CSV structure inspector

How to use this application

This CSV structure inspector gives a quick view of a small comma-separated table before you import it elsewhere. Paste the text, including its header row, and choose Inspect CSV. The result shows how many data rows and columns were parsed, how many rows exactly repeat an earlier row, and the number of empty and distinct nonempty values in each column. It reports structure; it does not change, repair or upload your data.

Start with Load example. The example has three data rows and three columns. Two rows contain the same name, team and note, so one row counts as a duplicate. One note is empty. The quoted note contains a comma, which stays inside that field rather than creating another column. Choose Clear to remove both the input and results. Editing the text clears the old result, so choose Inspect CSV again after a change. Repeated inspections replace the result instead of accumulating tables.

Use commas between fields and double quotes around fields that contain commas or line breaks. A double quote within a quoted field must be written twice. Both Unix line endings and Windows line endings are accepted, and the final record may end with a line break. A leading Unicode byte-order mark is ignored. Delimiters such as semicolons and tabs are not detected or converted. If your export uses another delimiter, choose a comma-separated export in the application that created it.

The first record is always the header. Every later record must contain the same number of fields. An unmatched quote, text after a closing quote or an uneven row produces an error instead of a partial summary. Blank lines inside a multi-column file therefore need the right number of separators; they are not silently discarded. Blank and repeated header names are reported while column positions remain separate. The inspector does not infer a schema or check whether values satisfy business rules.

For empty-cell counts, a cell containing only whitespace is empty. Distinct nonempty values use the original, case-sensitive text, and duplicate rows use every original field. Leading spaces and differences in capital letters can therefore make otherwise similar values distinct. The tool does not treat words such as NULL or NA as empty, convert dates or numbers, evaluate spreadsheet formulas or remove duplicates. A formula-like value is displayed as text rather than executed.

To keep processing modest, the input is limited to 1,000,000 characters, 5,000 data rows and 100 columns. A large or unusual export may need a dedicated desktop data tool. This summary is a preliminary check rather than a guarantee that another importer will accept the file. Compare the result with your source and the receiving program’s requirements.

All entries and calculations stay in the current page’s memory. There are no accounts, uploads, tracking, cookies or browser-storage writes. Clear removes the input, and reloading starts a fresh page. There is no saved history or cross-device sync. Browser extensions and device-level clipboard or session-restoration features are outside this tool’s control. JavaScript is required for the inspection, while these instructions remain readable in the main application page.