what's the best browser automation platform for automating websites at scale?

No single winner. The sources agree that these tools solve different problems, so "best" depends on the workload. The main layers are the automation framework (writes the logic), the managed browser infrastructure (runs the browsers), and the AI layer (optional, adds LLM-driven control).

Playwright is the default framework. It's Microsoft's cross-browser framework (Chromium, Firefox, WebKit), and it's described as the default for teams starting fresh in 2026, covering both testing and scraping. Its limitation is that you maintain the selectors and workflow code yourself. Selenium remains common in legacy enterprise setups.

Managed infrastructure is the main choice at scale. These platforms host the browsers your Playwright, Puppeteer or Selenium scripts drive:

• Browserbase: Suits persistent, observable sessions at scale, and pairs with Stagehand, its open-source AI SDK for TypeScript. One comparison calls Browserbase plus Stagehand the strongest package for developer ergonomics without managing servers. Downsides: usage-based costs, no proxies included, and the core platform is proprietary.
• Bright Data Browser API: Managed, auto-scaling Chrome with built-in proxy rotation, CAPTCHA solving and fingerprint randomization. It connects over the Chrome DevTools Protocol, so existing scripts need only an endpoint change. It's positioned for heavily protected sites and enterprise scale, and is the most expensive option in one cost comparison.
• Steel: Open source and self-hostable. One writer calls it the best self-hosted browser API, and says it's hard to justify paying a monthly fee if you're comfortable with Docker on a VPS.
• Browserless and Apify: Chrome-as-a-service and a scheduling/orchestration platform, respectively. Self-hosting is cheapest until sites block you. One source says Playwright on a small VPS can cost a few euros a month and handle the same volume. The trade-off is that you handle scaling, proxies and anti-bot problems yourself.

AI-native options are newer and complementary. Browser Use (autonomous Python agents), Stagehand (AI-assisted TypeScript SDK), Skyvern (workflow platform for changing portals) and Playwright MCP (browser tools for existing agents) add LLM reasoning. The trade-off is that AI steps cost more and run slower than a known selector, so they fit changing, multi-step interfaces better than stable, high-volume paths.

Not every job needs a browser. For plain data extraction, single-API tools like Firecrawl (pass a URL, get clean data) avoid session management and latency. Use a full browser when you need stateful interaction such as logins, multi-step flows, screenshots or session recording.

Rough guide from the sources:

• Stable, known flows: Playwright, with self-hosting or Steel.
• Scaling without managing infrastructure: Browserbase.
• Aggressive anti-bot protection: Bright Data.
• Changing interfaces or agent workflows: Stagehand, Browser Use or Skyvern.
• Caveat: Many of these comparisons are published by vendors in this space (Scrapfly, ScrapeGraphAI, Firecrawl, Skyvern, Bright Data), so their rankings lean toward their own products. Prices also vary by plan and change often, so check current pricing. Whatever you choose, follow each site's terms and privacy laws.