Excel Compare Two Sheets Side by Side: Practical Methods

To view two Excel sheets beside each other, open both views, then choose View > View Side by Side; for a cell-by-cell comparison, use a formula such as =IF(A2=Sheet2!A2,"Match","Different") and fill it down. The first method helps you inspect layouts visually, while formulas and highlighting are better for finding exact differences across many rows.

What “side by side” can mean in Excel

People use “compare two sheets side by side” to describe two different tasks. You may want to display two worksheet grids at once so you can read or review them manually. Or you may want Excel to identify which values have changed, which rows are missing, or whether two datasets match. A split-screen view does not itself detect differences; it only makes both views visible. For a reliable audit, pair the visual view with formulas, conditional formatting, or a comparison tool.

The right method depends on how the sheets are organized. If both sheets have the same columns and records in the same order, comparing corresponding cells is straightforward. If rows are sorted differently, or one sheet has added or missing records, comparing A2 with A2 can give misleading results. In that case, match records by a stable identifier such as an invoice number, product code, or employee ID.

Open two worksheet views side by side

In Excel for Microsoft 365 on Windows, open the workbook and select View > New Window. Excel creates another window for the same workbook; it does not make a separate copy of the file. In each window, select the worksheet you want to inspect. Then choose View > View Side by Side. If you have multiple workbooks open, Excel can use the side-by-side command to display the open workbook windows instead.

To control the layout, select View > Arrange All and choose Vertical, then select OK. This is useful when Excel has arranged windows in a layout that is too short or too narrow. If you are comparing separate workbooks, open both files first and arrange their windows. The window title may show labels such as “:1” and “:2” when Excel has opened multiple views of the same workbook.

Use New Window when you need to view two tabs from one workbook at the same time.
Use View Side by Side when you want Excel to arrange two open workbook windows together.
Use Arrange All > Vertical if you want to set the layout yourself.

While the side-by-side view is active, Synchronous Scrolling can keep both windows moving together as you scroll. Turn it off when you need to inspect different areas independently. The command is on the View tab when the side-by-side feature is active. If the sheets have different row heights, frozen panes, or scroll positions, synchronized movement may not make corresponding records line up perfectly. You can still scroll either sheet to the relevant area and compare it manually.

Compare corresponding cells with a formula

For a simple comparison, put the sheets in the same workbook and use a helper column on one sheet. Suppose the first sheet is named January, the second is named February, and the values to compare are in column A, beginning in row 2. In January, enter this in B2:

With values in January!A2:A100 and the corresponding values in February!A2:A100, enter =IF(A2=February!A2,"Match","Different") in January!B2. If January!A2 contains 125 and February!A2 contains 130, the formula returns “Different”; if both contain 125, it returns “Match.” Fill the formula down through the rows you need to check.

If a sheet name contains spaces, surround it with single quotation marks. With values in the same A2 positions on sheets named January Data and February Data, enter =IF(A2='February Data'!A2,"Match","Different") in January Data!B2. Excel adjusts the row reference as you fill the formula down. If you compare across two separate workbooks, Excel can create an external workbook reference when you select the source cell; keep both files available and verify the reference before relying on the result.

A direct equality check is generally not case-sensitive: Excel treats “North” and “north” as equal in this comparison. It also treats two blank cells as equal. If capitalization matters, use EXACT. With the same cell layout as above, enter =IF(EXACT(A2,February!A2),"Match","Different") in January!B2. EXACT returns TRUE only when the text, including letter case, is identical. Decide whether case, extra spaces, or differences in data type should count before choosing a formula; for example, a number stored as text may need cleaning or conversion before the comparison is meaningful.

Highlight changes without building a separate report

Conditional formatting can make differences easier to scan directly in a worksheet. A practical approach is to create a helper column containing Match or Different, then highlight the Different results. Select the helper range, such as B2:B100, and choose Home > Conditional Formatting > Highlight Cells Rules > Text that Contains. Enter Different and choose a format. This avoids a common limitation: a conditional-formatting rule generally cannot directly refer to a cell on another worksheet unless the reference is handled through an allowed name or other setup.

You can also compare a whole row by making a helper formula that combines the checks for the fields that matter. For example, if names, dates, and totals are in columns A through C on both sheets, the formula can report a match only when all three corresponding values match. With those fields in January!A2:C100 and February!A2:C100, enter =IF(AND(A2=February!A2,B2=February!B2,C2=February!C2),"Match","Different") in January!D2. The result is Different if any of the three cell pairs differ. Add or remove comparisons to reflect the columns that define a meaningful match in your work.

For wider tables, consider applying conditional formatting to a helper result rather than trying to format every source cell with a complicated rule. Keep the helper column visible during review, or hide it only after you have saved a clear audit trail elsewhere.

