XSTest
Models answer 250 safe prompts that resemble unsafe ones and 200 unsafe contrast prompts. Labs usually report the incorrect refusal rate on safe prompts.
Anthropic model cards report the incorrect refusal rate on the non-malicious prompts, where lower is better.
- Released
- August 2023
- Kind
- Refusing harmful requests
- Level
- Everyday
- Scored
- Graded by a model
- Answers
- Open-ended
- Tasks
- All public
- Strongest model tested
- o1 #117 on the capability index
- Last in a system card
- March 2026
- Last model added
- March 2026
In the authors’ words
Without proper safeguards, large language models will readily follow malicious instructions and generate toxic content. This risk motivates safety efforts such as red-teaming and large-scale feedback learning, which aim to make models both helpful and harmless. However, there is a tension between these two objectives, since harmlessness requires models to refuse to comply with unsafe prompts, and thus not be helpful. Recent anecdotal evidence suggests that some models may have struck a poor balance, so that even clearly safe prompts are refused if they use similar language to unsafe prompts or mention sensitive topics. In this paper, we introduce a new test suite called XSTest to identify such eXaggerated Safety behaviours in a systematic way. XSTest comprises 250 safe prompts across ten prompt types that well-calibrated models should not refuse to comply with, and 200 unsafe prompts as contrasts that models, for most applications, should refuse. We describe XSTest's creation and composition, and then use the test suite to highlight systematic failure modes in state-of-the-art language models as well as more general challenges in building safer language models.
Cohere Command A leads with 1.10% among models released by January 2026
Best score per model as labs report them in their own cards. Labs pick their own settings, so these compare less cleanly than independent runs.
The newest model with a score here came out in January 2026, and nobody has reported a newer one. Among the 20 highest-ranked models on the capability index, these have no score yet:
- Claude Fable 5.2
-
Gemini 4 Carbon
- GPT-6 Astra
- Claude Opus 5.5
- and 16 more
- 1
Cohere Command A 1.10%
- 2 Claude 3.5 Sonnet 1.70%
- 3 Claude 3.5 Haiku 2.00%
- 4 Claude 3.5 Sonnet (October 2024) 4.30%
- 5 Claude 3 Opus 9.00%
- 6
Phi-4 Mini 20.8%
- 7
Phi-4-multimodal 26.4%
- 8 GPT-4.5 85%
- 9 o3-mini 88%
- 10
Olmo 3.1 32B Think 91.8%
- 11 o1 93.6%
- 12
Olmo 3 32B Think 93.9%
- 13 o1-mini 94.8%
- 14
DeepSeek-R1 95.3%
- 15
Falcon H1R 7B 96.4%
- 16 o1-preview 97.6%
Source: Labs’ model cards
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | | 1.10% | Apr 2025 | Lab model card | |
| 2 | Claude 3.5 Sonnet | 1.70% | Jun 2024 | Lab model card | |
| 3 | Claude 3.5 Haiku | 2.00% | Oct 2024 | Lab model card | |
| 4 | Claude 3.5 Sonnet (October 2024) | 4.30% | Oct 2024 | Lab model card | |
| 5 | Claude 3 Opus | 9.00% | Mar 2024 | Lab model card | |
| 6 | | 20.8% | Mar 2025 | Lab model card | |
| 7 | | 26.4% | Mar 2025 | Lab model card | |
| 8 | GPT-4.5 | 85% | Feb 2025 | Lab model card | |
| 9 | o3-mini | 88% | Jan 2025 | Lab model card | |
| 10 | | 91.8% | Dec 2025 | Lab model card | |
| 11 | o1 | 93.6% | Dec 2024 | Lab model card | |
| 12 | | 93.9% | Dec 2025 | Lab model card | |
| 13 | o1-mini | 94.8% | Sep 2024 | Lab model card | |
| 14 | | 95.3% | Jan 2025 | Lab model card | |
| 15 | | 96.4% | Jan 2026 | Lab model card | |
| 16 | o1-preview | 97.6% | Sep 2024 | Lab model card |
3 models have held number one in labs’ own numbers since its release in August 2023
Lab claims count from the day the card came out, independent runs from the model’s release.
Source: Labs’ model cards
Scores over time
All the scores we have, one dot each, so a model tested at several settings appears more than once.
Source: Labs’ model cards
Labs report it only in system cards
We read the headline results of 522 launch posts from 52 labs, and none of them list this benchmark. Some system cards do, below.
