CSV Viewer: Preview Files & Delimiters
Preview the header and first records of a CSV using quoted-field parsing.
Choose a CSV to inspect its headers and first records.
A clear result starts here
Run the tool to see your output here.
Try the example to explore how it works.What to know about this tool
Shows up to 21 parsed rows including the header. Very large input still has to fit in browser memory. Up to 10 MB, 50,000 rows and 200 columns; rectangular CSV with unique nonblank headers required. CSV output has a conservative 20 MB cap.
Instructions and examples
From input to output
- Choose a CSV, TSV or TXT file, or paste its contents.
- Leave Input delimiter blank for detection, or enter the actual separator.
- Select Preview CSV and inspect the headers, row count and first 20 data rows.
Settings and result behavior
- The result table shows up to 20 rows; the source preview is also a sample, not the whole dataset.
- Values stay strings. The preview does not evaluate formulas, infer dates or repair records.
A worked example
- Input
id,name,note 001,Ada,"hello, world" 002,Lin,"two lines"
- Settings
- Input delimiter blank; comma detected.
- Expected result
2 data rows and 3 columns. The comma and line break inside quoted notes remain part of their cells.
Supported input and limits
Choose a UTF-8 CSV, TSV or TXT file, or open “Paste CSV instead”. Use comma, semicolon, tab or pipe separators. A header row with unique nonblank names and the same field count on every row is required. Download TXT saves the text preview, not the full source CSV.
Shows up to 21 parsed rows including the header. Very large input still has to fit in browser memory. Up to 10 MB, 50,000 rows and 200 columns; rectangular CSV with unique nonblank headers required. CSV output has a conservative 20 MB cap.
If the result is unexpected
- If columns appear wrong, enter the actual delimiter for that input and check quoted values.
- For rectangular-record errors, correct missing/extra fields in the source. Empty internal records are not silently repaired.
Check before using the result
Check headers, quoted newlines and leading-zero IDs. A clean sample does not prove that every record is suitable for your intended import.
Report a problem with this tool. Include a nonsensitive example and your browser details.
Practical guides
- Compare Two CSV Exports Using a Unique Key
Match CSV records by a stable identifier and distinguish added, removed and changed rows from simple row-order differences.
- Clean a CSV While Preserving Leading-zero Identifiers
Trim cells and headers, remove exact duplicate rows and inspect identifiers before importing a cleaned CSV into a spreadsheet.