Convert CSV, XLSX and ODS locally

CSV to a text workbook

Choose comma, semicolon, TAB or vertical bar. Every field remains text in its original position, including the first record, empty strings, leading zeros and large numeric spellings. No header, number, date, Boolean, null or formula is inferred. A separate fixed WebUT Audit sheet is generated. CSV quoting and original CSV syntax do not survive as syntax.

Inspect, then choose a sheet or table

The whole supported package and every sheet or table are checked before selection, including hidden and unselected content. Choose one ordinal, the complete finite extent or an exact A1 range, and explicitly acknowledge raw stored values, exclusions and any encoded hidden or filtered content. Conversion rereads the same Blob and verifies the complete source and catalogue binding before output.

CSV is UTF-8 with every field quoted and CRLF records, including the final record. Raw stored string, numeric and Boolean tokens are exported. Formulas and unsupported package content refuse the whole source. Displayed numbers, dates, currency, previous precision, styles, charts, fonts, native visibility and layout are not recovered. Missing slots, unvalued cells and empty strings become quoted empty fields with separate report counts.

Exact fields or explicit prefixing

Exact mode adds no prefix. Prefix mode changes a field by adding one apostrophe when its first character is =, +, -, @, TAB, CR or LF, including a matching raw numeric token. CSV quoting and this finite prefix policy do not guarantee receiving-spreadsheet safety. Other sheets, generated audit content and first/header rows are never silently skipped by name.

Complete output and original ownership

Outputs use fixed filenames: webut-result.xlsx, webut-result.ods, webut-selected-sheet.csv and webut-spreadsheet-report.json. The report contains bounded counts and profile findings, not source filenames or cell values. Each action has one original sixty-second window for a local read clipped to ten seconds, production, fresh-source reconstruction and complete Blob preparation. Accepted review persists after that processing window until edit, Cancel, Clear or workflow retirement. Each explicit download has a separate twenty-second temporary-link cleanup window.

Source or settings changes withdraw stale authority immediately. Replacement waits for exact known read and worker result/terminal closure. Unknown cleanup is sticky and blocks new work until reload. Cancellation, worker termination and known byte clearing do not prove native drain or physical memory erasure.

Finite supported limits

CSV input is at most 5 MiB; workbook input and each complete output at most 50 MiB. Up to 32 sheets or tables, 60,000 rows, 64 columns and 250,000 cells or aggregate finite slots are admitted, with separate XML, ZIP expansion, text and retained-byte caps. Inputs below these individual maxima may still refuse the whole action; worst-case device capacity is not guaranteed.

These bounded profiles do not establish native Excel/LibreOffice compatibility or general Office format, layout, font, script, accessibility, source-rights, regional, full-tool or release acceptance. Broader WebUT capabilities remain in construction.