Deterministic by design

Your spreadsheet recalculates when you say so.

Every value traces to its source.

Every output is fingerprinted.

No silent recalc. No ambient state. No surprises between opens.

Same inputs + same formulas = same hash. Always.

The problem with spreadsheet engines

Excel recalculates silently. Values change between opens. You can't prove what ran.

You open a file on Monday. The totals look right. You open the same file on Friday. The totals are different.

What changed? You don't know. Excel doesn't tell you. It doesn't even know it happened.

You can't verify what changed. You can't prove what didn't.

If your calculation isn't deterministic, your output isn't evidence. It's an opinion.

You control when values update. Not the spreadsheet. Not a timer. Not a dependency you didn't ask for.

No silent recalc. No ambient state. No volatile functions injecting nondeterminism into your model.

When you press recalculate, the engine evaluates every formula in dependency order and stops. The result is the same every time for the same inputs.

Every sheet produces a fingerprint: a hash of its inputs, formulas, and outputs. Same inputs + same formulas = same hash.

Change one cell and the fingerprint changes. Revert it and the fingerprint returns. It's deterministic all the way down.

Use vgrid sheet verify to check any sheet against a known fingerprint. In CI, in audits, in handoffs.

Every cell knows what feeds it. Click a cell and see its precedents — across sheets, across ranges.

No manual tracing. No guessing which tab that reference points to. The graph is always current, always complete.

When a value changes, you see exactly what it affects. Not approximately. Exactly.

Prove that the output matches the inputs. One command, one hash, one answer.

Attach a fingerprint to your filing. Verifiable by anyone with the CLI.

Hand off a model with proof that it produces the numbers you claim.

Gate deployments on spreadsheet verification. Same rigor as code.

	Excel / Sheets	VisiGrid
Recalculation	Automatic, silent. Values can change between opens.	Manual. You control when. Same inputs = same outputs.
Auditability	No built-in verification. Track Changes is manual and lossy.	Fingerprint any sheet. Verify with one command.
Custom code	VBA, Python, Apps Script. Stateful, side-effectful, unverifiable.	Lua sandbox. Pure functions. Included in the fingerprint.

Deterministic calculation, fingerprinting, and verification are included in VisiGrid Free.