How to automate a web browser

Automating a web browser means driving it with code instead of by hand. For testing, the standard browser automation tools are Selenium and Playwright. For automating work across many separate identities — multiple accounts, ad verification, scraping — you also need each session to look like a different real device, which is where an anti-detect browser with an automation API comes in. Here's how the pieces fit.

What does "automate a web browser" actually mean?

Instead of a person clicking buttons, a script tells the browser what to do: open a URL, fill a form, click, scroll, read text, take a screenshot. The browser exposes a control interface (WebDriver, or the Chrome DevTools Protocol), and a library speaks to it. That's the whole idea behind every browser automation tool.

Selenium vs Playwright: the two standard tools

Selenium is the long-established, language-agnostic framework built on the WebDriver standard. It has the biggest ecosystem, supports almost every language, and is the default for cross-browser testing and Selenium test automation at scale (Selenium Grid). If you've searched for "selenium for software testing," "selenium test automation framework," or "selenium ui testing," this is the tool.

Playwright is a newer Microsoft framework with one modern API across Chromium, Firefox, and WebKit. It auto-waits for elements, is fast, and is reliable out of the box — often quicker to write than Selenium. As a Playwright test tool it's excellent for end-to-end testing of a single app.

	Selenium	Playwright
Best for	Cross-browser test automation, huge grids	Modern E2E testing, speed
Languages	Java, Python, C#, JS, Ruby, more	JS/TS, Python, Java, .NET
Standard	W3C WebDriver	CDP / WebKit protocols
Learning curve	Steeper, more setup	Gentler, batteries included

Where testing tools stop: many identities

Selenium and Playwright are built for testing one app. They automate a normal browser that exposes the same fingerprint on every run. The moment you automate work across many separate accounts — posting from ten profiles, verifying ads in different regions, scraping without being rate-limited — that shared fingerprint and IP link everything together, and platforms flag it. Plain automation isn't enough; you need automation plus identity isolation.

Automating isolated profiles with Alias

Alias Browser is an anti-detect browser you can drive programmatically. Each profile has its own consistent fingerprint, isolated storage, and a dedicated proxy or VPN — and you control them with code:

• REST API — create, launch, and stop profiles; list and manage them from any language.
• MCP server — expose those same actions to AI agents over the Model Context Protocol, so an agent can spin up and operate isolated browsers.
• Attach your existing scripts — because launched profiles expose a debugging endpoint, you can point Selenium or Playwright at a running Alias profile and reuse the automation code you already have, now inside a believable, isolated identity.

So the honest split is: use Selenium/Playwright when you're testing a website; add Alias when you need to automate real work across many accounts without them being linked.