Comparison

AI chatbot testing tools for customer-facing agents

Compare 9 chatbot testing tools, from Promptfoo, DeepEval and Garak to Botium, Cekura, Hamming and Coval, by pricing model, licence, free tier and channels.

Last updated . For the testing standard behind these comparisons, read the methodology.

9 chatbot testing tools: which workflow fits?

Published by Agent Torture Lab, one of the products compared. Pricing and licences checked on 30 September 2026 against each vendor's own site; check current terms before buying. This is a scope comparison of documented capabilities, not a hands-on benchmark or a ranking of test accuracy. Where a vendor does not publish a fact, the table says so instead of guessing.

Compare best fit, pricing model, licence, free tier, channels, evidence, and limits
Tool / official siteBest fit and setupPricing modelLicenceFree tierChannelsEvidence and limitsLast verified
Agent Torture LabA one-time launch decision for a customer-facing text agent

Public API endpoint; website checks are compatibility-gated; transcript fallback

Free preview, then a one-time full report at $29 (launch price); agencies buy prepaid creditsProprietaryYes: free report previewText agents onlyReport preview, transcript evidence with deterministic scoring, severity, fix list, and retest plan

Does not monitor production traffic: it is not a monitoring service, a voice test suite, or a complete security assessment.

Source

PromptfooDeveloper-owned evaluations and adversarial testing

Configure providers, test cases, and assertions; HTTP endpoints supported

Open-source Community plan; Enterprise and On-Premise plans are custom-pricedOpen source: MIT (its README says Promptfoo is now part of OpenAI and remains MIT)Yes: Community plan, free forever; red teaming capped at 10k probes a monthText LLM apps and models; voice not statedEvaluation results and red-team findings in a developer workflow

Your team configures the target and defines the relevant test expectations.

Source · Licence

DeepEval (Confident AI)Code-owned LLM and chatbot evals in a Pytest-style workflow

Python package; write test cases and choose metrics and thresholds

Open-source framework; Confident AI cloud has Free, $200/month Starter, $2,000/month Team, and custom Enterprise plansOpen source: Apache-2.0 (DeepEval); Confident AI cloud licence not publishedYes: DeepEval is free; the Confident AI Free plan has 2 seats, 1 project, and 5 test runs a weekText LLM apps, including multi-turn chatbots; some image metricsPer-test-case metric scores, including multi-turn conversational metrics

Your team writes the test cases and decides which metrics and thresholds matter.

Source · Licence

Garak (NVIDIA)LLM vulnerability scanning: prompt injection, jailbreak, and data leakage probes

Python CLI; point a generator at a model or any REST endpoint

Free open-source toolOpen source: Apache-2.0Yes: the README describes garak as a free toolText: LLMs and dialog systems, including REST endpointsA JSONL report of every probe attempt and its evaluation, plus a run log

Probes the model or endpoint for weaknesses; business-policy and customer-journey coverage is up to your team.

Source

GiskardAI security testing and red teaming

Connect the AI application and select the security assessment scope

Free open-source library; Enterprise price not published (contact sales)Open source: Apache-2.0 (giskard-oss library); Enterprise Hub licence not publishedYes: open-source library at $0 for solo LLM experimentsText LLM apps and agentsSecurity findings and assessment reports

Validate business-policy and customer-handoff coverage separately from security coverage.

Source · Licence

Cyara BotiumConversational QA across channels and customer journeys

Configure connectors; Cyara lists 55+ conversational AI platforms

Not published (demo request)Botium Core: open source (MIT); Cyara Botium platform licence not publishedBotium Core is free; no platform free tier publishedChat and voiceFunctional, regression, performance, and security test results, plus monitoring

Check connector compatibility and implementation effort for your actual bot.

Source · Licence

CekuraVoice and chat agent testing with production monitoring

Integrate the agent and configure scenarios and evaluation criteria

Pay as you go ($0.25 per voice-testing minute), $500/month Startup, or custom EnterpriseProprietary (no open-source licence published)Yes: first user free on pay as you go, plus 300 free credits (about 60 minutes)Voice and chatSimulation results and monitoring insights

Check supported integrations, usage pricing, and channel-specific coverage.

Source

HammingVoice and chat agent testing, red teaming, and production call monitoring

Scenarios auto-generated from your agent's prompt

Contact sales (Agency, Startup, and Enterprise plans)Proprietary (no open-source licence published)Homepage offers "Start testing free"; limits not publishedVoice and chatTest reports and monitoring of production calls

No public prices; confirm plan terms and channel coverage with the vendor.

Source

CovalVoice agent simulation, evals, and production monitoring

Simulation minutes and monitored calls; access via API, CLI, and MCP

$100/month Starter, $500/month Growth, Enterprise from $4,500/monthProprietary (no open-source licence published)7-day free trial on Starter and Growth (credit card required); no free plan publishedVoice and chatSimulation results and production evals on live conversations

Voice-first; confirm chat depth for your use case.

Source

For a fair trial, run the same chatbot test-case pack against the same version of your agent. Compare failed conversations, evidence quality, and time to an actionable fix. Start with the QA checklist if you have not defined coverage yet.

Need a one-time report? Inspect the sample API report and current launch pricing. Confirm recurring vendor prices directly before buying.

