--- id: selenium-grid title: "Selenium Grid (experimental)" --- ## Introduction Playwright can connect to [Selenium Grid Hub](https://www.selenium.dev/documentation/grid/) that runs Selenium 4 to launch **Google Chrome** or **Microsoft Edge** browser, instead of running browser on the local machine. Note this feature is **experimental** and is prioritized accordingly. :::warning There is a risk of Playwright integration with Selenium Grid Hub breaking in the future. Make sure you weight risks against benefits before using it.
More details Internally, Playwright connects to the browser using [Chrome DevTools Protocol](https://chromedevtools.github.io/devtools-protocol/) websocket. Selenium 4 currently exposes this capability. However, this [might not be the case in the future](https://github.com/SeleniumHQ/selenium/issues/11590#issuecomment-1436113950). If Selenium drops this capability, Playwright will stop working with it.
::: Before connecting Playwright to your Selenium Grid, make sure that grid works with [Selenium WebDriver](https://www.selenium.dev/documentation/webdriver/). For example, run [one of the examples](https://github.com/SeleniumHQ/selenium/tree/trunk/javascript/node/selenium-webdriver/example) and pass `SELENIUM_REMOTE_URL` environment variable. If webdriver example does not work, look for any errors at your Selenium hub/node/standalone output and search [Selenium issues](https://github.com/SeleniumHQ/selenium/issues) for a possible solution. ## Starting Selenium Grid If you run distributed Selenium Grid, Playwright needs selenium nodes to be registered with an accessible address, so that it could connect to the browsers. To make sure it works as expected, set `SE_NODE_GRID_URL` environment variable pointing to the hub when running selenium nodes. ```bash # Start selenium node SE_NODE_GRID_URL="http://:4444" java -jar selenium-server-.jar node ``` ## Connecting Playwright to Selenium Grid To connect Playwright to **Selenium Grid 4**, set `SELENIUM_REMOTE_URL` environment variable pointing to your Selenium Grid Hub. Note that this only works for Google Chrome and Microsoft Edge. ```bash js SELENIUM_REMOTE_URL=http://:4444 npx playwright test ``` ```bash python SELENIUM_REMOTE_URL=http://:4444 pytest --browser chromium ``` ```bash java SELENIUM_REMOTE_URL=http://:4444 mvn test ``` ```bash csharp SELENIUM_REMOTE_URL=http://:4444 dotnet test ``` You don't have to change your code, just use your testing harness or [`method: BrowserType.launch`] as usual. ### Passing additional capabilities If your grid requires additional capabilities to be set (for example, you use an external service), you can set `SELENIUM_REMOTE_CAPABILITIES` environment variable to provide JSON-serialized capabilities. ```bash js SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_CAPABILITIES="{'mygrid:options':{os:'windows',username:'John',password:'secure'}}" npx playwright test ``` ```bash python SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_CAPABILITIES="{'mygrid:options':{os:'windows',username:'John',password:'secure'}}" pytest --browser chromium ``` ```bash java SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_CAPABILITIES="{'mygrid:options':{os:'windows',username:'John',password:'secure'}}" mvn test ``` ```bash csharp SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_CAPABILITIES="{'mygrid:options':{os:'windows',username:'John',password:'secure'}}" dotnet test ``` ### Passing additional headers If your grid requires additional headers to be set (for example, you should provide authorization token to use browsers in your cloud), you can set `SELENIUM_REMOTE_HEADERS` environment variable to provide JSON-serialized headers. ```bash js SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_HEADERS="{'Authorization':'Basic b64enc'}" npx playwright test ``` ```bash python SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_HEADERS="{'Authorization':'Basic b64enc'}" pytest --browser chromium ``` ```bash java SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_HEADERS="{'Authorization':'Basic b64enc'}" mvn test ``` ```bash csharp SELENIUM_REMOTE_URL=http://:4444 SELENIUM_REMOTE_HEADERS="{'Authorization':'Basic b64enc'}" dotnet test ``` ### Detailed logs Run with `DEBUG=pw:browser*` environment variable to see how Playwright is connecting to Selenium Grid. ```bash js DEBUG=pw:browser* SELENIUM_REMOTE_URL=http://internal.grid:4444 npx playwright test ``` ```bash python DEBUG=pw:browser* SELENIUM_REMOTE_URL=http://internal.grid:4444 pytest --browser chromium ``` ```bash java DEBUG=pw:browser* SELENIUM_REMOTE_URL=http://internal.grid:4444 mvn test ``` ```bash csharp DEBUG=pw:browser* SELENIUM_REMOTE_URL=http://internal.grid:4444 dotnet test ``` If you file an issue, please include this log. ## Using Selenium Docker One easy way to use Selenium Grid is to run official docker containers. Read more in [selenium docker images](https://github.com/SeleniumHQ/docker-selenium) documentation. For image tagging convention, [read more](https://github.com/SeleniumHQ/docker-selenium/wiki/Tagging-Convention#selenium-grid-4x-and-above). ### Standalone mode Here is an example of running selenium standalone and connecting Playwright to it. Note that hub and node are on the same `localhost`, and we pass `SE_NODE_GRID_URL` environment variable pointing to it. First start Selenium. ```bash docker run -d -p 4444:4444 --shm-size="2g" -e SE_NODE_GRID_URL="http://localhost:4444" selenium/standalone-chromium:latest ``` Then run Playwright. ```bash js SELENIUM_REMOTE_URL=http://localhost:4444 npx playwright test ``` ```bash python SELENIUM_REMOTE_URL=http://localhost:4444 pytest --browser chromium ``` ```bash java SELENIUM_REMOTE_URL=http://localhost:4444 mvn test ``` ```bash csharp SELENIUM_REMOTE_URL=http://localhost:4444 dotnet test ``` ### Hub and nodes mode Here is an example of running selenium hub and a single selenium node, and connecting Playwright to the hub. Note that hub and node have different IPs, and we pass `SE_NODE_GRID_URL` environment variable pointing to the hub when starting node containers. First start the hub container and one or more node containers. ```bash docker run -d -p 4442-4444:4442-4444 --name selenium-hub selenium/hub:4.25.0 docker run -d -p 5555:5555 \ --shm-size="2g" \ -e SE_EVENT_BUS_HOST= \ -e SE_EVENT_BUS_PUBLISH_PORT=4442 \ -e SE_EVENT_BUS_SUBSCRIBE_PORT=4443 \ -e SE_NODE_GRID_URL="http://:4444" selenium/node-chromium:4.25.0 ``` Then run Playwright. ```bash js SELENIUM_REMOTE_URL=http://:4444 npx playwright test ``` ```bash python SELENIUM_REMOTE_URL=http://:4444 pytest --browser chromium ``` ```bash java SELENIUM_REMOTE_URL=http://:4444 mvn test ``` ```bash csharp SELENIUM_REMOTE_URL=http://:4444 dotnet test ``` ## Selenium 3 Internally, Playwright connects to the browser using [Chrome DevTools Protocol](https://chromedevtools.github.io/devtools-protocol/) websocket. Selenium 4 exposes this capability, while Selenium 3 does not. This means that Selenium 3 is supported in a best-effort manner, where Playwright tries to connect to the grid node directly. Grid nodes must be directly accessible from the machine that runs Playwright.