Alternatives to SheetJS Pro, SpreadJS and Handsontable for Excel files

If you are choosing how to handle Excel files in a web application, you will meet the same names. They solve different problems, and the right one depends on whether you need to read data, show a file faithfully, edit it, or run what is inside it. This page sets them side by side, including us. Check each vendor's current documentation before deciding; features change.

The options

SheetJS is the standard parser. The community edition reads and writes many formats to a cell model; the Pro edition adds styles and more. It is a data library, not a renderer or a calculation engine, and it is excellent at what it does. Many other tools, including ours, use it for file decoding.
Handsontable is a grid component with an Excel-like feel and the HyperFormula calculation engine. It imports data from files through a parser; it does not reproduce a workbook's full formatting, charts or pivots.
SpreadJS is a full spreadsheet component with its own calculation engine, charts, PivotTables and xlsx import and export. It is mature and closed-source, priced per developer.
Univer is an open-source spreadsheet with a growing feature set and optional server components for collaboration.
Office Online embedding shows the real Excel but needs the file on OneDrive or SharePoint, a Microsoft licence for editing, and a network.
Server-side conversion (LibreOffice, Aspose and similar) turns the file into HTML or PDF. Static output, and the file leaves the browser.
Sheetwarden opens the file in the browser, calculates it with its own engine, renders it as saved, edits and exports it, and runs its VBA. Closed-source, per-developer licence, free to evaluate.

Side by side

Need	Sheetwarden	SheetJS	Handsontable	SpreadJS	Office Online	Server conversion
File stays in the browser	Yes	Yes	Yes	Yes	No	No
Render saved formatting, conditional formats, charts	Yes	Parse only	Partial	Yes	Yes	Static
Formula calculation	Yes	No	HyperFormula	Yes	Yes	No
PivotTables, slicers, timelines	Yes	No	No	Yes	Yes	Static
Legacy xls with drawings and charts	Yes	Cells and styles	Via parser	Check vendor	Yes	Usually
VBA macros and UserForms run	Yes	No	No	No	No	No
Edit and save back to xlsx preserving the rest of the file	Yes	Writes a new file	Via parser	Yes	Yes	No
Works offline, self-hosted	Yes	Yes	Yes	Yes	No	Needs server
Source available	On request under NDA	Community edition	Yes	No	No	Varies

How to choose

You need the numbers, not the look. SheetJS. It is the right tool and there is no reason to pay for a renderer.
You are building your own spreadsheet UI and importing data into it. Handsontable or Univer, with SheetJS for the file step.
You need a faithful view of customers' files, including pivots and old formats, and must not upload them. Sheetwarden or SpreadJS. We are stronger on legacy formats, verified calculation fidelity and macros; SpreadJS has a longer track record and a larger designer surface.
Your users have Microsoft licences and the files already live in SharePoint. Office Online embedding.
You need macros to run. As far as we know, this library is the only browser option.

Where we are weaker

We are newer and smaller. The feature support page is honest about partial areas: some 3-D chart styles render flat, advanced drawing effects have limits, and VBA parity is "core" rather than complete. Screen-reader support exposes the active cell and controls, not a full semantic table. If one of these matters to you, say so when you evaluate; the roadmap follows what customers send us.

Related guides

Try it now: open the live demo and drop in one of your own files. Nothing is uploaded. Then see the documentation or pricing.