Excel File Viewer and Reader

What the viewer shows

After you choose a file, the page lists its sheets. The selected sheet is rendered as an HTML table with a sticky header, so column names stay visible while you scroll. A status line reports the row and column count, and a notice appears when the sheet exceeds the viewer's window.

The “First row is header” switch controls whether the first row is styled as a header. Turn it off for a sheet that starts directly with data. The setting affects presentation, not the underlying values.

A search field filters visually: matching cells are wrapped in a highlight and the table scrolls to the first match. The search works on the rows currently loaded, not on the hidden remainder of a very large sheet.

How to open a file

1. Drag a spreadsheet onto the dropzone, or click to browse for a file.
2. Wait for the sheet list to appear.
3. Choose the sheet you want to inspect.
4. Set the header option if the first row is a label row.
5. Use the search box to find a value in the visible rows.
6. Click Download CSV to export the current sheet.
7. Click Clear to remove the file from the page.

The viewer accepts .xlsx, .xls and .csv. It does not ask for an email address and does not create a workbook library. Closing the tab discards the file.

The viewing window

The table displays up to 300 rows and 60 columns. That is enough for a typical price list, roster or small dataset, but not for a full financial model. When the sheet is larger, the notice tells you that the preview is truncated.

Search only sees the loaded rows, so a value beyond row 300 will not be found. If you need to inspect the rest of the sheet, split the file into smaller ranges or open it in a spreadsheet application. The CSV download is different: it exports the whole selected sheet, not just the visible 300 rows.

Wide sheets can be hard to read on a phone. Scroll horizontally within the table container rather than zooming out; the sticky header and column alignment remain easier to follow.

Reading values and dates

The viewer reads cell values rather than rendered formatting. A date may appear as a JavaScript date string, and a currency value may lose its symbol. A formula is shown as its stored result, not as a live calculation. If the exact display format matters, compare it with the original file.

Empty rows at the end of a sheet may collapse, and blank cells may appear as empty strings. That is normal for a browser-based preview. It does not mean the original workbook has lost data.

Merged cells are not reconstructed as spans. The values appear in the table in a simplified form, which can make a merged header look repetitive or misaligned. Use the original file when the visual layout is part of the information.

Exporting CSV

The CSV button exports the current sheet using SheetJS, not the truncated preview. The filename combines the original base name and the sheet name. The export is plain CSV, so colours, formulas, comments and multiple sheets are not included.

CSV is a good format for moving data into another tool, but it has no standard way to represent dates, leading zeros or long numbers. A phone number or a product code may lose its leading zero when opened in another program. Check the exported file before relying on it for identifiers.

If the sheet contains commas, quotes or line breaks, a proper CSV writer escapes them. The receiving application must also parse them correctly. Test the import on a small sample first.

Privacy, limits and common issues

The file is parsed in the browser. The page does not upload the workbook or store it in an account. That is a privacy advantage for internal data, but it also means the viewer cannot open a file from a URL or a cloud drive without downloading it first.

A password-protected workbook will not open because the browser does not have the password. A corrupt file, a renamed file or an unsupported format will also fail. If a sheet appears empty, check that it is not hidden and that it contains values rather than only formatting.

The viewer is not an editor. It cannot change a cell, recalculate a formula or save the workbook back to XLSX. Use it to inspect and export, then edit in a spreadsheet application.

Comparing sheets and checking values

The sheet selector makes it easy to compare two tabs from the same workbook. Open one sheet, note a row or a total, switch to the other, and look for the same value. The viewer does not calculate differences or run formulas, so do the comparison by eye or export both sheets to CSV and use a spreadsheet or diff tool.

When a value looks wrong, check whether the cell contains a formula or a formatted number. The viewer shows the stored result, not the formula that produced it. A date may be a serial number in the original file and a formatted date string in the preview. If the exact representation matters, compare with the source application.

Use the search box to locate an identifier, then read across the row. The highlight scrolls to the first match, but it does not filter the table or hide non-matching rows. For a large sheet, combine search with the header row and the visible row count to avoid mistaking a truncated view for the whole dataset.

Exporting a sheet for another tool

The CSV download is the bridge to other software. Export the current sheet, open the file in a text editor or import it into a database, and check the delimiter and encoding. A value containing a comma or a line break should be quoted by the CSV writer; if it is not, the receiving tool may split it into extra columns.

CSV does not preserve data types. A product code such as 00123 may become 123, and a long account number may be converted to scientific notation by a spreadsheet. Format those columns as text in the receiving application, or use a different export format if precision matters.

If the sheet contains sensitive data, remember that the CSV file is now on your device and may be synced by your downloads folder or backup software. Delete the export when you are finished, and avoid opening it on a shared machine.

Frequently Asked Questions