Browser Use vs Selenium

Browser Use

The hosted cloud accepts x402 top-ups in USDC on Base with no account or API key, and publishes prices, rate limits and three OpenAPI documents. The privacy policy says inputs are used to train Browser Use's models, API keys have no documented scopes, and no prompt-injection guidance was found in the docs.

Selenium

Selenium is stable, Apache-2.0 software on 4.51.0 with bindings in five languages, CI passing on trunk, an llms.txt and an agent guide added in September 2026. It has no MCP server of its own, Selenium Manager sends usage statistics by default, and Grid accepts unauthenticated sessions unless a username and password are set.

Browser Use

1. Send the key as X-Browser-Use-API-Key with no Bearer prefix. A Bearer header returns 401
2. Stop browsers with PATCH /api/v4/browsers/{id} and {"action":"stop"}. Closing CDP or the SDK client leaves the browser billing
3. Poll GET /runs/{id}/status, not the full run, and wait for the returned Retry-After on 429, which can be 300 seconds at the edge
4. Before resubmitting after a timeout, read the existing run's status. The server keeps running and may already have submitted a form
5. With a wallet and no key, call x402.api.browser-use.com on /api/v2 or /api/v3 routes. A task stops with INSUFFICIENT_CREDITS if credit runs out mid-run

Selenium

1. Install with pip install selenium (Python 3.10 or later) and let Selenium Manager fetch drivers. Do not set driver paths
2. Use WebDriverWait with expected conditions, never fixed sleeps, and do not mix implicit and explicit waits
3. Set SE_AVOID_STATS=true to stop Selenium Manager sending usage statistics
4. Point coding agents at https://www.selenium.dev/llms.txt. Most Selenium 2 and 3 era examples use removed APIs
5. Set --username and --password before exposing a Grid beyond localhost. Check http://localhost:4444/status before creating sessions