About

Delimiter mismatches corrupt data pipelines. A misplaced comma in a CSV export fed into a line-based processor (grep, awk, log parsers) produces silent failures - rows merge, fields shift, and downstream analysis becomes unreliable. This tool performs deterministic string splitting: it takes an input string S, applies split(d) where d is the chosen delimiter, and joins the resulting array with \n (LF, Unicode U+000A). It handles edge cases - trailing delimiters, consecutive delimiters producing empty tokens, and mixed whitespace - through optional trim and empty-line filtering. The tool is bidirectional: it also converts newline-separated values back to comma-separated format for reassembly.

Limitation: this tool operates on plain text. It does not parse quoted CSV fields per RFC 4180. If your data contains delimiters inside quoted strings (e.g., "Smith, John"), those will be incorrectly split. For RFC-compliant CSV parsing, use a dedicated CSV library. Pro tip: when pasting from spreadsheets, cells are typically tab-separated - select the Tab delimiter for accurate conversion.

Formulas

The conversion applies a deterministic split-and-rejoin operation on the input string:

output = join(split(S, d), "\n")

Where S is the input string, d is the delimiter character (comma by default), and the result tokens are joined with newline characters. When optional trimming is enabled, each token t_i undergoes whitespace removal:

t_i = trim(t_i) for all i ∈ [0, n)

When empty-line filtering is active, the output excludes tokens where the length equals zero after trimming:

output = filter(tokens, t_i → |t_i| > 0)

The reverse operation (newline to comma) simply swaps d and "\n" in the formula. Token count n equals the output line count, providing real-time statistics.

Reference Data

Delimiter	Symbol	Unicode	Common Use Case	Risk if Mishandled
Comma	,	U+002C	CSV files, inline lists	Field shifting in data imports
Semicolon	;	U+003B	European CSV (locale-dependent)	Misread as comma CSV
Pipe	\|	U+007C	Database exports, log files	Confused with OR operator
Tab	\t	U+0009	TSV files, spreadsheet paste	Invisible - hard to debug
Colon	:	U+003A	Key-value pairs, /etc/passwd	Breaks time/path parsing
Space	␣	U+0020	Word splitting, CLI arguments	Breaks on multi-word values
Newline (LF)	\n	U+000A	Unix line endings, log lines	Missing on Windows (needs CRLF)
Newline (CRLF)	\r\n	U+000D+U+000A	Windows text files, HTTP headers	Double line breaks on Unix
Tilde	~	U+007E	Legacy mainframe data	Rare - unexpected in modern tools
Caret	^	U+005E	Custom delimited exports	Conflicts with regex anchors
Hash	#	U+0023	Comment-delimited config files	Stripped by comment parsers
Ampersand	&	U+0026	URL query parameters	HTML entity conflicts
Slash	/	U+002F	File paths, date formats	Breaks path parsing
Backslash	\	U+005C	Windows paths, escape sequences	Unintended escaping
Double Quote	"	U+0022	RFC 4180 CSV field wrapping	Unclosed quotes corrupt entire file

Frequently Asked Questions

Consecutive delimiters produce empty tokens between them. With the input "apple,,banana" and comma delimiter, the raw output is three lines: "apple", an empty line, and "banana". Enable the "Remove empty lines" option to filter out these empty tokens automatically. This matches the behavior of most programming language split() functions.

No. RFC 4180 allows commas inside double-quoted fields (e.g., "Smith, John" should be one token). This tool performs naive splitting - it will split on every delimiter occurrence regardless of quoting. For data containing delimiters within quoted fields, preprocess with a proper CSV parser first, then use this tool on clean single-value-per-field data.

When converting newlines to commas (reverse mode), the tool normalizes all line endings first - it replaces both \r\n (CRLF, Windows) and \r (old Mac) with \n (LF, Unix) before splitting. The output always uses LF (U+000A). If your target system requires CRLF, paste the output into a Windows text editor which will auto-convert on save.

Yes. The custom delimiter field accepts multi-character strings. For example, entering " | " (pipe with spaces) as the delimiter will split only on that exact three-character sequence, not on pipes or spaces individually. This is useful for data exported with padded delimiters.

Spreadsheet applications (Excel, Google Sheets) copy cell data as tab-separated values, not comma-separated. Switch the delimiter to "Tab" for correct conversion. You can verify by pasting into a plain text editor first - tabs appear as whitespace gaps wider than regular spaces.

The tool processes text in-browser with no server upload. Practical limits depend on your device's memory. Strings up to approximately 5 MB (roughly 5 million characters) convert instantly on modern hardware. For very large files (50 MB+), consider using command-line tools like tr or sed which stream data without loading it entirely into memory.