A faster, simpler way to drive browsers supporting the Chrome DevTools Protocol.

About chromedp

Package chromedp is a faster, simpler way to drive browsers supporting the Chrome DevTools Protocol in Go without external dependencies (like Selenium or PhantomJS).

Installing

Install in the usual Go way:

go get -u github.com/chromedp/chromedp

Examples

Refer to the GoDoc page for the documentation and examples. Additionally, the examples repository contains more complex examples.

Frequently Asked Questions

I can’t see any Chrome browser window

By default, Chrome is run in headless mode. See DefaultExecAllocatorOptions, and an example to override the default options.

I’m seeing “context canceled” errors

When the connection to the browser is lost, chromedp cancels the context, and it may result in this error. This occurs, for example, if the browser is closed manually, or if the browser process has been killed or otherwise terminated.

Chrome exits as soon as my Go program finishes

On Linux, chromedp is configured to avoid leaking resources by force-killing any started Chrome child processes. If you need to launch a long-running Chrome instance, manually start Chrome and connect using RemoteAllocator.

Executing an action without Run results in “invalid context”

By default, a chromedp context does not have an executor, however one can be specified manually if necessary; see issue #326 for an example.

I can’t use an Action with Run because it returns many values

Wrap it with an ActionFunc:

chromedp.Run(ctx, chromedp.ActionFunc(func(ctx context.Context) error {
	_, err := domain.SomeAction().Do(ctx)
	return err
}))

I want to use chromedp on a headless environment

The simplest way is to run the Go program that uses chromedp inside the chromedp/headless-shell image. That image contains headless-shell, a smaller headless build of Chrome, which chromedp is able to find out of the box.

Resources

• chromedp: A New Way to Drive the Web - GopherCon SG 2017 talk
• Chrome DevTools Protocol - Chrome DevTools Protocol Domain documentation
• chromedp examples - various chromedp examples
• github.com/chromedp/cdproto - GoDoc listing for the CDP domains used by chromedp
• github.com/chromedp/cdproto-gen - tool used to generate cdproto
• github.com/chromedp/chromedp-proxy - a simple CDP proxy for logging CDP clients and browsers