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Lizely

CSV to Excel Converter

Turn a local CSV table into a downloadable .xlsx workbook without uploading the file or running spreadsheet formulas.

Privacy: your files never leave your device. All processing happens locally in your browser.

How to use

  1. 1.Paste CSV data or choose one local CSV file no larger than 500 KB.
  2. 2.Check quoted commas and line breaks, then select Convert to Excel.
  3. 3.Download the .xlsx workbook and open it once in the destination spreadsheet program.

About CSV to Excel Converter

CSV to Excel converts a comma-separated table into one downloadable .xlsx workbook without sending the CSV to a server. You can paste CSV text directly or choose a small local .csv file. The browser parses the rows, creates a workbook with one worksheet named CSV data, and gives you a normal Excel-format download. The source file is not overwritten, retained, or shared with Lizely. This is useful when a data export, report, contact list, or simple table arrives as CSV but the next person or application expects a workbook.

CSV has a precise quoting rule that matters for real data. A comma inside a quoted field is data, not a new column; doubled quotation marks represent one literal quotation mark; and a quoted field may contain a line break. This tool accepts CRLF, LF, and CR record endings and checks that every row has the same number of fields. It rejects an unclosed quote, a malformed field after a closing quote, or a ragged record instead of guessing which values belong in which columns. The first CSV row is written as the first worksheet row. The tool does not infer dates, identifiers, currencies, locale conventions, or a special business schema.

The workbook is intentionally a plain data export. Text values are passed to SheetJS as text cells, including strings beginning with =, +, -, or @, so the browser never evaluates them as spreadsheet formulas while creating the file. The tool does not run macros, external links, embedded scripts, formulas, or remote data connections. It does not promise that another spreadsheet application will apply the same display formatting, because CSV itself has no types, widths, colors, merged cells, charts, comments, validation rules, filters, or print layout. Keep the source CSV when those distinctions matter.

Clear limits protect the browser and make failure visible: CSV input is limited to 500 KB, with at most 10,000 data rows, 200 columns, and 200,000 cells. The browser stops with an error when a limit or CSV syntax rule is exceeded; it never quietly drops a row, trims a column, or writes a partial workbook. The output is an OOXML .xlsx ZIP package. A spreadsheet program may still warn about data types or choose its own regional formatting when opening the result, so verify a meaningful sample in the destination system before using it for a business import.

For a dependable conversion, start with the smallest relevant CSV, confirm that the header row and quoted fields look right in the preview text, create the workbook, then open the downloaded .xlsx once. Keep identifiers such as account numbers as CSV text if leading zeroes matter, and do not assume that a number-looking string will remain text after another application imports it. This tool does not merge files, repair corrupt CSV, infer column labels, validate personal data, generate formulas, or convert legacy spreadsheet formats. It provides one transparent local path from a well-formed CSV table to an Excel workbook.

Methodology & sources

Parse a bounded RFC-style CSV table locally; reject malformed or ragged records; dynamically load the locked SheetJS core only when creating an OOXML workbook; write visitor values as ordinary cells without formula execution.

Frequently asked questions

Does this upload my CSV?
No. Parsing and workbook creation happen in the current browser tab.
Can quoted commas and line breaks stay in one cell?
Yes. The parser supports standard quoted CSV fields and record endings.
Will text starting with an equals sign run as a formula?
No. The converter writes visitor text as a text cell and does not execute formulas.

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