Merge, deduplicate, compare and query spreadsheets.

31 tools that run inside this page. Below is the sample merge, drawn — press the button and your browser runs it here, the same way it will run yours.

Merge two filesExample · the sample files

sample-customers.csv and sample-orders.csv, matched on customer_id against cust_ref, keeping all 8 rows of the first file.

Sources

sample-customers.csv8 rows, 4 columns
sample-orders.csv8 rows, 4 columns

Match on

customer_id against cust_ref

Which rows to keep

All 8 rows from the first file, whether or not the second file has anything for them.

Result9 rows × 8 columns

5 matched
3 kept, nothing to join
1 extra from a repeat

customer_id	name	email	city	order_id	cust_ref	amount	status
00412	Priya Sample	priya@example.com	Pune	S-1003	00412	32.10	refunded
00413	Grace Example	grace@example.com	Bristol	S-1002	00413	89.50	paid
00415	Ada Fictional	ada@example.com	Nairobi	S-1004	00415	410.00	paid
00416	Linus Notreal	linus@example.com	Turku	S-1005	00416	55.25	pending
00417	Maria Demo	maria@example.com	Porto	S-1008	00417	240.00	paid
Second row for this key, added by a repeat: 00412	Priya Sample	priya@example.com	Pune	S-1001	00412	150.00	paid

The marked row is the second order for 00412 — the repeat the third chip counts. Six of the 9 rows are shown; the table scrolls sideways for the remaining columns.

Starts a real database engine in this tab — about 37 MB, downloaded once — and runs the merge above for real. Or open the full tool instead.

That was one of 31

All tools, with search

Combine and compare files 3

Two files that should be one, or should agree, or hold the same row twice.

Clean and fix a file 5

A file that opens wrong, or carries something that should not be in it.

Pick and order rows 6

Keep, order, count or sample the rows you need; the values stay as written.

Reshape columns 5

Change the shape of the table without changing a single value in it.

Convert between formats 11

The same table in the format the next program wants, nothing retyped.

Ask questions in SQL 1

For the job none of the forms above describes: write the query yourself.

SQL consoleRun SQL on a CSV file

Check it yourself

Open your browser's developer tools, select the Network tab, and use a tool with a real file. Every request goes to this domain and none carries a body — the content security policy sets connect-src 'self', so the browser blocks anything else. It is not a promise we are asking you to take on trust.

Or prove it the blunt way: turn off your Wi‑Fi — in a moment. Your browser is still storing the offline copy of every tool, a one-time download on the first visit, and this line will extend the invitation the instant the copy is in.

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