Add Serial Number to Excel Online Free

Insert a new column with sequential numbering (1, 2, 3...) automatically.

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Drag & Drop or Click to Upload Excel File

* A new column will be added at the beginning (Column A).

Restore Order to Your Data

A dataset without unique identifiers is chaotic. If you sort your data by name or date, you lose the original sequence. By using the "Add Serial Number" tool, you create a permanent reference point. Even if you shuffle your data later, the serial number stays attached, helping you track the original entry order.

Instant Column Insertion

Manually inserting a column, typing '1', '2', and dragging the handle down for 10,000 rows is tedious and can freeze your computer. Our tool automates this. It instantly inserts a new column at the very beginning of your sheet and fills it with sequential numbers, no matter how large your file is.

Customizable Numbering

Need to start numbering from 1001 for Invoice IDs? Or maybe you want the header to say "ID" instead of "S.No"? This tool gives you full control. You can define the column header name and the starting number, making it perfect for generating Product IDs, Membership Numbers, or Ticket Codes.

Smart Data Detection

The tool is intelligent enough to know where your data ends. It won't fill numbers into empty rows down to infinity. It scans your sheet to find the last row with actual data and stops numbering exactly there, keeping your file clean and professional.

Add Serial Number to Excel Automatically

Adding serial numbers in Excel is one of the most common data-management tasks. Whether you are preparing student lists, employee records, invoice tables or survey data, serial numbering helps maintain order and reference.

Why Use Automatic Serial Numbering?

Manually dragging numbers in Excel becomes slow and unreliable when dealing with thousands of rows. Automatic serial number generation eliminates errors, saves time and ensures perfect sequencing.

Custom Starting Number Support

This tool allows you to start numbering from any value such as 1001, 5000 or even 0. This is extremely useful for invoice IDs, product codes, ticket numbers and registration systems.

Insert Serial Number Column Automatically

The tool automatically inserts a new column at the beginning of your Excel sheet and fills serial numbers only for rows that contain data.

How to Add Serial Number in Excel Online

  1. Upload your Excel file (.xls or .xlsx).
  2. Enter column header name.
  3. Select starting number.
  4. Click add column and download.

Excel Files Supported

  • XLS
  • XLSX
  • Multiple sheets (first sheet auto-processed)

Who Should Use This Tool?

  • Students and teachers
  • Office staff
  • Accountants
  • Data entry operators
  • Small business owners

Privacy & Security

All Excel processing happens directly in your browser. Files are never uploaded to any server, ensuring complete privacy.

Frequently Asked Questions

Is this tool free?
Yes, unlimited free usage.

Are files uploaded?
No. Files stay on your device.

Can I start serial number from 1000?
Yes, any number is supported.

Does it work on mobile?
Yes, works on Android browsers.