Open and edit Excel files offline in your browser with XLSX Studio

2026-10-126 min read

excel

xlsx

spreadsheet

privacy

Sometimes you just need to look inside a spreadsheet, fix a few numbers and send it back — without installing Office or uploading a private file to a website. XLSX Studio does that entirely in your browser.

Opening a workbook

Drop an .xlsx, .xls, .ods, .csv or .tsv file onto the page. The file is read with the browser's File API and parsed locally, so it never leaves your device. Every sheet appears as a tab at the bottom of the grid. No file handy? Start from the budget, roadmap or team roster templates.

Editing like a spreadsheet

Click a cell to select it, then just start typing. Enter moves down, Tab moves right, Delete clears.
The formula bar shows the raw value or formula of the selected cell, such as =SUM(B2:B6).
Insert or delete rows and columns, and sort by the selected column with the header row kept in place.
Make cells bold or italic, change text and fill colors, alignment, and number formats (currency, percent, date).
Undo/redo remembers your last 50 changes.

Formulas that recalculate live

Formulas start with = and update as soon as any referenced cell changes. Supported functions include SUM, AVERAGE, COUNT, MIN, MAX, ROUND, ABS, IF, AND, OR, CONCAT, UPPER, LOWER, TRIM and LEN, along with arithmetic, & for joining text, and comparisons like >=.

Mistakes are shown clearly instead of silently: #DIV/0! for division by zero, #NAME? for an unknown function, and #CYCLE! when a cell refers back to itself.

Checking your data

The statistics panel summarises the selected column: filled and empty cells, sum, average, min and max. Repeated values in that column are highlighted, which is handy for spotting duplicate emails or IDs. The search box filters rows to those containing your text.

Saving your work

XLSX keeps every sheet, the formulas and the number formats, so Excel or Google Sheets can keep recalculating.
CSV / TSV export the calculated values of the active sheet. "Copy for Excel" puts tab-separated data on your clipboard to paste straight into another spreadsheet.
JSON uses the first row as keys — perfect for seeding an API or test fixture.
Markdown produces a table ready for a README or documentation page.

Limits worth knowing

XLSX Studio focuses on data and formulas. Charts, pivot tables, macros, and functions such as VLOOKUP are not edited here, and cell colors are not written into the saved file. For plain CSV cleanup, the CSV Viewer & Editor is even lighter.