Knowledge Base

Guides and in-depth comparisons covering the questions we get most — on LLM evaluation, observability, and choosing the best AI testing tools and platforms. Updated continuously.

Playbooks

Step-by-step guides to set up and run LLM evaluation workflows.

Playbook Overview

What this handbook is for, who should read it, and what you will walk away with.

What Makes a Good Eval

Good evaluation is automated metrics locked to human judgment — neither side alone is enough.

What Should I Measure?

Before you pick a metric, figure out which business outcome it needs to predict — everything else follows from that.

When Should I Start Tracing?

Set up tracing before you need it — everything else (datasets, annotations, evals) depends on having the data flowing first.

User-Facing vs. Non-User-Facing Apps

The same LLM stack does not imply the same definition of quality — user-facing and internal apps optimize different dimensions.

Single-Turn vs. Multi-Turn Use Cases

Multi-turn failures show up across turns — not in any single response — which is why a separate evaluation strategy matters.

Dev, Staging, and Production

Evaluation is different work in each environment — dev is for iteration, staging is for regression, production is for monitoring.

Setting Up Trigger Moments (Online Evals)

How to choose where to run online evaluations in your LLM app, and in what order.

Setting Up AI Agent Observability

What agent observability actually captures, why traditional application monitoring and generic LLM observability miss agent failures, and how to turn traces into a quality loop instead of a log dump.

Evaluating AI Agents

What to measure at each layer of an agent, how to build a test harness that survives contact with production, and how to gate releases on agent quality without slowing the team down.

Setting Up Multi-Turn Agent Observability

The unit of quality for a multi-turn agent is not the request — it is the thread. How to instrument production agents and chatbots so the conversation is a first-class object in the trace store, not something you reconstruct from a session ID after a complaint comes in.

Evaluating Multi-Turn Chatbots

A chatbot can score green on every individual reply and still fail the user's actual request twelve turns later. How to evaluate both trace-level turns and conversation-level outcomes with scenario-based simulation and CI gates.

Compare

In-depth comparisons and rankings of the best LLM evaluation, observability, and AI testing tools and platforms.

7 Best Web Search APIs for Grounding LLMs in 2026

Compare the seven best web search APIs for grounding LLMs in 2026, including Firecrawl, Brave Search, Exa, Tavily, Parallel, Google Search grounding, and SerpApi.

7 Best AI Evaluation Tools for Enterprises in 2026

Compare the 7 best AI evaluation tools for enterprises in 2026. We rank platforms by their ability to standardize evals and observability across the org.

Top 9 Platforms for Pre-Deployment AI Testing in 2026

Compare the top 9 platforms for pre-deployment AI testing in 2026. We rank tools by evaluation depth, testing the app as deployed, and security testing.

9 Best LLM Evaluation Tools for Product Managers in 2026

Compare the 9 best LLM evaluation tools for product managers in 2026. We rank platforms by no-code accessibility, custom metrics and alignment, and monitoring with dashboards.

6 Best LLM Evaluation Tools for Startups in 2026

Compare the 6 best LLM evaluation tools for startups in 2026. We rank platforms by automation and setup speed, production-trace workflows, and startup-friendly pricing.

Top 6 Human-in-the-Loop Tools for AI Agent Evaluation (2026, Tested and Reviewed)

AI agents fail across tool calls, retrieval, and handoffs. We reviewed the six human-in-the-loop tools that get SMEs and QA into AI agent evaluation.

Top 8 CI/CD Tools for AI Applications in 2026

The eight best CI/CD tools for AI applications in 2026, ranked for LLM regression testing and release gates.

Best 7 Tools for Testing LLM Apps Before Production in 2026

The best tools for pre-production LLM app testing, ranked by how well they test whole-app behavior and catch regressions.

Top 7 AI Agent Observability Platforms for 2026

The seven AI agent observability platforms that matter in 2026 are the ones that score what they capture, surface failing runs, and turn production traces into the next test cycle.