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Gaussian Elimination

Watch a 4×4 matrix reduce to upper-triangular form one row operation at a time — the algorithm behind every linear solve, factorization, and determinant.

Gaussian Elimination StudioLive

Controls

Step through real Gaussian elimination. Partial pivoting swaps rows to keep the pivot large (cyan) and stable; the multipliers build L while the reduced rows build U.

Presets

▶ Run in Python

Data Inspector

MatrixWell-conditioned
Pivots4
Row swaps0
det(A)661
Invertibleyes
Step0 / 6

Governing equation

Reading this result: Every pivot was already the largest in its column, so no swaps were needed (P = I). The multipliers fill in L, the reduced rows form U, and det(A) = product of U's diagonal = 661.

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How it works

Gaussian elimination with partial pivoting factors a matrix as PA = LU: the permutation P records the row swaps that keep the pivot as large as possible (crucial for numerical stability), the multipliers fill the unit-lower-triangular L, and the reduced rows become the upper-triangular U. Step through each swap and row operation, watch the active pivot highlighted in cyan, and see the determinant emerge as the signed product of U's diagonal. A zero pivot with nothing to swap in signals a singular matrix — no unique factorization, no inverse, det(A) = 0.

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Frequently asked questions

Is this Gaussian elimination LU decomposition tool really free?
Yes. Gaussian Elimination runs entirely in your browser using your device's own compute, so local use is free forever. You only pay Compute Tokens if you scale a job to the cloud.
Do I need to install anything?
No. Everything runs client-side in a modern browser — no downloads, no license, no account required to start.
Can I save or share my simulation?
Create a free account to save projects, and use a shareable embed or minted DOI to publish a live, interactive version anywhere.
How accurate are the results?
The solver uses established numerical methods, but results are for research and educational purposes and should be validated against experiment or professional review before you rely on them.