CSV Editor & Converter

Edit tables, filter, sort and remove duplicates locally. Convert CSV, JSON and XLSX while preserving text, leading zeros and exact number spelling.

Unlimited Free Usage

The first row is the editable header. Cells stay as text; numeric spelling and leading zeros are retained. CSV prefixes formula-like cells with an apostrophe for safer spreadsheet opening. JSON/XLSX preserve exact strings. XLSX imports one chosen sheet, values and formula text only; dates remain stored values. Changes and applied filters are not automatically saved.

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File contents and entered text stay on this device. Only access checks and non-content usage metadata go to Helphonic.

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Current limits

per operation

Files
1
Per file
5 MB
Total size
5 MB
Table cells
20,000 maximum
Table rows
2,000 including header

Limits protect your device memory. Processing speed depends on your device.

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Limit comparison

How to increase limits

Compare the per-operation limits available after registration or with an active paid pass.

Free account

Registered user

Unlimited Free Usage

Files
1
Per file
5 MB
Total size
5 MB
Table cells
20,000 maximum
Table rows
2,000 including header
Create a free account
All access passes

Unlimited operations during active validity, subject to abuse safeguards.

Files
1
Per file
5 MB
Total size
5 MB
Table cells
20,000 maximum
Table rows
2,000 including header
View packages

The same limits may apply to every tier. Check before purchasing. Device safety limits still apply.

Frequently asked questions

Are files or entered contents uploaded?

No. Files, edits, signature strokes and resume details are processed on your device. Helphonic supplies the application and local libraries and exchanges only non-content access and usage metadata.

Is this tool free for guests and registered users?

This tool starts with unlimited free operations for guests, registered users and active paid users. Administrators may change allowances later. The current access policy is displayed on this page; device safety limits still apply.

Is my work saved automatically?

No. Keep the original files and download your result before leaving. Editing and previews do not consume an operation. A successful confirmed export counts as one operation if allowances are enabled.

What formats and limits should I check?

One optional 5 MB file; 2,000 rows, 50 columns, 20,000 cells and 500,000 characters; XLSX expanded size 16 MB.

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How to use

CSV Editor & Converter

Learn how to use CSV Editor & Converter: step-by-step instructions, settings, export options, privacy, limits and troubleshooting.

Step-by-step instructions

  1. Choose a file or paste CSV/JSON and load it, or start a new table.
  2. For CSV choose the delimiter and text encoding; for XLSX select a worksheet.
  3. Edit the header and cells, add rows or columns, and optionally apply filtering, text sorting or deduplication.
  4. 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.

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.

About this tool

Import CSV, JSON or XLSX, paste a table or start a new one. Edit cells, add rows and columns, filter, sort and deduplicate. Export UTF-8 CSV, JSON arrays of strings or an XLSX workbook containing text cells.

Read the full CSV Editor & Converter guide (opens in a new tab)