CSV エディタ

CSV Editor is a browser-based spreadsheet-style editor for opening, editing, sorting, resizing, and exporting CSV files without sending the file to a server. It supports comma, semicolon, tab, and pipe delimiters, preserves quoted values, and keeps data local to the browser.

Upload a CSV file, paste CSV text, or load a sample dataset. Edit cells inline, add or delete rows and columns, sort by clicking a column header, drag column borders to resize, and download the edited CSV when finished. Toggle Header when the first row should be treated as column labels.

The table uses virtualization for the default non-wrapped view so large CSV files can be inspected without rendering every row at once. Files above 100,000 data rows are capped for browser safety, and very large datasets may skip autosave with a warning so users can download a copy instead of relying on browser storage.

Parsing and export are handled with Papa Parse. Quoted commas, escaped quotes, quoted newlines, empty cells, Unicode text, duplicate column names, missing trailing values, and extra trailing values are normalized into a consistent editable table and round-trip through export.

CSV content is processed locally in the browser. Small and medium sessions autosave to IndexedDB after changes, while display preferences such as wrap text and auto-fit stay in localStorage. Clear removes the current editor session from local browser storage.

Browser memory, storage quota, and main-thread parsing limits still apply. Extremely wide files, very long cell values, or very large row counts can be slower than a desktop spreadsheet or database tool. Split oversized CSV files before editing when possible.