CSV Viewer & Validator

CSV to JSON Converter turns the rows of a delimited file into JSON, using the same parser as CSV Viewer (delimiter guessed from the first line — comma, semicolon or tab). If you mark the first row as a header, the output is an array of objects keyed by that row; without a header it is an array of arrays. Every value comes out as a string — 42, true and blank cells are all quoted text, with no type guessing. An empty header becomes column_1, column_2 and so on; a repeated header gets _2, _3 appended; the risky keys __proto__, constructor and prototype are renamed. A row shorter than the header fills the missing keys with empty strings; a row with extra cells has them dropped. Choose two-space pretty output or a compact one. Input is capped at 2 MB, 50,000 rows and 250,000 cells, and the file is read in the browser.

CSV Duplicate Row Remover deletes rows that repeat and keeps the first of each, leaving every other row in its original position — it never sorts. Two rows are duplicates when their parsed cells match across the whole row. Case-sensitive comparison is on by default; untick it to treat "Anna" and "anna" as the same. It compares parsed values, so a quoted "a" and a bare a match, but a cell with an extra leading or trailing space does not match one without — quoting and stray whitespace can keep near-identical rows apart. The first row is treated as a header by default: kept untouched and excluded from the comparison, unless you tick the box to include it as data. The delimiter is auto-detected from the first line or chosen manually, the output uses LF line endings, and a count of removed rows is shown. Unlike CSV Viewer it rewrites the file, and unlike CSV to JSON the result is still CSV. Limits: 2 MB, 50,000 rows, 250,000 cells.

Reorder the rows of a CSV by one column you choose, entirely in your browser. Paste your CSV, pick the delimiter (comma, semicolon, tab, or auto-detect), say whether the first row is a header, then read the columns and sort. You choose the sort type explicitly — text, number, or ISO date — because guessing is unreliable for IDs, zero-padded values and locale date formats. Text sorting is case-sensitive and deterministic; number sorting accepts standard numeric literals and rejects thousands separators, currency and integers beyond the JavaScript safe range; date sorting accepts only YYYY-MM-DD and ISO 8601 timestamps with a time zone. Empty cells and values that do not match the chosen type are always placed last, ascending or descending, and rows with an equal sort key keep their original order (stable sort). The header row stays in place. Quoted cells, embedded commas and embedded newlines are preserved through the shared RFC 4180 parser and serializer; malformed CSV is rejected rather than repaired. Nothing is uploaded or stored. This version sorts by a single column; it is not a spreadsheet, it does not remove or select columns, and it does not remove duplicate rows.

Choose which columns to keep in a CSV, drop the ones you do not need, and reorder the ones you keep — entirely in your browser. Paste the CSV, pick the delimiter (comma, semicolon, tab, or auto-detect), say whether the first row is a header, then read the columns. Every column starts selected; untick the ones to remove and use Move up / Move down to set the output order. Columns are identified by position, so duplicate header names such as two "name" columns are handled correctly, and empty or missing header cells are labelled as such rather than hidden. A data row that has more columns than the header is still exposed, never silently lost. Rows that are shorter than the selection get an empty value for the missing cell. The tool does not change row order and does not change any cell value: quoted cells, embedded delimiters and multi-line values are preserved through the shared RFC 4180 parser and serializer. Nothing is uploaded or stored. This is not a spreadsheet; for sorting rows use CSV Sorter, and for inspecting a file use CSV Viewer.