheets or a CSV)
2. Lookup table
Where the values come from — for example a customer list, a price list or a code list.
Or paste the table (from Excel, Google Sheets or a CSV)
3. How to combine them
4. Result
Reports
About the Join CSV/Excel Files (VLOOKUP Online)
Bring columns from one table into another by a shared key — customer names into a list of orders, prices into an order sheet, branch names into a payroll export — without writing a single VLOOKUP. Choose the key column (or several, such as first and last name), and every row of the main table gets the matching values from the lookup table, the way VLOOKUP or XLOOKUP fills one cell at a time.
You also get the joins a database offers — only matching rows, every row of the lookup table, every row of both, or the rows that have no match (to find what is missing). Keys can match ignoring spaces, upper and lower case, zeros in front (007 = 7) and how numbers are written (1,000 = 1000.00). Reports list the rows that found no partner and the keys that appear more than once, the classic reason a VLOOKUP gives an unexpected answer. A second mode recodes one column from a two-column mapping table — state codes to names, old product codes to new ones.
How to use it
- Add the main table (the rows you want to keep) and the lookup table (where the values come from): CSV, TSV, Excel, ODS or Numbers files, or tables pasted from a spreadsheet.
- Under Match rows where, pick the key column in each table; columns with the same name are suggested. Add more key columns if one is not enough.
- Choose what to keep — every main-table row (like VLOOKUP), only matches, every row, or the rows without a match — and which lookup columns to bring in.
- Tick the differences to ignore when comparing keys, and choose what happens when a key is in the lookup table more than once.
- Check the counts and the preview, then download the result as CSV, TSV or Excel, and the reports if you need them.
Examples
Orders: OrderID, CustomerID, Amount · Customers: CustomerID, Name, City
OrderID, CustomerID, Amount, Name, City — every order, with the name and city of its customer; orders whose customer is not in the list keep empty cells.
Main: the member list · Lookup: this month’s payments · Keep: main-table rows with no match
Only the members with no payment row.
Tick How numbers are written if membership numbers appear as 1001 in one file and 1,001 or 1001.0 in the other.
State column: MH, DL, ka · Mapping: MH → Maharashtra, DL → Delhi, KA → Karnataka
Maharashtra, Delhi, Karnataka (case ignored), and a list of any codes the mapping does not have.
Common uses
- Adding prices, names, categories or tax rates from a master list to transaction exports.
- Finding records that are in one system but not in another — customers without orders, invoices without payments.
- Combining two exports of the same records that each have different columns.
- Replacing codes with their meaning, or old codes with new ones, from a mapping table.
Which rows are kept
- Every main-table row (a left join): the VLOOKUP result for every row; rows without a match get the text you choose (empty, or for example #N/A, as XLOOKUP’s “if not found”).
- Only rows found in both tables (an inner join).
- Every lookup-table row (a right join) and every row of both tables (a full outer join): rows without a partner keep their own values and empty cells for the other table; the key columns are filled in from whichever table has them.
- Rows with no match in the other table (anti-joins): to find what is missing.
These are the joins of the relational model of data that databases use. A row whose key cells are all empty never matches.
Matching keys, and keys that repeat
Keys are compared exactly, after the clean-ups you tick: spaces at the start and end, upper and lower case, zeros in front of numbers (007 = 7) and how numbers are written (1,000 = 1000 = 1000.00, $1,000 or ₹ 1,000 = 1000; long numbers such as card or account numbers are compared digit by digit, never rounded). With several key columns, all of them must match.
When a key is in the lookup table more than once, VLOOKUP silently takes the first. Here you choose the first, the last, or every match — then the main-table row appears once for each match, as in a database join. The duplicate-key report lists every repeated key with its row numbers in both files (the header counts as row 1).
Limitations
- Each file up to 100 MB as CSV or 50 MB as a workbook, with at most 10 million cells: both tables are joined in your browser’s memory.
- Values are compared and copied as the text shown in the file; in an Excel download, columns that hold only numbers become numbers again.
- Keys must be equal after the clean-ups — similar spellings (Asha Rao and Aasha Rao) do not match.
- Up to three key columns.
Privacy
Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot.
Frequently asked questions
How is this different from VLOOKUP?
It does the same lookup for every row at once, on whole files, without formulas that break when rows move. It can also match on several columns, keep every match instead of the first, and list the rows that found no match.
Why do some rows not match although the values look the same?
Usually hidden differences: a space at the end, different capital letters, 007 in one file and 7 in the other, or 1,000 versus 1000.00. Tick the matching clean-ups under When comparing keys, ignore and the counts update at once.
Can I match on two columns, such as name and date of birth?
Yes. Select Add another key column and pick the second pair; rows match only when every key column matches.
How do I find the rows that are missing from the other file?
Choose Main-table rows with no match in the lookup table (or the other way round). The report buttons also download the unmatched rows with their row numbers.
Is my data uploaded?
No. Both files are read and joined in your browser; the results are created on your device.