Excel (XLSX) Viewer
Open .xlsx and .xlsm workbooks in your browser without Excel or a Microsoft account. Switch between sheets and read the cells in a fast, scrollable table, with nothing uploaded.
Free, no sign-up, and fully client-side. Your file never leaves your browser. Opens .xlsx, .xlsm.
Open the viewer and drop a file to get started.
What is an XLSX file?
An .xlsx file is a Microsoft Excel workbook. Despite looking like a single document, it is really a zip archive of XML parts: one per worksheet, a shared-strings table, and workbook metadata (the Office Open XML format). That is why you cannot just open it in a text editor to see the values.
ViewKit unzips the workbook in your browser, resolves the shared strings, and renders each sheet as a table you can page through. It is a quick way to peek at a spreadsheet on a machine without Excel, and nothing is uploaded.
What you can do with the Excel viewer
Every sheet
Switch between all worksheets in the workbook from a simple sheet picker.
Shared strings resolved
Text stored in the workbook’s shared-string table is resolved so cells show their real values.
Fast, scrollable table
Rows are virtualized, so large sheets scroll smoothly and columns resize to fit their content.
No account needed
Runs entirely in the browser, with no Excel install and no Microsoft or Google sign-in.
How to open a Excel file
- 1
Drop your .xlsx or .xlsm file onto the box above (or click to browse). It is read in your browser, nothing uploads.
- 2
Pick a worksheet from the sheet switcher.
- 3
Scroll the cells; drag or double-click a column edge to resize it.
Doing the same thing in code
Reading the same workbook in Python:
import pandas as pd
sheets = pd.read_excel("book.xlsx", sheet_name=None) # None means every sheet
for name, df in sheets.items():
print(name, df.shape)
print(sheets["Sheet1"].head())This requires openpyxl and reads every sheet into memory. The same type inference applies as with CSV, so text codes may be converted to numbers. This page renders the cells as they are stored in the workbook.
Excel viewer: frequently asked questions
Do I need Excel installed?
No. The workbook is read and rendered in your browser, so you can view it on any machine without Excel or a Microsoft account.
Can it open the older .xls format?
No. Despite the similar name, .xls is a completely different binary format from before Office Open XML, and it is not supported. Opening it once in Excel or LibreOffice and saving as .xlsx converts it.
Why do my dates show as numbers like 45123?
Excel stores a date as a day count from an epoch, and records that it is a date in the cell’s number format rather than in the value. A cell with missing or unusual formatting therefore shows the underlying serial number. The value is intact; only the display format is absent.
Does it open password-protected workbooks?
No. An encrypted workbook cannot be unzipped without the password, so it will not open. Remove the protection in Excel and save a copy first.
Does it read multiple sheets?
Yes, every worksheet in the workbook is available from the sheet switcher.
Are formulas and formatting shown?
Cell values are shown (the last saved result for formula cells). Styling, charts and macros are not rendered; this is a fast viewer, not an editor.
Is my spreadsheet uploaded?
No. Parsing happens entirely in your browser; the workbook’s contents never leave your machine.