Spreadsheet Editor

How to edit a CSV or XLSX spreadsheet online without uploading the file?

Open AnyTool Spreadsheet Editor, drop a .csv, .tsv or .xlsx file, and edit it in a virtualized grid with a real Excel-compatible formula engine (A1 refs, ranges, ~280 functions, live recalc). Export back to CSV, XLSX or JSON. Everything runs in your browser - the file is never uploaded.

Edit CSV, TSV and XLSX in an editable, virtualized grid that scrolls tens of thousands of rows
Real formula engine: A1 references, ranges and ~280 functions (SUM, IF, VLOOKUP, INDEX/MATCH, COUNTIF, dates)
Sort, find and replace, insert or delete rows and columns, undo or redo, and export to CSV, XLSX or JSON
100% in your browser - no upload, no signup, works offline

What is

Client-Side Spreadsheet Editor

A client-side spreadsheet editor opens and edits CSV and XLSX files directly in the browser, with a formula engine that recalculates dependent cells, so spreadsheet data is never sent to a server.

Developer Tools

Related terms

Formula EngineXLSX ParsingCSV EditingDependency Graph Recalculation

Frequently Asked Questions

AnyTool Spreadsheet Editor is 100% client-side. CSV files are parsed with PapaParse and XLSX files with ExcelJS inside a Web Worker, all in your own browser tab. Nothing is uploaded, there is no server or runtime CDN, and it keeps working offline after the first load.

No. The file is parsed and edited entirely in your browser and is never uploaded or sent to any server.

The editor loads a real Excel-compatible formula parser that understands A1 references and ranges and supports roughly 280 functions such as SUM, AVERAGE, IF, VLOOKUP, INDEX/MATCH, COUNTIF, ROUND, plus date and text functions. Editing a cell recomputes only its dependents through a dependency graph with cycle detection, so totals update live.

Yes. It uses a real formula engine with A1 references, ranges and around 280 functions, including IF, VLOOKUP and SUM.

The grid is virtualized, so it stays smooth scrolling tens of thousands of rows, and XLSX parsing runs in a Web Worker to avoid freezing the tab. It is a focused editor and calculator: it does not include charts, pivot tables, macros or real-time multi-user collaboration, and full Excel style fidelity (conditional formatting, merged cells) is only partially preserved.

It handles large sheets via a virtualized grid, but it does not build charts, pivot tables or macros.

Click Open or drag and drop a .csv, .tsv or .xlsx file onto the grid to load it. Edit cells, formulas and formatting, then use Export to download CSV, XLSX or JSON, or copy the whole sheet as TSV to the clipboard. An optional on-device autosave (IndexedDB) keeps your work across refreshes and clears on one click.

Drag a CSV or XLSX onto the grid (or use Open), edit it, then export as CSV, XLSX or JSON, or copy as TSV.

Open and edit CSV, TSV and XLSX in a virtualized grid with a real Excel-compatible formula engine and live recalc, fully in your browser.

Features

Real formula engine: A1 refs, ranges and ~280 functions (SUM, IF, VLOOKUP, INDEX/MATCH, COUNTIF, dates, text) with live dependency-graph recalc
Virtualized grid that scrolls tens of thousands of rows; XLSX parsing runs in a Web Worker
Sort, find and replace, insert or delete rows and columns, undo or redo, column resize, bold, alignment and number formats
Export to CSV, XLSX or JSON, copy as TSV, and optional on-device autosave via IndexedDB
100% client-side - no upload, no server, no runtime CDN, works offline

PriceFree

CategoryDeveloper Tool

PlatformAll (browser-based)

PrivacyData never leaves your device

Input: CSV, TSV, XLSX, XLS

Output: CSV, XLSX, JSON, TSV (clipboard)

Detailed Explanation

How It Works

In-Browser CSV and XLSX Editor with a Formula Engine

AnyTool Spreadsheet Editor opens CSV, TSV and XLSX files in an editable, virtualized grid and evaluates spreadsheet formulas locally. CSV is parsed with PapaParse and XLSX with ExcelJS, while a fast formula parser provides A1 references, ranges and roughly 280 Excel-compatible functions. All parsing, editing and calculation happen in the browser.

Supports CSV, TSV and XLSX input
Exports CSV, XLSX and JSON, and copies TSV
Formula engine covers ~280 functions including SUM, IF, VLOOKUP and INDEX/MATCH

Technical Details

Dependency-Graph Live Recalculation

Editing a cell does not recompute the entire sheet. The editor builds a dependency graph of formula cells with cycle detection and recomputes only the cells affected by a change, so totals and downstream formulas update instantly. XLSX files are parsed inside a Web Worker and the grid is virtualized so large sheets stay responsive.

Recomputes only affected dependents, not the whole sheet
Cycle detection guards against circular references
Virtualized grid scrolls tens of thousands of rows smoothly

Limitations

Privacy Model and Honest Limits

The tool is fully client-side with no upload, no server and no runtime CDN, and it works offline after the first load; an optional IndexedDB autosave keeps work on-device and clears on one click. It is a focused editor, not a full office suite: it does not provide charts, pivot tables, macros or real-time collaboration, and full Excel style fidelity such as conditional formatting and merged cells is only partially preserved.

No upload, no server, no runtime CDN
Optional on-device autosave via IndexedDB
No charts, pivot tables, macros or multi-user collaboration

AnyTool Spreadsheet Editor vs typical online spreadsheet tools
Capability	AnyTool	Typical alternative
Privacy / no upload	Yes - 100% client-side	Often server-side or cloud-stored
Account / signup	None	Often required (Google, Microsoft, Zoho)
Price	Free	Freemium / paywall or SDK license
CSV + XLSX + real formula engine	Yes, all in one free tool	CSV-only or thin XLSX demo
Works offline	Yes, after first load	Usually needs a network

Charts, pivot tables, macros and real-time collaboration are out of scope and remain stronger in cloud suites.