SpreadJS v19.1 Released!

We’re excited to announce SpreadJS v19.1, a focused release that makes building spreadsheet apps faster and smoother.

This release delivers a new VS Code spreadsheet editor, faster formulas with custom functions in Calc Worker, Excel-style What‑If Analysis, and richer formatting and workflows. Ship more capable spreadsheet experiences with less effort using SpreadJS 19.1!

Ready to dive into the details? Let’s explore what’s new in each area of SpreadJS v19.1.

What’s New in SpreadJS v19.1

• Designer Enhancements
• Formulas
• Conditional Formatting
• Cell Formatting
• What-If Analysis
• Import/Export
• Data Manager
• TableSheet
• PivotTable
• Collaboration Server
• DataCharts
• GanttSheet
• UI and UX Enhancements
• Framework Support

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Designer Enhancements

Templates Configuration & Default Template

The Designer now includes a templatesConfig option, allowing users to define and apply pre-configured styles and formats to new workbooks. By providing a URL to a template configuration file, users can load various template types from remote sources or pre-loaded data, ensuring consistent workbook creation. This feature simplifies workflow by applying default or selected templates upon initialization or 'Reset' operations, with asynchronous loading preventing immediate overwrites.

Templates from Configuration

Learn more in our Designer Template documentation or try our online Designer demo.

Search Added to Formula Dialog 

The Search feature in the Insert Function dialog lets users quickly find the right spreadsheet function by typing keywords and instantly filtering results. It surfaces the best matches in a Recommended list (based on names, descriptions, categories, and arguments), supports keyboard navigation, and makes inserting functions faster and easier.

Learn more in our Designer Function Dialog docs.

SpreadJS XLSX Editor for VSCode Plugin

The new SpreadJS Designer VS Code plugin brings full spreadsheet design capabilities directly into your editor, letting you open, edit, and save .sjs, .ssjson, Excel (.xlsx/.xlsm/.xltm/.xltx), and .csv files without leaving VS Code. It adds an “Open with SpreadJS” context-menu action, handles password‑protected Excel files with inline prompts, and integrates with VS Code’s save flow and command palette for creating new files. The plugin is tailored for the VS Code environment with a customized file menu, support for classic/toolbar ribbon modes, automatic light/dark theme adaptation, and localization via language and culture settings.

SpreadJS XLSX Editor for VSCode

Install this extension from the VS Code Marketplace or learn more in our Designer VSCode plugin documentation.

Formulas

Custom Functions in Calc Worker

SpreadJS now lets your custom functions run directly inside the Calc Worker, so they’re evaluated off the UI thread for faster, smoother spreadsheets—especially with heavy or async logic. By adding a simple supportCalcWorker() flag to your custom Function or AsyncFunction, SpreadJS serializes the function and executes it in the worker. In our benchmarks, Calc Worker improved performance up to 3 times faster!

Learn more in our calcWorker documentation or try our Custom Function in Calc Worker demo.

Value and Array to Text Functions

SpreadJS introduces two new functions, VALUETOTEXT and ARRAYTOTEXT, designed to enhance text conversion within your spreadsheets. VALUETOTEXT converts any single value into text, while ARRAYTOTEXT performs the same conversion for an array of values, making it easier to manipulate and display data consistently. 

Learn more in our VALUETOTEXT and ARRAYTOTEXT documentation  or try our Text Function demos.

Conditional Formatting

Top/Bottom Percent Rule

This feature enhances SpreadJS with native percent-based Top/Bottom conditional formatting, aligning its behavior with Excel. It calculates "hits" based on the number of non-empty numeric cells (N) in a range, using max(1, floor(N × P)) when N > 0 to ensure at least one match, and 0 when N = 0. This change improves data scale stability and Excel import compatibility, and can be enabled via the isPercent property in NormalConditionRule or conditionalFormats.addTop10Rule. 

Learn more in our Top 10 Rule documentation.

Sparkline Rules in Conditional Formatting

SpreadJS now lets you drive Sparklines entirely through conditional formatting rules, turning cell values and ranges into mini‑charts without writing formulas. New built‑in placeholders like $CF_RANGE$ and @ make it easy to target the rule’s range and current cell, so you can quickly build visual KPIs such as pie, gauge, lollipop variance, bullet, and even custom sparklines across Worksheets.