19 system cards report it, from 8 labs
Besides launch posts, we read the system cards, model cards and technical reports labs publish with a release. They report far more, including safety and frontier-risk tests.
| Date | Document | Score | As the document writes it | Section |
|---|---|---|---|---|
| Mar 21, 2026 | | XSTest, bar chart with no printed number (Figure 10) | Safety | |
| Jan 5, 2026 | | 96.4 | XSTest safe rate by Llama-Guard-3-8B, CoT+Answer, 98.0 Answer Only, 87.07 CoT Only (Table 10) | Safety |
| Dec 15, 2025 | | 93.9 | XSTest, refusal accuracy, Final Think 3.0 column (Table 54) | Safety |
| Dec 15, 2025 | | 91.8 | XSTest, refusal accuracy, Final Think 3.1 column (Table 54) | Safety |
| Apr 1, 2025 | | 1.1 | XSTest over-refusal, full 1.1 plus partial 0.0, lower is better (Table 17). Internal over-refusal set 7.1 | Safety |
| Mar 3, 2025 | | 26.4 | XSTest VPRR, refusal rate on valid prompts, lower is better. IPRR on inappropriate prompts 92% (Table 12) | Safety |
| Mar 3, 2025 | | 20.8 | XSTest VPRR, refusal rate on valid prompts, lower is better. IPRR on inappropriate prompts 93.5% (Table 12) | Safety |
| Feb 27, 2025 | GPT-4.5 system card | 85 | XSTest, not_overrefuse (Table 1) | Safety |
| Jan 31, 2025 | o3-mini system card | 88 | XSTest, not_overrefuse (Table 1) | Safety |
| Jan 20, 2025 | | 95.3 | XSTest safety score, from HELM (Table 9) | Safety |
| Dec 5, 2024 | o1 system card | 93.6 | XSTest, not_overrefuse, overall (Table 20, 0.94 in Table 1) | Safety |
| Oct 22, 2024 | Claude 3.5 Sonnet (October 2024) model card | 4.3 | XSTest, incorrect refusals, lower is better (Table 6) | Safety |
| Oct 22, 2024 | Claude 3.5 Haiku model card | 2 | XSTest, incorrect refusals, lower is better (Table 6) | Safety |
| Sep 12, 2024 | o1-preview system card | 97.6 | XSTest, not_overrefuse, overall (Table 1, Table 15) | Safety |
| Sep 12, 2024 | o1-mini system card | 94.8 | XSTest, not_overrefuse, overall (Table 1, Table 15) | Safety |
| Jun 20, 2024 | Claude 3.5 Sonnet model card | 1.7 | XSTest, incorrect refusals, lower is better (Table 4) | Safety |
| Mar 4, 2024 | Claude 3 Sonnet model card | XSTest, incorrect refusal rate, lower is better, log-scale chart without printed values (Figure 3) | Safety | |
| Mar 4, 2024 | Claude 3 Opus model card | 9 | XSTest, incorrect refusal rate, lower is better, 9% stated in text (5.4.1, Figure 3) | Safety |
| Mar 4, 2024 | Claude 3 Haiku model card | XSTest, incorrect refusal rate, lower is better, log-scale chart without printed values (Figure 3) | Safety |
More in Safety and alignment
- FORTRESS In use Paired adversarial and benign national-security misuse prompts. Rubric-graded risk score on adversarial and over-refusal score on benign prompts. Claude Opus 5.5 5.78%
- StrongREJECT In use Forbidden-prompt jailbreak benchmark with a rubric grader that scores how useful a non-refusal actually is.
Inkling 98.6%
- Gray Swan IPI Arena benchmark In use Indirect prompt-injection attacks from public red-teaming competitions replayed on tool, coding and browser agents. Attack success rate at k attempts.
Gemini 4 Carbon 0%
- DistressBench In use Models reply as a chatbot to 718 simulated users in psychological crisis, in single-turn and multi-turn chats. Three judge models score replies against clinician-written rubrics.
Muse Spark 1.2 88.4%
- Lakera B3 (Backbone Breaker Benchmark) In use Crowdsourced prompt-injection attacks hit backbone LLMs inside agent threat snapshots at three defense levels. The score is attack resistance, 100 minus the board's vulnerability percentage. Claude Opus 4.5 89%
- IHEval In use Models face conflicts between system, user and tool instructions. Reports a composite score for following the higher-priority instruction. GPT-4o 70%