Best fit

Use Agent Torture Lab when...

  1. Teams evaluating tools before launching an AI chatbot.
  2. Customer-support and sales operators who care about real conversation outcomes.
  3. Agencies comparing ways to prove client bots were tested.
Limits

When another tool is the better choice

  1. Choose a voice-focused tool such as Cekura or Hamming if you are testing voice or phone agents.
  2. Choose Promptfoo or DeepEval if you want code-owned eval suites that run in CI.
  3. Choose a monitoring or observability tool if you need continuous production monitoring. Agent Torture Lab does not monitor live traffic.
Decision matrix

What changes when the goal is a launch report?

Criterion

Scenario coverage

Agent Torture Lab: Prebuilt risk families for customer pressure and launch blockers.

Alternative approach: Some tools require teams to author every test from scratch.

Criterion

Report quality

Agent Torture Lab: Built around stakeholder-readable findings and fixes.

Alternative approach: May stop at logs, screenshots, or pass/fail rows.

Criterion

Retesting

Agent Torture Lab: Findings include what to rerun after the fix.

Alternative approach: Reruns can require manual reconstruction of the original failure.

Criterion

Business fit

Agent Torture Lab: Support, ecommerce, sales, services, and client handoff.

Alternative approach: May focus on technical evals, monitoring, or chatbot building instead.

Red-team tools

Red-team and security testing tools

Red-team tools uncover adversarial failures such as prompt injection, policy bypass, unsafe advice, and data leakage. Of the tools in the table above, Promptfoo supports adversarial testing in a developer workflow, Garak is NVIDIA's open-source scanner that probes LLMs and REST endpoints for prompt injection, jailbreaks, and data leakage, and Giskard focuses on AI security testing and red teaming.

Use a specialist tool or security team when the scope includes infrastructure, broader model-safety programs, regulated high-risk systems, or deep exploit research. Agent Torture Lab treats prompt-injection pressure as one part of a customer-facing launch test and reports it without publishing bypass recipes.

Manual QA

Manual chatbot QA

Manual QA is better for taste, brand nuance, unusual product context, and exploratory review that does not need repeatable scoring. It is hard to repeat consistently across launches, and findings often end up as notes or screenshots instead of transcript evidence.

The strongest process combines both: repeatable pressure tests first, then human review of the transcript-backed findings for brand judgment and the final launch call.

Takeaways

The practical call.

  1. Pick a tool based on the decision you need to make after the test.
  2. For customer-facing bots, transcript evidence matters more than abstract scores.
  3. A strong testing workflow should make the fix and retest obvious.
  4. Check integration effort and data handling against your actual deployment before adopting any tool.
  5. Compare cost shape, not only features. A one-time guest launch report is $29 at current launch pricing; check each vendor’s current pricing for recurring platforms and usage charges.
  6. If you already run DeepEval, Giskard, Botium, Cekura, or Promptfoo, use a launch report as the fast pre-launch and client-handoff layer on top.
Decision filters
01

Which high-risk customer journeys does the tool cover out of the box?

02

Does the tool produce a report, a dashboard, raw logs, or only pass/fail checks?

03

Can the team rerun the same failing scenario after a fix?

04

Does it test support, sales, ecommerce, and service behavior in the language customers actually use?

Buyer questions

Ask these before choosing a testing approach.

  1. Which high-risk customer journeys does the tool cover out of the box?
  2. Does the tool produce a report, a dashboard, raw logs, or only pass/fail checks?
  3. Can the team rerun the same failing scenario after a fix?
  4. Does it test support, sales, ecommerce, and service behavior in the language customers actually use?
FAQ

Short answers for buyers and builders.

What should an AI chatbot testing tool check?

It should check policy adherence, unsafe claims, privacy handling, prompt-injection resistance, escalation, conversion blockers, tone under pressure, and retestability.

Is a chatbot testing tool the same as a chatbot builder?

No. A builder creates the bot. A testing tool checks whether the bot behaves safely and usefully before customers rely on it.

How do I choose between AI chatbot testing tools?

Choose based on the decision you need after testing. For launch readiness, prioritize scenario coverage, transcript evidence, severity, fix guidance, and retesting.

Do chatbot testing tools need prompt-injection tests?

Yes, but prompt injection should be one part of a broader customer-facing test set that also covers policy, privacy, escalation, and conversion behavior.

What are the main AI chatbot testing tools?

Examples include Promptfoo and DeepEval for developer evaluations, Garak and Giskard for LLM security and red teaming, Cyara Botium for conversational testing, Cekura, Hamming, and Coval for voice and chat agent testing and monitoring, and Agent Torture Lab for a one-time text-agent launch report. Choose by the workflow and evidence you need.

Which chatbot testing tools are free or open source?

Checked on 30 September 2026 against each project's official repository: Promptfoo (MIT), DeepEval (Apache-2.0), Garak (Apache-2.0), Giskard's open-source library (Apache-2.0), and Botium Core (MIT) are open source. Cekura offers a pay-as-you-go plan with the first user free, Confident AI (the company behind DeepEval) has a free cloud plan, and Coval offers a 7-day free trial. Agent Torture Lab has a free report preview; the full report is a one-time purchase. Check current terms before relying on a free tier.

Related comparisons

Nearby questions worth checking.