RefusalBench (Nous Research)
Models get requests in scenarios that closed and open models commonly refuse. The score is the percent of questions the model answers, averaged over 5 trials.
Nous introduced it with Hermes 4 and keeps a RefusalBench leaderboard that it cites for Hermes 4.3. Higher means fewer refusals, which Nous treats as better steerability.
- Made by
- Nous Research
- Released
- August 2025
- Kind
- Deception and alignment
- Level
- Everyday
- Scored
- Graded by a model
- Answers
- Open-ended
- Tasks
- Kept private
- Last in a launch post
- December 2025, dropped before it saturated
- Last model added
- December 2025
Hermes 4.3 36B leads with 74.6%
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.
- 1 Hermes 4.3 36B 74.6%
- 2 Hermes 4 405B 57.1%
Source: Labs’ model cards
| # | Model | Score | Setting | Date | Source |
|---|---|---|---|---|---|
| 1 | Hermes 4.3 36B | 74.6% | Dec 2025 | Lab model card | |
| 2 | Hermes 4 405B | 57.1% | Aug 2025 | Lab model card |
2 models have held number one in labs’ own numbers since its release in August 2025
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 headline it less often now, last in December 2025
Launch posts from every lab that has listed it, one tick per post. Tall colored ticks include it, and short gray ones leave it out.
| Date | Launch post | Score | As the post writes it |
|---|---|---|---|
| Dec 3, 2025 | Hermes 4.3 36B | 74.6 | RefusalBench, % of questions answered, non-reasoning (reasoning 72.29), average of 5 trials |
| Aug 26, 2025 | Hermes 4 405B | 57.1 | RefusalBench (reasoning) |
One system card reports it
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 |
|---|---|---|---|---|
| Aug 25, 2025 | Hermes 4 405B technical report | 57.1 | RefusalBench, average of 5 runs, higher means fewer refusals (also Figure 4), reasoning mode (Table 3). Non-reasoning 43.2 | 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%