Pest
Pest is a PHP testing framework for developers and AI agents, available free as a Composer development dependency in a PHP project.
What Pest is
Pest is a PHP testing framework for developers and AI agents, available free as a Composer development dependency in a PHP project. Pest 5 requires PHP 8.4 or later. Its features include parallel execution, coverage, mutation and snapshot testing, profiling, architectural testing, browser testing, and optional plugins. The Browser plugin uses Playwright for tests that interact with pages, such as clicking buttons or filling forms. The Agent plugin lets coding agents run one-off checks against an application using Pest tests, and can drive a real browser when the Browser plugin is installed. Pest Evals combines regular Pest tests with AI-powered scorers to assess LLM responses; its documentation describes a scorer for checking an agent’s resistance to prompt injection. The Tia Engine reruns tests affected by recent changes and requires PCOV or Xdebug as a coverage driver. Pest 5 includes first-party PHPStan and Rector plugins, while team-maintained plugins include Faker, Laravel, and Livewire. JetBrains maintains the PhpStorm plugin, included by default since version 2023.3. Pest supports parameterized cases but does not include built-in mocks. Its maintainers say they do not guarantee a fixed bug resolution time or a fix for every issue; outdated-version bug fixes are available for 12 months after the latest version’s release.
Good
- Available free as a Composer development dependency.
- Supports parallel execution and multiple testing methods.
- Browser plugin runs Playwright-based page interactions.
- Evals can apply AI-powered scorers.
- Supports parameterized cases.
Watch out
- Pest 5 requires PHP 8.4 or later.
- Tia Engine requires PCOV or Xdebug.
- Built-in mocks are not included.
- No fixed bug resolution time is promised.
Who it suits
Pest suits PHP developers and coding agents, from small personal projects to enterprise applications. Its browser and evaluation tools may be useful to teams testing web interactions or LLM responses.
Verdict
Pest combines conventional PHP testing with browser checks and LLM evaluations. Check the PHP version requirement and coverage-driver dependency, and note that bug fixes are not guaranteed on a fixed timeline.
Plans and prices
From Pest's own pricing page, checked 5 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Pest | Free | Open-source PHP testing framework · Requires PHP 8.4+ for Pest 5 |
The facts
Each one read from Pest's own pages, with the date it was checked.
What it does
- AI agent checks
- The Agent plugin lets coding agents run isolated checks against a live app and save screenshots as proof.checked 5 Oct 2026
- AI evaluations
- Pest Evals can combine deterministic checks with AI-powered scorers to assess LLM output from a test suite.checked 5 Oct 2026
- Editor integration
- JetBrains maintains the Pest plugin for PhpStorm, where it has been included by default since version 2023.3.checked 5 Oct 2026
- Framework integrations
- The Pest 5 Tia Engine documentation says it detects Laravel, Symfony, Livewire, Inertia, and browser assets automatically via Composer.checked 5 Oct 2026
- Install
- Pest is installed in a PHP project as a Composer development dependency.checked 5 Oct 2026
- Integrations
- Pest's team-maintained plugins include Faker, Laravel, and Livewire.checked 5 Oct 2026
- Intended users
- The maker describes Pest as a testing framework for PHP developers and AI agents.checked 5 Oct 2026
- LLM evaluations
- Evals use ordinary Pest tests and can apply AI-powered scorers to responses.checked 5 Oct 2026
- PHP requirement
- Pest 5 requires PHP 8.4 or greater and is built on PHPUnit 13.checked 5 Oct 2026
- PHP tooling
- Pest 5 includes first-party plugins for PHPStan and Rector, and its release page describes time-balanced sharding for CI machines.checked 5 Oct 2026
- Purpose
- Pest is a PHP testing framework for developers and AI agents.checked 5 Oct 2026
- Security
- The homepage shows a security architecture testing preset, but the opened maker pages did not state a security certification or compliance standard.checked 5 Oct 2026
- Security testing
- Pest's Evals documentation describes a toBeSafe() scorer for checking whether an AI agent resists prompt injection.checked 5 Oct 2026
- Support
- Pest's maintainers say they cannot guarantee a fixed bug resolution time or a fix for every issue; bug fixes for outdated versions are available for 12 months after the latest version's release.checked 5 Oct 2026
- Support policy
- Pest says bug fixes for outdated major versions are available for 12 months after the latest version's release, with no fixed resolution time or guaranteed fix for every issue.checked 5 Oct 2026
- Test features
- Pest includes parallel execution, coverage, mutation testing, and snapshots.checked 5 Oct 2026
- Test impact analysis
- The Tia Engine reruns tests affected by recent changes and requires PCOV or Xdebug as a code coverage driver.checked 5 Oct 2026
- Testing features
- Pest lists parallel execution, browser testing, profiling, architectural testing, coverage, mutation testing, and optional plugins among its features.checked 5 Oct 2026
- Who it is for
- Pest says it is suitable for small personal projects and large-scale enterprise applications.checked 5 Oct 2026
Where it runs
- Browser testing
- The Browser plugin uses Playwright to run browser tests that can interact with pages, including clicking buttons and filling forms.checked 5 Oct 2026
The company
- Maker
- The site describes Pest as a PestPHP project by Nuno Maduro.checked 5 Oct 2026
