Testplane

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Introduction

Testplane, previously known as Hermione, is a framework for testing web applications ‘at any scale, any browser and any platform’, in the project’s words. It is developed under the gemini-testing organisation on GitHub and has been used for large web products for years before the rename. It builds on WebdriverIO, so tests use the familiar WebdriverIO browser API.

A distinctive part of Testplane is visual testing. The assertView command captures a screenshot of a page or element and compares it with a stored reference. The README describes several diff modes and a streamlined UI for reviewing and accepting changes, and Testplane includes measures to reduce screenshot flakiness. This makes it a single tool for both functional and visual checks.

For scale, Testplane runs tests in parallel, supports sharding and isolated browser contexts, and can run on a remote browser grid as well as locally. It retries failed tests according to configurable rules, which helps on large suites where some network noise is unavoidable. The project emphasises broad automation-protocol support rather than only the latest Chrome builds.

Developer experience features include an installation wizard, TypeScript support, live test editing with instant feedback, auto-waiting and an advanced HTML reporter (html-reporter plugin) for browsing results and screenshot diffs. A plugin system lets teams extend almost every stage of the run.

In the quality loop, Testplane sits at the end-to-end stage and overlaps the visual regression stage. It is a strong choice for teams that want functional and screenshot tests in one runner and need to run them across many browsers on their own grid.

The source code is at gemini-testing/testplane on GitHub under the MIT licence, with about 834 stars; the most recent commit was on 10 November 2026.

Adopting Testplane works best in steps. Start with a handful of critical journeys running in one browser locally, then add the browsers your users actually use, and only then turn on screenshot assertions for stable pages. Visual checks are most reliable when dynamic content such as dates, ads and animations is hidden or frozen, so plan for that early. Teams that already run Mocha-style tests will find the structure familiar, while teams moving from Hermione should read the migration notes before switching package names in CI.

Features

1. WebdriverIO API: Tests use the WebdriverIO browser API, so existing WebdriverIO knowledge transfers.
2. Visual assertions: assertView captures and compares screenshots of pages or elements against references.
3. Diff review UI: The HTML reporter shows screenshot diffs and lets you accept new references.
4. Parallel runs and sharding: Run many browsers in parallel and split suites across machines.
5. Remote grids: Run on Selenium-compatible grids as well as local browsers.
6. Retries: Configurable retry rules for unstable tests.
7. Isolated browser contexts: Keep tests independent within one browser session.
8. TypeScript and wizard: TypeScript support and a setup wizard for new projects.
9. Live test editing: Change a test and see results quickly while developing.
10. Plugins: A plugin system to hook into the test lifecycle.

Pros

1. Functional and visual in one tool: No need to run a separate screenshot tool next to the functional suite.
2. Proven at scale: Developed for large web products before its open-source rename.
3. Free to use: Open source under the MIT licence, so the core tool costs nothing to use.
4. Actively maintained: The repository had commits as recent as 10 November 2026.

Cons

1. Smaller community: About 800 GitHub stars, so fewer tutorials than for Playwright or Cypress.
2. Grid knowledge needed: Getting the most from Testplane assumes you run or rent a browser grid.
3. WebDriver-based: Some modern features, such as rich network mocking, are easier in CDP-first tools.
4. Docs history: Older material still refers to Hermione, which can confuse searches.

Usage and Links (Example)

Create a project with the wizard:

npm init testplane@latest my-tests

A test with a visual check:

// tests/login.testplane.js
describe("login page", () => {
  it("renders and signs in", async ({ browser }) => {
    await browser.url("/login");
    await browser.assertView("form", "form.login");
    await browser.$("#email").setValue("user@example.com");
    await browser.$("button[type=submit]").click();
    await expect(browser.$("h1")).toHaveText("Welcome");
  });
});

Run and open the report:

npx testplane
npx testplane gui

Practical tips:

1. Keep reference screenshots in Git and review diffs in pull requests.
2. Run visual tests in a fixed container image so fonts and rendering stay stable.
3. Use retries sparingly and track which tests need them.

Resources:

• Testplane website
• GitHub repository

Pricing

Testplane is free and open source under the MIT licence.

Recommended for?

1. Teams that want functional and visual tests in one runner.
2. WebdriverIO users who need a more opinionated framework around it.
3. Organisations with their own browser grid and large cross-browser suites.
4. Not a fit if you prefer Playwright’s CDP-first model or need a very large community.

Conclusion

Testplane is a mature, actively released framework that combines WebdriverIO automation with first-class screenshot testing, parallelism and reporting.

It deserves a look from teams that want visual regression checks alongside functional tests without stitching several tools together.

On CheckOps, Testplane is filed under the End-to-end & functional and Prototype & UX testing stages. Related tools listed here include WebDriverIO, Playwright, CodeceptJS, BackstopJS, Argos and NightWatchJS. Before choosing, compare them on licence, supported languages and platforms, hosting model, and how well each fits your existing CI pipeline. Facts on this page were checked against the official website, documentation and repository on 11 November 2026; statements the vendor makes about its own product are marked as vendor claims.