CSV Editor & Converter — Step-by-Step Guide
Learn how to use CSV Editor & Converter: step-by-step instructions, settings, export options, privacy, limits and troubleshooting.
Open CSV Editor & ConverterStep-by-step instructions
- Choose a file or paste CSV/JSON and load it, or start a new table.
- For CSV choose the delimiter and text encoding; for XLSX select a worksheet.
- Edit the header and cells, add rows or columns, and optionally apply filtering, text sorting or deduplication.
- Choose CSV, JSON or XLSX, then export and download.
Exact values and supported formats
Every cell is edited as text. CSV supports quoted fields, embedded line breaks, doubled quotes, and comma, semicolon, tab or pipe delimiters. Text import supports UTF-8, UTF-16 LE/BE and Windows-1252. CSV export is UTF-8 with a byte-order mark.
JSON accepts an array of row arrays or an array of flat objects. Numeric tokens are retained exactly, booleans become text and null becomes an empty cell. Object keys become headers; duplicate keys and nested cell values are rejected. JSON output is always row arrays of strings.
XLSX imports one selected worksheet from a workbook of up to 50 sheets. Shared strings and inline strings are supported. Numeric cells keep their stored spelling; dates may appear as Excel serial numbers. Formatting, merged-cell structure, charts and objects are not retained. XLS, XLSM and encrypted workbooks are unsupported.
Filtering, formulas and export safety
The first row is the header and is excluded from sorting and deduplication. Sorting compares text, so 10 sorts before 2. Filtering matches any cell without case sensitivity. Applying a filter removes non-matching rows from the current editor; reload the source to restore them.
Formulas are never executed. Imported formulas appear as literal text beginning with =. XLSX writes all cells as inline strings. CSV prefixes formula-like values, including leading =, +, -, @ and leading whitespace before them, with an apostrophe. That safety prefix changes those CSV values; use JSON or XLSX for exact strings. No CSV mitigation controls how another application later rewrites a file.
Bounds and storage
Tables are limited to 2,000 rows including the header, 50 columns, 20,000 rectangular cells, 10,000 characters per cell and 500,000 characters total. The grid shows 50 rows at a time.
XLSX archives are limited to 256 entries, 8 MB per expanded member and 16 MB total. Suspicious compression ratios, encrypted entries, unsafe paths and DTD/entity XML declarations are rejected. Work is kept only in page memory.
Processing and privacy
Files and entered content are processed on your device in this browser tab. File contents and results are not uploaded to Helphonic or sent to analytics. The page still contacts Helphonic to load its tools, check access and confirm non-content usage information. Work is not saved to your account; download or copy results before leaving or reloading the page.
Access and current limits
Check the tool page for current access, remaining usage and per-operation limits. File count, per-file size, total size and page limits can depend on your access and can change. Device and processor safety limits still apply when usage is unlimited. A paid pass does not necessarily increase every processing limit.
One successful export counts as one operation. Previewing and editing do not use an operation. Daily allowances reset at 00:00 UTC. Downloads of an already-created result do not count again.
If an operation cannot finish
Use a current browser and smaller inputs if the tab runs out of memory. Some tools download a local processing library or model on first use, so an internet connection is needed even though your content stays on the device.
If the tool reports that access or limits changed, review the current policy and run it again. If usage confirmation is uncertain after an interrupted connection, a retry can count as another operation. Download completed work before reloading; this site does not keep a recovery copy.
Check the current limits
Allowances and per-operation limits can change. The CSV Editor & Converter page shows the policy that applies to you. Per-operation safety limits still apply when usage is unlimited. See access passes if a tool or extra usage requires paid access.
For site-wide information, read the privacy policy and security details.