About

Pasting tabular data into plain-text environments (Markdown files, terminal logs, code comments, Slack messages, emails without HTML) destroys alignment. Columns collapse. Readability drops to near zero. Manually spacing columns with whitespace breaks the moment a single cell changes width. This converter parses raw CSV input using an RFC 4180-compliant state machine and renders it as a Unicode box-drawing table with precise column-width calculation. It handles quoted fields containing embedded commas, escaped double-quotes (""), and mixed line endings. Three border sets are available: Light (U+2500 block), Heavy (U+2501 block), and Double (U+2550 block). Column alignment is auto-detected - numeric data aligns right, text aligns left - but can be overridden manually.

The delimiter is auto-detected via frequency analysis across the first 10 rows, supporting comma, semicolon, tab, and pipe characters. Note: this tool assumes well-formed CSV. Malformed input (unmatched quotes, binary data) will produce unpredictable output. For CSVs exceeding 10,000 rows, only the first 50 rows are previewed, though the full output is generated for download. Pro tip: when pasting into monospaced environments, verify your font renders all box-drawing characters at uniform width - some fonts break alignment on double-line characters.

Formulas

Column width calculation determines the visual width of each column in the output table. For each column j, the rendered width W_j is computed as:

W_j = max(len(cell_i,j)) + 2 ⋅ p

where cell_i,j is the content of row i at column j, len returns the character count, and p is the horizontal padding (default 1 space per side). The max is taken across all rows i ∈ [0, n] including the header row.

Delimiter auto-detection uses frequency analysis. For each candidate delimiter d ∈ {, ; \t |}, the tool counts occurrences per line across the first 10 rows and computes the variance σ² of those counts:

σ²_d = 1n n∑i=1 (c_i − c)²

where c_i is the count of delimiter d in row i, and c is the mean count. The delimiter with the lowest non-zero variance and highest mean count is selected. A consistent delimiter produces zero variance across uniform rows.

Reference Data

Character	Unicode	Name	Used In
─	U+2500	Light Horizontal	Light borders
│	U+2502	Light Vertical	Light borders
┌	U+250C	Light Down and Right	Top-left corner
┐	U+2510	Light Down and Left	Top-right corner
└	U+2514	Light Up and Right	Bottom-left corner
┘	U+2518	Light Up and Left	Bottom-right corner
├	U+251C	Light Vertical and Right	Left T-junction
┤	U+2524	Light Vertical and Left	Right T-junction
┬	U+252C	Light Down and Horizontal	Top T-junction
┴	U+2534	Light Up and Horizontal	Bottom T-junction
┼	U+253C	Light Vertical and Horizontal	Cross junction
━	U+2501	Heavy Horizontal	Heavy borders
┃	U+2503	Heavy Vertical	Heavy borders
┏	U+250F	Heavy Down and Right	Heavy top-left
┓	U+2513	Heavy Down and Left	Heavy top-right
┗	U+2517	Heavy Up and Right	Heavy bottom-left
┛	U+251B	Heavy Up and Left	Heavy bottom-right
╋	U+254B	Heavy Vertical and Horizontal	Heavy cross
═	U+2550	Double Horizontal	Double borders
║	U+2551	Double Vertical	Double borders
╔	U+2554	Double Down and Right	Double top-left
╗	U+2557	Double Down and Left	Double top-right
╚	U+255A	Double Up and Right	Double bottom-left
╝	U+255D	Double Up and Left	Double bottom-right
╬	U+256C	Double Vertical and Horizontal	Double cross
╠	U+2560	Double Vertical and Right	Double left T
╣	U+2563	Double Vertical and Left	Double right T
╦	U+2566	Double Down and Horizontal	Double top T
╩	U+2569	Double Up and Horizontal	Double bottom T

Frequently Asked Questions

The parser implements RFC 4180 rules. Any field wrapped in double quotes is treated as a single value regardless of embedded commas, newlines (CRLF or LF), or other special characters. To include a literal double-quote inside a quoted field, it must be escaped as two consecutive double-quotes (""). For example, the CSV value ""Hello, World"" ""she said"""" produces the cell content: Hello, World "she said".

All characters come from the Unicode Box Drawing block (U+2500 to U+257F), which has been part of Unicode since version 1.1 (1993). Virtually all modern monospaced fonts support them. However, some proportional fonts and certain terminal emulators may render them at inconsistent widths. Always verify output in a monospaced font such as Consolas, Menlo, or Fira Code. The Double style (═║╔) has the highest risk of misalignment in non-standard fonts.

The converter normalizes all rows to the maximum column count found in the dataset. Shorter rows are padded with empty cells on the right. This means a CSV with rows of 3, 5, and 4 fields will produce a table with 5 columns, where missing cells appear as blank spaces. No data is discarded.

The tool scans non-header cells in each column. If more than 60% of non-empty values match a numeric pattern (integers, decimals, negative numbers, percentages, or currency values), the column is right-aligned. Otherwise, it defaults to left-aligned. You can override this per-column or globally via the alignment setting. Center alignment is available but never auto-selected.

File uploads are capped at 5 MB. Pasted or typed input has no hard limit, but CSVs exceeding 10,000 rows will only preview the first 50 rows in the output panel for performance. The full table is still generated when you click Download or Copy. For datasets above 50,000 rows, expect processing times of 2-5 seconds depending on column count and content length.

Yes. The auto-detect algorithm analyzes the first 10 lines for comma, semicolon, tab, and pipe characters. It selects the delimiter with the most consistent per-line frequency. You can also manually override the delimiter via the dropdown. For tab-separated data pasted from spreadsheets, the tool typically detects tabs correctly within one line of input.

By default, the tool trims leading and trailing whitespace from unquoted fields, following common CSV conventions. Quoted fields preserve all internal whitespace exactly as written. If you need to preserve whitespace in unquoted fields, disable the "Trim whitespace" option in settings. Padding spaces added for column alignment are separate from cell content and do not affect copy/download output integrity.