Inspect and clean a large CSV file
Load a CSV to see it as a table, confirm the delimiter, and catch ragged rows, stray whitespace, or quoting problems before you import it somewhere that will choke on them.
Open the tool, then paste the sample input below. Everything runs locally in your browser.
The problem
A CSV export will not import cleanly and you need to see why: maybe the delimiter is a semicolon, a row has the wrong number of columns, or there is a stray quote. Opening it as a table in the browser makes these issues visible without loading it into a database first.
Sample input
id;name;city
1;Ada; London
2;Ben;"New York"
3;Cleo;ParisExpected output
id | name | city
1 | Ada | London
2 | Ben | New York
3 | Cleo | ParisThe viewer detects the semicolon delimiter, trims the stray space before "London", and reads the quoted "New York" as one value.
How to do it
- Load or paste the CSV.
- Confirm the detected delimiter.
- Scan the table for ragged or misaligned rows.
- Trim whitespace and fix quoting issues.
- Copy the cleaned data for import.
Common mistakes
- Assuming a comma delimiter when the file uses semicolons or tabs.
- Stray whitespace around values that breaks key matching later.
- Unescaped quotes or commas inside a field.
- Rows with a different column count than the header.
- A byte-order mark or wrong encoding corrupting the first column name.
Related tools
Related guides
FAQ
How do I open a large CSV in the browser?
Load or paste the CSV into the viewer. It parses the file locally and shows it as a table so you can scan columns and rows without a database.
What if my CSV uses semicolons or tabs?
The viewer detects common delimiters such as comma, semicolon, and tab. Confirm the detected delimiter so the columns split correctly.
How do I find ragged rows?
Scan the table for rows whose column count differs from the header. Those rows usually have an unescaped delimiter or a missing value.
Can it handle quoted fields with commas?
Yes. A quoted field that contains the delimiter is read as a single value, so "New York" stays in one cell.
Is my CSV uploaded?
No. Parsing happens locally in your browser. The file is not sent to a server.
CSV parsing runs locally in your browser. Your file is not uploaded.
Inspect CSVs, compare data, clean lists and build SQL filters — grouped in one place.