Google Cloud Agent Evaluation vs Promptfoo

Google Cloud Agent Evaluation helps measure and improve agent performance, safety, and quality. Its workflow runs from defining evaluation cases through inference, behavior-trace capture, metric calculation, result analysis, and optimization. It can generate varied, multi-turn test scenarios from agent instructions and tool definitions, and intercept tool calls to supply custom behavior, mocked data, or simulated errors such as HTTP 503 responses and latency spikes. Prebuilt or custom raters score traces with reference-based Exact Match or reference-free Helpfulness metrics. Teams can also evaluate production-traffic traces or external logs without a managed test environment. Prompt optimization identifies failure points and proposes focused system-instruction changes. The service supports tool-call checks, safety evaluations, regression runs, trace ingestion, and custom models. Access is through API or web, with notebook launch options for Colab, Colab Enterprise, Agent Platform Workbench, and GitHub. Pricing is usage-based: $0.00003 per 1k input characters and $0.00009 per 1k output characters for computation-based metrics; model-based metrics also incur underlying autorater model costs. New Google Cloud customers get $300 in trial credits.

Promptfoo helps developers and enterprises evaluate prompts and test AI applications for security risks. It compares prompt outputs across multiple models in a web view. Red-team testing simulates users to look for prompt injections, jailbreaks, data leaks, business rule violations and insecure agent tool use. Its getting-started guide lists more than 60 providers, including OpenAI, Anthropic, Google and local models such as Ollama. Integrations include CI systems such as GitHub Actions, GitLab CI, Jenkins, Azure Pipelines, CircleCI and Bitbucket Pipelines, plus Splunk, Burp Suite, Google Sheets and MCP. Installation is available through npm, npx or Homebrew. Promptfoo requires Node.js 22.22.0 or newer and recommends Node.js 24 LTS. The free Community plan includes all LLM evaluation features and 10k red-team probes per month, and can run locally or be self-hosted. Enterprise includes managed cloud deployment; On-Premise runs on customer infrastructure. Promptfoo says it is based in San Francisco, is now part of OpenAI and remains open source.