Merge Two CSV or Excel Files (VLOOKUP)

Add columns from a lookup file to your main file wherever a key matches, and see exactly which rows did not match.

Processed in your browser. Files never leave your device.

Main file (its rows are kept)

Lookup file (columns come from here)

Match main column with lookup column Keep If a key repeats in the lookup file

Columns to bring from the lookup file

Add both files to choose columns.

Ignore spaces around keys Ignore upper/lower case in keys Match 1001 with 1001.0 (codes like 007 stay distinct)

How it works

Paste or upload your main file and the lookup file (CSV, TSV, or Excel).
Pick the key column in each file. Structura suggests one when both files share a column name.
Tick the lookup columns you want to add and choose how to handle unmatched and repeated keys.
Click Merge, review the match counts, and download the merged file or an Excel report.

VLOOKUP between two files, without the formulas

Combining two exports is one of the most common spreadsheet chores: add stock levels to a product list, add the account manager to a list of invoices, add order totals to a customer list. In Excel that means a VLOOKUP or XLOOKUP per column, copied down thousands of rows, and #N/A errors that hide whether a key is missing or just formatted differently.

Here you pick the key once and every chosen column comes across in one step. The summary tells you how many rows matched, which main rows found nothing, which lookup rows were never used, and which keys appear more than once in the lookup file.

Why VLOOKUP misses matches, and what this does about it

Spaces: "1002 " and "1002" match when spaces are ignored
Numbers stored differently: 1001 and 1001.0 match, while codes with leading zeros such as 007 are not confused with 7
Upper and lower case: AB-9 matches ab-9
Repeated keys: VLOOKUP silently takes the first one; here you see them listed and can choose to get every match

Join types

All main rows works like VLOOKUP: every main row once, blanks where nothing matched (a left join)
Only rows that match drops main rows without a match (an inner join)
All rows from both files also appends lookup rows that matched nothing (a full outer join)

Free use covers files up to 5 MB and 20,000 rows each; Structura Pro raises that to 25 MB and 100,000 rows and keeps unlimited saved setups.

Popular uses: VLOOKUP between two Excel files

FAQ

Does my data get uploaded or stored?

No. Processing runs entirely in your browser. Structura does not upload your files for processing and does not keep file contents on a server. Closing the tab clears the in-memory copy.

Is processing private / local-only?

Yes for the tool’s job. Your files stay on the device. Optional Cloudflare Web Analytics may record page views and anonymous events such as tool runs and downloads, never file contents or file names.

How do I merge two Excel files based on one column?

Upload both files, choose the shared column (for example SKU or email) in each, tick the columns to bring over, and click Merge. Download the result as CSV or Excel.

What happens when a key is in the main file but not the lookup file?

With All main rows, the row is kept and the new columns are blank. Those rows are also counted and listed in the Unmatched rows download.

Can the key columns have different names?

Yes. Pick the key column separately for each file, such as sku in one and Product Code in the other.

What if the lookup file has the same key twice?

You choose: use the first match, as VLOOKUP does, or add a row for every match. Repeated keys are always listed so you can fix the source.

Do I need an account?

No. All Structura tools are free to use without signup.

Need a data tool we don’t have yet?

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