This tool lets you compare two Excel files cell by cell in your browser, value and formula, and shows which cells one version changed, added or removed. The usual case is a file that went out and came back. You sent the regional forecast to six managers on Monday, one returns it on Thursday with "a few tweaks", and you need to know which cells those were before the numbers go into the board pack.
How to compare two Excel files
- Drop the older version on the "Older file" box and the newer version on the "Newer file" box, or click each to browse. Both can be .xlsx, .xlsm, .xls, .xlsb or .ods, up to 20MB each. Both are read in your browser, and neither is uploaded.
- The compare starts as soon as both files are in, on the first sheet they share by name (ignoring case, so "Forecast" pairs with "FORECAST").
- Read the two sheets side by side. Changed cells are boxed in amber, added cells in green on the newer side, removed cells in red on the older side. Scrolling one sheet scrolls the other. Click a cell to see what it holds in each file, formula included.
- Click "Next change" and "Previous" to step through the differences, or tick "Hide unchanged rows".
- Pick another pair in the "Older sheet" and "Newer sheet" lists. The files stay open, so nothing is read twice. Hidden sheets are listed, marked "(hidden)", and two sheets with different names can be paired.
- Under the sheets, the change list gives each cell's address, the kind of change, what it was and what it is now. "Copy all" copies it as a table to paste into Excel.
What counts as a change
The compare reads two things in each cell: the value and the formula.
| Older file | Newer file | Result |
|---|
| 1,200 | 1,250 | Changed |
| Empty | 42 | Added |
| Q3 budget | Empty | Removed |
=B12*C12 in D12 | =B13*C13 in D13, after a row went in above | No change |
=SUM(B2:B10) showing 900 | Same formula, now 950 because B4 changed | Changed, with both results |
| 1 (a number) | 1 (text) | Changed |
| 1200 in General format | 1200 shown as $1,200.00 | No change |
The number-against-text row catches people out. An ID column re-exported from a CRM can come back as identical-looking text, and a VLOOKUP on it returns #N/A.
Why one inserted row doesn't flag the rest of the sheet
The usual ways of comparing two sheets in Excel, an IF formula or a conditional formatting rule, match row 50 with row 50. Insert one row near the top of the newer file and every row below it sits opposite the wrong row. A 4,000-row price list with one new product at row 12 turns into 3,989 rows of noise.
This tool lines up the rows before it compares cells. The new row shows once, in green, opposite an empty shaded row on the older side, and the rows below it stay unchanged.
Two cases still make noise on the free page. Columns are compared by position, so a column inserted at C makes every cell to its right show as changed. Within a run of inserted and deleted rows, rows pair by position, so a row cut, pasted lower down and edited can read as one row deleted and another inserted. Pro lines up columns, can match a re-sorted list by ID, and matches more edited rows by content.
Formulas that were copied, moved or typed over
Insert a row above row 12 and Excel rewrites =B12*C12 in D12 as =B13*C13 in D13. Same calculation, different text. In R1C1 form, Excel's other way of writing references, both read =RC[-2]*RC[-1], and that's the form the tool compares. A formula that moved with its row isn't flagged, and neither are the copies filled down a column.
The change that does the most damage in a returned file is a formula someone typed over with a number, often the very number it was showing. The total looks right today and stops updating next month. It shows as a changed cell, and in the copied change list its "Was (formula)" column holds the formula while "Now (formula)" is empty.
Comparing two files in Excel without this tool
Excel's own tool is Spreadsheet Compare. Microsoft lists it only for Office Professional Plus 2013, 2016 and 2019 and Microsoft 365 Apps for enterprise, in Excel for Windows. Microsoft 365 Personal, Family and Business Standard aren't on that list, and no Mac is. If you have it, type Spreadsheet Compare in the Start menu, click Home > Compare Files, and put the older file in "Compare" and the newer one in "To". It can also check formatting and macros.
Without it, the manual route is a formula on a third sheet. Copy one sheet into the other workbook (right-click its tab, Move or Copy, pick the workbook under "To book", tick "Create a copy"), name the two sheets Old and New, then put this in A1 of a new sheet and fill it across and down:
=IF(Old!A1<>New!A1,"Old: "&Old!A1&" | New: "&New!A1,"")
For colour instead, select New's data from A1 and add a rule under Home > Conditional Formatting > New Rule > Use a formula, with =A1<>Old!A1. Both methods compare by position, so they break on an inserted row, and they compare results only: an edited formula with the same result passes.
Limits
- One sheet pair at a time. Chart sheets and macro sheets are left out of the lists.
