Generate Pairwise (All-Pairs) Test Cases

List your parameters and their values and get a compact set of test cases that covers every pair of values — a fraction of the full combination count. Deterministic and private.

Turn a parameter model into a compact test matrix

Testing every combination of every option quickly explodes: three parameters with 3, 3, and 2 values already make 18 full combinations, and adding a fourth parameter multiplies that again. Pairwise (all-pairs) testing exploits the fact that most defects are triggered by a single value or by the interaction of just two values. This tool generates a small set of test cases in which every value of every parameter is paired at least once with every value of every other parameter — so you keep the coverage that finds interaction bugs while dropping most of the redundant rows.

List one parameter per line as Name: value1, value2, …. Blank lines and lines that start with # are ignored, so you can annotate your model. The generator is fully deterministic — the same model always produces the same cases — and runs entirely in your browser, so nothing you type is uploaded.

Choose Markdown for a table you can paste into a pull request or wiki, CSV to import into a spreadsheet or test-management tool, JSON to feed a script or data-driven test runner, or ASCII for a plain box-drawn grid. Leave Number each case on to prepend a # column, or turn it off for a clean copy.

Worked example

Model:

Browser: Chrome, Firefox, Safari
OS: Windows, macOS, Linux
Theme: Light, Dark

The full Cartesian product is 3 × 3 × 2 = 18 combinations. Pairwise coverage needs only 9:

| # | Browser | OS      | Theme |
| --- | ------- | ------- | ----- |
| 1 | Chrome  | Windows | Light |
| 2 | Chrome  | macOS   | Dark  |
| 3 | Chrome  | Linux   | Light |
| 4 | Firefox | Windows | Dark  |
| 5 | Firefox | macOS   | Light |
| 6 | Firefox | Linux   | Dark  |
| 7 | Safari  | Windows | Light |
| 8 | Safari  | macOS   | Dark  |
| 9 | Safari  | Linux   | Light |

Every Browser/OS, Browser/Theme, and OS/Theme pair appears in at least one row — for example Firefox is tested with Windows, macOS, and Linux, and with both Light and Dark.

FAQ

What is pairwise (all-pairs) testing?

It is a test-design technique that generates the smallest practical set of cases so that every pair of values from any two parameters is exercised at least once. Empirically most bugs depend on one factor or the interaction of two, so all-pairs coverage catches the large majority of interaction defects for a tiny fraction of the exhaustive cost.

How do I write the parameter model?

One parameter per line as Name: value1, value2, …. The part before the first colon is the parameter name (it may itself contain commas or spaces); everything after is a comma-separated list of values. Blank lines and lines beginning with # are ignored, so # smoke test is a comment. You need at least two parameters, because a pair needs two.

Will I get the same cases every time?

Yes. The generator uses a deterministic greedy algorithm — it seeds each new case from the first still-uncovered pair, then fills the remaining parameters with the value that covers the most still-missing pairs, breaking ties by order. The same model always yields byte-for-byte identical output, so you can commit the result and diff it.

Why did I not get the absolute minimum number of cases?

Finding the provably smallest all-pairs set is NP-hard. This tool uses a fast greedy heuristic that produces a near-minimal set — usually within a case or two of optimal for typical models — while guaranteeing full pair coverage. It favours speed and determinism over squeezing out the last row.

Can I add constraints like "if OS is Linux, Browser cannot be Safari"?

Not yet — this tool generates unconstrained pairwise (2-way) coverage only. It does not support constraints/exclusions, seeded mandatory rows, or higher-strength t-way (3-way, 4-way) coverage. After generating, delete any rows that violate a real constraint, or split your model so invalid pairs never occur.

Limits and edge cases

Pairwise only. Coverage is strictly 2-way (all-pairs). There is no 3-way/4-way (t-way) mode and no way to guarantee a specific triple of values appears together.
No constraints or exclusions. Every combination is treated as valid; the generator will happily pair values that your system forbids. Prune impossible rows afterward.
At least two parameters. A single parameter has no pairs to cover, so the tool asks for two or more.
Size caps. Up to 20 parameters and 30 values per parameter. Values within one parameter must be unique, and parameter names must not repeat — duplicates are rejected with a clear message.
Near-minimal, not provably minimal. The greedy result is compact but may include a case or two more than a theoretical optimum.

Developer & Automation Access

Run it from the terminal

Same engine as this page, headless — via the gizza CLI:

gizza tool pairwise-test-generator "Browser: Chrome, Firefox, Safari
OS: Windows, macOS, Linux
Theme: Light, Dark"

New to the CLI? Get gizza →

Open it by URL

Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:

https://gizza.ai/tools/pairwise-test-generator/?parameters=Browser%3A%20Chrome%2C%20Firefox%2C%20Safari%0AOS%3A%20Windows%2C%20macOS%2C%20Linux%0ATheme%3A%20Light%2C%20Dark&output_format=markdown&include_index=true

Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.