Preview a CSV File Before You Import It
Need to check whether you have the right export before bringing it into another app? The CSV Preview Tool opens a CSV or TSV file as a table and shows its first 25 data rows. Above the table, you can check the file name, total parsed data-row count, column count, and file size.
This is a quick way to inspect column names and sample values, or to catch an obviously wrong file before you move on. The preview is read-only: it does not change the source, and it does not claim to validate every row.
What You See in the Preview
The first non-empty record is used as the heading row. The rows beneath it are the data. The table displays up to the first 25 data rows, while the summary counts data rows from the complete parsed file. Completely blank lines are skipped when the file is parsed, so the displayed data-row count may differ from the number of physical lines in a text editor.
The column count reflects the widest parsed record. The tool detects a common separator—comma, tab, semicolon, or pipe—from the first non-empty line and understands quoted fields. If the file has an unfinished quoted field, it cannot be parsed for preview. A blank cell in the header remains blank in the table.
Use the Sample to Decide What to Do Next
Check that the headings look familiar, that values appear under the expected columns, and that the first records resemble the data you intended to open. A preview can reveal a wrong file, unexpected headings, or values that appear shifted. Because only 25 data rows are shown, it cannot confirm that every later record is correct or that all rows have a consistent structure.
To search, sort, or browse the complete table, open the CSV Table Viewer. To edit cells, use the CSV Spreadsheet Editor. To check the file structure, continue with the CSV Validator.
File Size and Browser Processing
CSV and TSV files up to 50 MB are accepted. Although the table shows only 25 data rows, the browser reads and parses the full file to calculate its total row count and column count. Large files may therefore take longer to prepare and use more memory. The file is processed in your browser and is not sent to a server by this tool.
Questions About CSV Previews
Does the preview show the whole CSV file?
No. It displays up to the first 25 data rows. The row and column totals are calculated from the full parsed file.
Does the preview use the first row as a header?
Yes. The first non-empty record becomes the headings. If your CSV has no header row, its first record will be treated as headings rather than displayed as data.
Does the CSV Preview Tool check every row for errors?
No. It provides a sample and file counts, but it does not validate every row structure. Use the CSV Validator for structural checks.
Why does a 25-row preview take time to load?
The browser parses the complete file to calculate total row and column counts, even though it displays only the first 25 data rows. The file size and your device affect how long this takes.
Can I edit the data from this preview?
No. The preview is read-only. To change cell values, open the CSV Spreadsheet Editor.
Are my CSV or TSV contents uploaded?
No. This tool reads and parses the selected file in your browser and does not send the file contents to a server.