PHPUnit is the standard PHP testing framework: class-based, xUnit conventions, everywhere. Pest is a layer on top of it with a function-based syntax, an expectations API, and extras like architecture testing. Because Pest uses the PHPUnit engine underneath, the choice is about how you write and organize tests, not about capability or speed. Laravel supports both out of the box.

PHPUnit vs Pest at a glance

PHPUnit: class-based and ubiquitous

A PHPUnit test is a class extending the framework TestCase, with methods named test* or annotated as tests. It is verbose, but every PHP developer and every CI system already knows it, IDE support is complete, and there is a decade of examples for any scenario. For a team that lives in PHPUnit, there is no forced reason to move.

Pest: functions and expectations

Pest replaces the class with top-level it() and test() functions and the assert*() calls with a chainable expect() API. Datasets parametrize a test without a data provider method, higher-order expectations chain naturally, and arch() lets you assert rules about your own code (no debug helpers in production, controllers do not depend on models directly). It reads well and cuts boilerplate.

The same Laravel feature test, both ways

// PHPUnit
public function test_it_lists_the_user_orders(): void
{
    $user = User::factory()->has(Order::factory()->count(2))->create();

    $this->actingAs($user)
        ->getJson('/api/v1/orders')
        ->assertOk()
        ->assertJsonCount(2, 'data');
}

// Pest
it('lists the user orders', function () {
    $user = User::factory()->has(Order::factory()->count(2))->create();

    $this->actingAs($user)
        ->getJson('/api/v1/orders')
        ->assertOk()
        ->assertJsonCount(2, 'data');
});

Migrating PHPUnit to Pest

They coexist in the same suite: Pest runs your existing PHPUnit classes unchanged, so you can adopt it for new tests and convert old ones gradually, or not at all. There is also a conversion tool that rewrites the common patterns. There is no big-bang migration required.

What actually matters

The framework is a small factor next to whether you have tests at all, whether they cover the risky parts, and whether they run fast enough that people run them. A well-tested app in PHPUnit beats a lightly-tested one in Pest every time. Pick the syntax your team will enjoy writing, because that is what drives coverage.

PHPUnit and Pest are the same engine with different ergonomics. PHPUnit is the safe, universal default; Pest trades a little familiarity for less boilerplate and architecture testing. Either is fine. What matters is that the suite exists, covers the risky code, and runs fast enough that the team keeps running it.