Kernel alternatives
The highest-scoring alternative to Kernel is Steel at 90/100 on the AgentReady, against 89/100 for Kernel.
All scored in Browser Automation.
What Steel does that Kernel does not
Steel passes no mandatory sales call, agent-compatible signup flow, fast time to first request, copyable quickstart, and Kernel fails them. That is the whole of the gap between the two scores, so if none of those matter to your agent the ranking above overstates the difference.
Why people look for an alternative
Kernel fails authentication documented, no mandatory sales call, agent-compatible signup flow, fast time to first request, copyable quickstart, idempotency support. Each one is a place an unattended run stops, which is usually what sends someone looking in the first place.
What this category actually supports
Across the 11 products scored in Browser Automation, automate a browser is offered by 100%, capture a screenshot is offered by 27%, fill a web form is offered by 0%. Anything under half is a gap you should expect to fill yourself whichever one you pick.
An agent can get this list directly: resolve("alternative to Kernel") over the MCP server, or GET /v1/categories/browser-automation.