Client-side spreadsheet protection
Escape Excel Online
Protect scientific identifiers and text-like values from Excel’s automatic type conversion without sending the source file to a server.
What the tool protects
Spreadsheet software can reinterpret text that resembles another data type. That behavior is especially dangerous for accessions, sample identifiers, barcodes, plate positions, gene symbols, and exported measurements. The protection engine can flag and store these values as text:
- date- and time-like strings such as
SEP7,1-08, or3:00; - identifiers with leading zeros such as
00123456; - long integers that may lose precision or display in scientific notation;
- scientific-notation-like identifiers such as
2310009E13or2E4; - text beginning with
=,+,-, or a single quote that may be treated as a formula or transformed on import; - numeric-looking values containing commas under configurable strictness.
Safer output choices
| Output | Best use | Preservation behavior |
|---|---|---|
| Protected XLSX | Opening directly in Excel or compatible spreadsheet applications | Risky selected values are written as explicit text cells; other matrix values are classified conservatively. |
| Patched XLSX/XLSM | Existing unsigned OOXML workbooks | Only approved cell XML is replaced; unmodified package parts are checked byte-for-byte. |
| Patched CSV/TSV | Repairing text while retaining original delimiters, quoting, line endings, and untouched bytes | UTF-8 source values are replaced using recorded byte spans. |
| Legacy escaped TSV | Compatibility with older Escape Excel workflows | Uses ="text" for selected risky fields and is clearly labeled as a legacy output. |
Why the tool does not simply rewrite every cell
A generic read-and-export library can normalize dates, numbers, formulas, XML ordering, quoting, delimiters, or workbook package metadata. This implementation starts by inventorying the format and reconciling independent readers. It then uses the narrowest available write path and verifies the result before exposing it for download.
Important boundaries
Encrypted packages cannot be inspected. Digitally signed OOXML workbooks are scan-only because modification invalidates the signature. Legacy binary .xls files are detected but not edited. Formula cells are reported and excluded from automatic replacement. Native raw-DEFLATE streams are optional: the package includes an independent JavaScript inflater for compressed XLSX/XLSM/ODS input and can write stored ZIP entries when native compression is unavailable.