Sparkline Rule

Learn more in our Sparkline Rule documentation or try our Sparkline Rule demo.

Cell Formatting

Single and Double Accounting Underline

SpreadJS now adds Single Accounting and Double Accounting underline styles, closing a key gap with Excel and improving financial-report formatting and Excel import/export fidelity. These underlines render using Excel-aligned rules (baseline-based positioning, adaptive spacing by font size, and smart width behavior for numbers vs. text), with graceful fallback when cell height is too small. 

Learn more in our Text Decoration docs or try our Text Decoration demo.

Picture In Cell

SpreadJS now supports inserting Excel-style pictures directly into cells as “image rich data,” so images behave like real cell values that can be sorted, filtered, searched, used in lookups, and even included in certain formulas and pivots. Designers can easily switch between “picture in cell” and floating images, control sizing and alignment, and rely on shared internal storage for repeated images to keep workbooks efficient and compatible with Excel behavior. 

Learn more in our Image Rich Data documentation or try our Image Rich Data demo.

Named Cell Templates

SpreadJS introduces Named Cell Templates, letting you package styles, conditional formatting, data validation, and cell states into reusable templates that can be applied to any worksheet, TableSheet, GanttSheet, or ReportSheet range with a single call. These templates are workbook‑level, apply‑only (no live binding), and dramatically cut repetitive setup while keeping your cell configurations consistent across complex models.

Learn more in our Named Cell Templates documentation or try our Named Cell Template demo.

What-If Analysis

Support What-If Analysis Data Table

SpreadJS now supports Excel-style What-If Analysis data tables through a new SJS.TABLE function, which simulates different input scenarios and returns the corresponding calculation results as dynamic arrays. This design removes many of Excel’s structural limitations (like rigid data table layouts), while still importing Excel data tables as SJS.TABLE formulas and attempting to export them back when possible. To keep large models responsive, a new partial calculation mode and enhanced CalculationProgress event let you control and monitor the performance impact of these simulations. 

Learn more in our What-If Analysis and  SJS.TABLE documentation or try our What-If Analysis DataTable demo.

Support What-If Analysis Goal Seek

The goalSeek method automatically adjusts the value of a specified cell so that a formula in another cell reaches a desired result. This method now accepts an optional options object to control maximumIterations, tolerance, and a per-iteration callback (sync or async) for monitoring progress or stopping early.

Learn more in our Goal Seek documentation or try our What-If Analysis Goal Seek demo.

Import/Export

Support XLTX File Formats

SpreadJS now fully supports the Excel XLTX template file format, allowing users to import .xltx templates as normal workbooks in the browser and export workbooks back to .xltx while preserving template behavior in Excel. This includes new public APIs and Designer support for opening and saving XLTX files for seamless template-based workflows.

Read more in our Excel export docs or try our online Import & Export demo explorer.

Export SparklineEx Types as Images in Excel 

SpreadJS can now export barcode, sparkline, and custom SparklineEx formulas as images to Excel when saveAsView is enabled, so the rendered visuals remain intact even though Excel doesn’t natively support these formulas. The original formulas are still preserved alongside the images.

Read more in our Sparkline export docs.

Data Manager

DataSource Panel Enhancements

SpreadJS Designer’s revamped Data Source panel uses collapsible sections, clearer column tools, and a new Local Data Setup dialog to quickly bind in‑memory JSON/column JSON/CSV/XML data. A new Data tab also provides a read-only TableSheet-style preview so users can verify styles, calculated columns, and schema without leaving the designer. 

The Designer also allows users to customize request headers for remote APIs through a new UI, enabling configuration of authentication tokens and other header values with options for adding, deleting, and updating headers, including a convenient list of commonly used headers.

Learn more in our DataSource documentation.

TableSheet

Support Multi-column Sorting

TableSheet now supports multi-column sorting, letting users combine and sequence sorts across multiple fields with clear visual indicators and intuitive [+]/[-] controls in the filter menu. Developers can enable or disable this behavior per sheet, while grouped, hierarchical, and cross columns respect the defined sort order for more precise, Excel-like data views.

Read more in our Sort and Filter docs or try our TableSheet MultiSort demo.

PivotTable

Automatically Add Excel-like Date Groups 

PivotTables can now automatically group date fields into Excel-like date hierarchies (Years, Quarters, Months, etc.) when added through the Panel.

