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dotXLSOpen Workspace

Find Missing Numbers in Sequence

Find gaps and duplicate values in a numeric sequence without changing the source worksheet.

Choose a numeric sequence column, analyze gaps and duplicates, preview missing values, then create a separate Missing Numbers worksheet.

Paste Data

Copy cells from Excel or Google Sheets and paste them here.

Import a spreadsheet file

Import CSV or XLSX data into the current dotXLS workspace. Files are processed in your browser.

Tools

Choose a numeric column. The tool finds missing integers between the smallest and largest valid values and reports duplicate values. The source worksheet remains unchanged.

Find missing numbers

Safety limit: the analyzed numeric span must not exceed 100,000 values.

Undo and Redo controls are available with the current grid.

Paste spreadsheet data to create your workspace.

Name	Department	Amount
Ahmed	Sales	1200
Maria	HR	950

Your data stays in this browser tab and is not sent to WordPress.

Export result

Download the current workspace data after editing or cleaning.