We’ve just released HyperFormula 3.1.1, a patch release focused on improving reliability for developers working with advanced spreadsheet models. This update addresses two important issues and adds clarity to our Excel compatibility roadmap. While it’s not a major release, it removes roadblocks for developers using named expressions and working with dynamic sheet structures.

More Flexible Lazy Evaluation with Safe Overwrites

One of the standout features of HyperFormula is its lazy computation engine. Instead of recalculating everything right away, HyperFormula delays computations until the results are actually needed. 

This approach delivers multiple performance benefits:

• It helps spread out expensive operations, preventing performance slowdowns during bulk updates.
• It allows HyperFormula to skip unnecessary calculations, saving time and resources when a result isn’t ultimately required.
• It ensures better responsiveness in applications, even when working with thousands of formulas or dynamic data.

In this release, we improved how lazy evaluation handles edge cases where overwriting a not-yet-computed cell could trigger a confusing error (#1194); for example, when adding a named expression. With version 3.1.1, you can safely overwrite any cell at any time, regardless of whether its value has been computed yet. The lazy evaluation logic now behaves more predictably, making your spreadsheet logic easier to control.

Automatic Dependency Handling Across Sheets

HyperFormula 3.1.1 also fixes an issue where dependent cells were not recalculated correctly after structural operations like adding, removing, or renaming sheets (#1116). In affected cases, formulas referencing other sheets could result in stale values or #REF! errors due to missing dependency updates.

The most common scenario was adding multiple interdependent sheets. Previously, if a sheet referenced another sheet that hadn’t been added yet, it would trigger a #REF! error. To work around this, you had to:

• Ensure sheets were added in a specific topological order, or
• Use the rebuildAndRecalculate() method, which forces a full graph rebuild but introduces performance overhead 

With this release, HyperFormula now resolves cross-sheet dependencies automatically during structural changes. Your sheets can be added, removed, or renamed in any order, and the dependency graph is updated accordingly. All affected formulas are properly recalculated without requiring manual intervention.

This change eliminates the need for initialization-time workarounds, making the engine more robust in dynamic or programmatic sheet management scenarios.

Excel Compatibility: Where We Stand

We recently conducted an internal analysis to understand how many Excel functions are currently supported in HyperFormula and identify any missing ones. This helps us, and our users, get a clear view of where we stand in terms of Excel compatibility.

The results are now published in our Compatibility with Microsoft Excel guide. This summary will help guide our roadmap decisions moving forward. Based on the findings, we’re planning to add several new functions in Q1 and Q2 of 2026 to improve compatibility even further.

If you’re building tools that rely on Excel-like functionality, this resource will help you evaluate how HyperFormula fits your needs today, and what’s coming next.

Coming Soon 

In the next release of HyperFormula, we’re shifting focus to new features. We plan to expand the function library with three new Excel-compatible functions:

• IRR (Internal Rate of Return for irregular cash flows)
• VALUE (converts a text string to a number)
• N (returns a value as a number)
  

We’re also finalizing support for Iterative Calculation, which enables controlled circular references, making it helpful in solving equations through repeated recalculation until a specific condition is met. Additionally, we’re preparing a developer guide on using AI tools with HyperFormula, aimed at simplifying the process of generating custom functions using AI.

We’re Hiring: Join the HyperFormula Team

If you’re a developer with a knack for algorithms and love working on graph problems and numerical methods, we want to hear from you!

We’re looking for someone to help us push HyperFormula even further. It’s a chance to work on a high-performance formula engine written in TypeScript, used in complex, spreadsheet-driven applications around the world.

See full job description and apply here.

Release Notes

Fixed

• Fixed an issue where cells were not recalculated after adding, removing and renaming sheets. #1116
• Fixed an issue where overwriting a non-computed cell caused the Value of the formula cell is not computed error. #1194