Read more in our PivotTable Group Date documentation or try our PivotTable Date Group demo.

Added Field Search in Pivot Panel

SpreadJS now adds an Excel-like search box to the Pivot Panel’s field list, making it easy to instantly filter and find pivot source fields. This enhancement streamlines working with large pivot datasets so users can locate and configure fields much faster.

Read more in our Field Search Box documentation or try our Pivot Panel demo.

Collaboration Server

Support Table Sheet and Data Manager

SpreadJS now adds full collaboration support for Table Sheet and the underlying Data Manager, synchronizing all configuration-level operations (sheets, views, relationships, sort/filter/group, etc.) across users while intentionally excluding externally managed datasets so you get real-time, high‑performance coauthoring without compromising external data control. This “configuration collaboration” model ensures consistent document snapshots and undo/redo behavior in multi-user scenarios, even with complex Table Sheet and Data Manager structures.

Learn more in our Collaboration Data Manager documentation or try our Collaboration Server demo.

Support Local Data in Data Manager

TableSheet now supports full collaboration on local data managed by Data Manager, synchronizing edits to records, columns, hierarchies, pinned rows, and schema changes across users while efficiently storing large datasets as fragments. JSON and columnJSON formats are fully collaborative, giving teams real-time, Excel-like coauthoring even when working with complex tree layouts and large local datasets.

Learn more in our Collaboration TableSheet documentation.

DataCharts

Support Hierarchical Category in DataCharts

DataChart now supports hierarchical categories on Cartesian charts, so you can visualize multi-level dimensions like Year→Quarter→Month or Region→Country→City on a single axis with predictable grouping and aggregation. The new nested category encoding API preserves backward compatibility while enabling rich drill-style analysis across supported column, bar, area, line, candlestick, and OHLC chart types.

Read more in our DataChart Category Binding docs or try our DataChart Hierarchical Category demo.

GanttSheet

Improved UX for Building GanttSheet

SpreadJS Designer now includes an enhanced GanttSheet panel that centralizes field mapping, hierarchy configuration, and default task mode into a single, drag‑and‑drop experience—complete with auto-mapping and intelligent inference based on your data schema. This makes it far easier to bind data sources and use GanttSheet for both scheduling and general timeline/date‑range visualizations without hunting through multiple dialogs.

Learn more in our GanttSheet Designer docs.

Table Theme Support in GanttSheet

GanttSheet now fully honors SpreadJS TableTheme styling across its table, time scale, and chart regions, so fonts, colors, backgrounds, alternating rows, and gridlines stay visually consistent with your TableSheet designs.

Learn more in our GanttSheet Table Theme documentation or try our GanttSheet Theme demo.

UI and UX Enhancements

Enhancement	Description	Preview
Automatic Scrollbar Visibility	New "auto" scrollbar option, which intelligently hides scrollbars when content isn't scrollable, creating a cleaner user interface.
Excel-Like Checkboxes	Now offers a modern Excel-style UI with configurable hit-testing and text editing, plus full Excel import/export support.
Disable Mentions in Threaded Comments	Lets you disable @mentions in threaded comments via configuration, so you can keep the comments experience while hiding the mention panel
Adding Shapes via Drag-and-drop	Drawing Mode for adding shapes with a precision crosshair cursor and real-time, translucent outlines, supporting snapping and connector routing.
Curved Connector Shapes	SpreadJS now supports curved connector shapes in addition to straight and elbow.

Framework Support

Angular 21 Support

SpreadJS is now fully tested and confirmed compatible with Angular 21, with our Angular demos updated to Angular v21.2.0 so developers can confidently upgrade their Angular apps without changing any SpreadJS integration code.

Get started with our Angular guide.

NextJS 16 Support

SpreadJS is now fully compatible with Next.js 16, with a simple React integration pattern using client components, next/dynamic (SSR disabled), and updated guidance for Turbopack and addon imports so spreadsheet apps run smoothly in the latest Next.js stack.

Get started with our NextJS guide.

We encourage you to explore these new features and incorporate them into your projects. As always, you can find more details in our documentation and see these capabilities in action in our online demos. This release continues our commitment to making SpreadJS the most comprehensive and high-performance JavaScript spreadsheet solution available.

Happy coding, and we look forward to seeing what you build with SpreadJS v19.1!

Chris Bannon, Product Manager, SpreadJS

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