- Values and formulas only. The free page doesn't compare formatting, comments, charts, defined names, data validation or conditional formatting. Pro compares names, notes and comments, validation and conditional formats in .xlsx and .xlsm files, but not fonts, fills or charts either.
- 100,000 changes a sheet. The summary counts the rest; only the first 100,000 are listed and boxed.
- Very large sheets. Rows that can't be lined up within the time limit per sheet are compared at the same row number, and the page says so (Pro does the same for rows or columns).
- No download, only Copy all. The tool never merges and never changes either file.
- 20MB a file, and one newer file at a time: drop several and the first is compared.
- Password to open. The page explains the file can't be read. Save a copy without the password in Excel and compare that.
What the Pro compare adds
A Pro account compares the whole workbook in one run: every sheet pair, with sheets added, removed, renamed (paired by content) or moved in the tab order. It takes files up to 50MB, still runs in your browser, and costs $9 a month or $90 a year, the same subscription as the Workbook Audit.
Pro lines up columns as well as rows, matches an edited row to its older version by content, and tints a row that moved unedited blue. For a re-sorted data list, it can match rows by one or more ID columns instead, such as an order and line number, so order stops counting as a change. An ID repeated in either file, or a row with an empty ID, isn't matched; both are listed and tinted yellow.
Every change gets a type (value edited, formula edited, formula typed over, value made a formula, result changed), with a count and a filter for each. Pick an edited formula to see what changed in it, named: a reference repointed, a range end moved. Totals whose range didn't grow over inserted rows are flagged, and changed results are grouped under the edits that moved them. Options set what doesn't count: numbers within a tolerance or equal after rounding, case, leading and trailing spaces, empty text against a blank cell. None of these options apply to formulas.
"What these changes broke" runs the Workbook Audit on both files and shows which issues are new, fixed or still there. In .xlsx and .xlsm files, Pro also compares structure: defined names, hidden sheets, rows and columns, merged cells, validation and conditional formatting rules, protection, external links, data connections, macros, notes and comments, and the author, company and title.
Two downloads. The change report comes as an .xlsx with a filterable Changes table, or a PDF with Reviewed by and Date lines for sign-off. The marked copy is the newer file itself (.xlsx or .xlsm only) with each changed cell filled in a colour for its type, plus a Changes sheet; no value or formula in it changes.
For the forecast that went to six managers, drop the master as the older file and up to 20 returned copies as the newer (200MB in all, master included). Pro compares each copy with the master in turn: one table, a row per copy, each row opening that copy's full compare.
If the question is only which IDs in one column turn up in another list, paste both columns into Compare Two Columns.
Questions
How do I compare two Excel files for differences?
Put the older and newer versions side by side and mark every cell whose value or formula differs. Excel's own tool for this, Spreadsheet Compare, only comes with some Windows editions. Without it, either copy both sheets into one workbook and fill an IF formula across a third sheet, or use a compare tool that lines up inserted rows, since the formula method flags every row below an insertion.
Does Excel have a built-in compare feature?
Yes, Spreadsheet Compare, but Microsoft lists it only for Office Professional Plus 2013, 2016 and 2019 and Microsoft 365 Apps for enterprise, in Excel for Windows. Open it from the Start menu by typing Spreadsheet Compare, or from Inquire > Compare Files if the Inquire add-in is on. It doesn't run on a Mac.
Why does every row show as different after one row was inserted?
Because the comparison matched rows by number, so after the new row each row is checked against the one above it in the other file. A cell-by-cell IF formula or a conditional formatting rule like =A1<>Sheet2!A1 always does this. A compare that lines up rows first reports one inserted row and leaves the rest alone.
Can I compare every sheet in two workbooks at once?
On the free page, no: it compares one sheet pair at a time, and switching to another pair doesn't read the files again. A Pro account compares every sheet pair in one run, finds sheets that were added, removed, renamed or moved in the tab order, and lists each sheet with its number of changes.
Does it compare formulas or just values?
Both. A cell counts as changed when its value changed or when its formula does something different, and formulas are compared in R1C1 form, so a formula that moved down with its row after an insertion isn't flagged just because its references now name the next row. A formula whose result changed because a cell it reads changed also shows, with its old and new results.
Does the compare pick up formatting changes?
Not by default. A new fill colour or font on a cell whose value is the same is never a difference, and neither is a new number format unless you ask Pro to show number-format changes. If formatting is what you need to check, Spreadsheet Compare's Cell Formats option covers it on the Windows editions that include it.
How do I compare two Excel sheets side by side in Excel?
Open both workbooks and click View > View Side by Side; Synchronous Scrolling turns on with it, so both windows scroll together. For two sheets in the same workbook, click View > New Window first, then View Side by Side. It only lines up as long as neither sheet has had rows inserted or deleted.