How to use the Excel viewer
- Drag an .xlsx, .xls or .csv file onto the drop zone.
- The first sheet opens in a grid that looks like Excel. If the workbook has several sheets, switch between them with the sheet tabs at the bottom, just like in Excel.
- Type in the search box at the top right to keep only the rows containing that value. Matching cells are highlighted in yellow.
- Click a cell to see its address (such as B3) in the name box and its value or formula (such as =SUM(...)) in the formula bar. Column letters (A, B, C...), row numbers, gridlines, merged cells and column widths are shown the way Excel shows them.
It is built for files you just want to look at quickly: a quote from a supplier, an order export from an online store, or statistics downloaded from a public data portal.
How it works: the SheetJS parser
The spreadsheet is parsed with SheetJS (Apache-2.0). Like DOCX, XLSX is a ZIP archive of XML files, while the older XLS format is a binary format called BIFF8. SheetJS reads both and turns them into sheets and cells, which this viewer then draws as a lightweight grid.
- Displayed values: dates, currency and percentages are shown as formatted in the file.
- Formulas: cells show the last calculated result saved in the file, and the formula itself appears in the formula bar.
- CSV encoding detection: CSV files made in Korea are often saved as EUC-KR (CP949) rather than UTF-8. The viewer first tries strict UTF-8 and automatically falls back to EUC-KR, so Korean text does not turn into garbled characters.
Tips for large files
Drawing tens of thousands of rows at once can slow a browser down, so the grid shows up to 2,000 rows per sheet and tells you the total number of rows next to the sheet tabs. When Excel itself freezes or says a file is too large, opening it here first to check the contents can save a lot of time. The related guides explain more ways to handle large files.
Safe for tables with personal data
Customer lists, payroll sheets and survey responses become your responsibility the moment you upload them to an external server. This viewer reads the file only in your browser's memory, so nothing is uploaded or stored. If you need to share the data, mask phone numbers and email addresses first with the privacy masking tool on this site.
Frequently asked questions
Are formulas and charts shown?
Each cell shows the calculated value saved in the file, and clicking a cell shows its formula in the formula bar. Charts, pivot tables and macros are not displayed.
Will Korean text in CSV files be garbled?
No. The viewer reads the file as UTF-8 first and automatically retries as EUC-KR (CP949), so most Korean CSV files open correctly.
How many rows can it open?
Parsing is limited only by your device's memory. For performance the grid displays up to 2,000 rows per sheet.
Can I edit and save the file?
This tool is view-only. To turn the data into JSON use the Excel to JSON converter, and use Excel or a free spreadsheet program for editing.