Excel is not under threat from GridCraft and will not be this year. What GridCraft offers is a fast native engine with a complete function library, an open format path, and an MCP server — a spreadsheet an agent can compute in. If your workbook is inherited, stay where it is.
Side by side
| GridCraft | Excel | |
|---|---|---|
| Maturity | alpha — self-rated ~50% | Four decades of production use |
| Functions | 513 of 523 implemented; 504 verified | The reference implementation |
| Native format | .xlsx read/write; XLSB and ODS import | .xlsx, .xlsb, .xls, legacy variants |
| PivotTables | Not yet | Core, heavily used |
| Get & Transform / Power Query | Absent | Mature |
| Very large workbooks | Listed as outstanding work | Optimised, with a documented model size limit |
| Recalculation | Dependency graph, dynamic arrays, single-threaded recalc for now | Multi-threaded, decades of edge cases |
| Collaboration | None | Real-time co-authoring |
| Automation | MCP server, CLI, JSON control channel | VBA, Office Scripts, add-ins, Power Automate |
| Platforms | Windows, macOS, Linux, BSD, web | Windows, macOS, web |
| Price | Free, MIT or Apache-2.0 | Subscription |
Where GridCraft wins
It exists on Linux. Excel does not. For a Linux workstation, a native spreadsheet with Excel-compatible formulas and .xlsx output is a real gap filled.
The engine is separable. The formula engine, the model and the UI are distinct crates with enforced layering. You can drive a workbook from a script or an agent without opening a window — which is how SELENE-scale automation becomes possible in a spreadsheet context.
No licence, no telemetry, no account. For a company that cannot put a file in a cloud tenant, that changes what is possible.
Speed. A Rust binary recalculating a mid-sized model feels different from a suite loading its add-ins.
Where Excel wins, and it is not close
PivotTables. Listed as pending. Most business spreadsheets are not formula grids — they are pivots on top of a data model, refreshed weekly, emailed to a committee.
Power Query. Absent. The whole modern Excel workflow of pulling, cleaning and reshaping data is not in GridCraft today.
Recalculation fidelity at scale. GridCraft's roadmap cites large workbooks and multi-threaded recalc as outstanding. A spreadsheet that is slow, or worse, quietly different, is a spreadsheet you cannot trust with a number that matters.
The files you inherit. .xlsx round-trip on real-world files is the project's own top-ranked remaining cost.
The test that settles it in five minutes
Open a workbook you know the answer to — not a trivial one, something with lookups, dates and a nested IF. Force a full recalc in GridCraft. Compare the totals against Excel. If they match to the cent, you have a tool. If they do not, you have a promising alpha.
Do that test before you convert anything you depend on, and keep the original file until it passes twice.
Frequently asked
Does GridCraft support PivotTables?
Not yet — they are named in the roadmap as pending, alongside Get & Transform, the data model and collaboration.
How many Excel functions does GridCraft have?
513 of 523 implemented, with 504 verified as computing correctly (96.4%), measured in the project's own function-parity document.
Is GridCraft a replacement for Excel?
For spreadsheets you author yourself, plausibly. For inherited workbooks, no: the project scores itself about 50% ready and ranks real-world file fidelity as its largest remaining cost.
Sources: GridCraft repository (README, ROADMAP.md, docs/function-parity.md, docs/gaps.md); Microsoft Excel documentation. Read 18 October 2026.