When row order is different

Comparing the same row numbers works only when the same record appears in the same position on both sheets. If one list is sorted differently, row-by-row formulas may label many correct records as different. First decide which column uniquely identifies each record. Then look up the matching record on the other sheet and compare its fields. If an ID is not unique, a lookup can return the wrong occurrence or fail to distinguish duplicates; use a genuinely unique key or combine fields to define one.

For Microsoft 365, XLOOKUP can find a record by its key. Suppose IDs are in A2:A100 and amounts are in B2:B100 on the January sheet, while IDs and amounts are in columns A and B on February. With the February ID in A2 and amounts in B2:B100, enter =XLOOKUP(A2,February!A$2:A$100,February!B$2:B$100,"Not found") in January!C2. If the January ID in A2 is 104 and that ID has amount 75 in February, the formula returns 75; if the ID is absent, it returns Not found. You can then compare C2 with January!B2. XLOOKUP is available in Microsoft 365 and Excel 2021 or later, but not in some older perpetual versions.

Before comparing, check for duplicate IDs, leading or trailing spaces, inconsistent date formats, and blank identifiers. These can make two lists look different even when the underlying records are intended to match. A simple cleanup step, such as standardizing IDs and sorting both lists, often makes the comparison more dependable.

Compare entire workbooks with Spreadsheet Inquire

If the task is a formal comparison of two workbook files rather than two tabs, Microsoft’s Spreadsheet Inquire add-in may be an option. In supported Microsoft 365 or Office editions on Windows, enable it through File > Options > Add-ins. In the Manage box, select COM Add-ins and choose Go, then check Inquire if it is listed. The Inquire tab can provide a Compare Files command that reports differences between workbooks.

Inquire is not included or enabled in every Excel edition, and availability can depend on the organization’s Microsoft 365 plan or Office license. If the tab is missing, check your edition’s included features or ask your administrator rather than assuming a setting is broken. A workbook comparison tool can be useful for a broad structural review, but it does not replace checking whether a detected difference matters to the business question. For a small, clearly aligned table, helper formulas may be easier to understand and verify.

Choose a method and avoid common mistakes

Use a visual side-by-side view when the sheets are short, the goal is review, or formatting and layout matter. Use formulas when you need repeatable, cell-level results or when the tables contain enough rows that manual scanning is unreliable. Use key-based lookups when records may be reordered, and consider Inquire for a supported, workbook-level comparison. There is no single best method for every comparison: the structure and purpose of the data determine what counts as a real difference.

Confirm that you are comparing the intended sheets, workbooks, and versions.
Check that columns represent the same fields and that the compared ranges cover all relevant rows.
Use a unique key if records can move, and check that the key has no duplicates.
Decide how blanks, capitalization, spaces, dates, and numbers stored as text should be treated.
Keep a copy of the original files before making cleanup changes or overwriting data.

A frequent misconception is that View Side by Side automatically checks for changes. It does not; it displays windows. Another is that a formula comparing A2 with A2 proves two complete lists are identical. It proves only that those particular cells match, and only if the rows correspond. For a dependable result, compare every relevant field, account for missing records, and review the formula range after filling it down.

Frequently Asked Questions

Can I compare two tabs in the same Excel workbook?
Yes. Choose View > New Window, select a different worksheet in each window, and then use View > View Side by Side. For an automatic check, put a comparison formula in one sheet and reference the other sheet.

Does Excel have a built-in “compare sheets” button?
Excel’s side-by-side view is for viewing, not detecting changes. Some supported Windows editions offer the Spreadsheet Inquire add-in for comparing workbooks; for many sheet comparisons, formulas or conditional formatting are the more accessible options.

How can I find values that appear on one sheet but not the other?
Match the lists using a unique ID rather than assuming the same records are on the same rows. In Microsoft 365 or Excel 2021 and later, XLOOKUP can return Not found when an ID has no match; check for duplicate IDs before trusting the result.

Can Excel compare two sheets when their rows are in a different order?
Yes, but a direct row-by-row equality formula is not enough. Look up each record by a unique key, then compare the fields returned for that record. If the key is duplicated, make it unique or use a combination of fields.

Can I do this in Excel for Mac or Excel for the web?
Excel for Mac and Excel for the web may present window-management commands differently from Windows, and available comparison add-ins vary. If the side-by-side command is unavailable, open the workbook in separate windows and arrange them using the options available in that version; formulas such as IF and ordinary cross-sheet references remain useful for data checks.

Try it: the Date Difference Calculator: days, months, years and weekdays between two dates, with the DATEDIF formulas.

More in How-to basics

Sources: Function behaviour and menu paths: Microsoft Support documentation for Excel. Method & sources

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