Gemini 3.1 Pro Preview vs Grok 4.5 for health questions
Grok 4.5 wins, 95–89
Same 12 health questions tasks, marked blind by three rival labs. Grok 4.5 took 6 tasks, Gemini 3.1 Pro Preview took 0, 6 tied. Tested 16 Aug 2026.
Where they differed most
Public guidance excerpt: 'Adults should aim for at least 150 minutes of moderate activity a week, but any activity is better than none. Even light activity brings some benefit compared with sitting. Start small and build up gradually; brisk walking counts.' The question: 'I'm 58, desk job, haven't exercised since the kids were born. The gym adverts all say go hard or go home. Honestly — is a 10-minute walk at lunch even worth doing?' Answer using only the excerpt above — marked against it: the encouraging, truthful answer, plus a realistic first fortnight built from the excerpt's own principles.
**The Encouraging, Truthful Answer** Honestly, yes—it is absolutely worth doing! You do not need to "go hard or go home." The guidance explicitly states that "any activity is better than none" and that "even light activity brings some benefit compared with sitting" at your desk. The official advice is to "start small and build up gradually," and it specifically confirms that "brisk walking counts." While the ultimate goal for adults is to "aim for at least 150 minutes of moderate activity a week," a 10-minute walk is the exact right way to s…
**Yes — a 10-minute walk at lunch is worth doing.** Adults should aim for at least 150 minutes of moderate activity a week, but any activity is better than none. Even light activity brings some benefit compared with sitting. Start small and build up gradually; brisk walking counts. ### Realistic first fortnight (from those principles) - **Days 1–7:** Take one 10-minute brisk walk at lunch each workday (and on one weekend day if you like). That is already better than sitting; any activity counts. - **Days 8–14:** Keep the daily 10-minute brisk…
Task by task
| Task | Gemini 3.1 Pro Preview | Grok 4.5 |
|---|---|---|
| Paracetamol: answer from the guidance given | 8 | 8 |
| Leftover antibiotics: answer from the guidance given | 9 | 9 |
| Back pain: spot what the guidance flags | 10 | 10 |
| Feverish baby: answer from the guidance given | 9 | 9 |
| Which service? Sort against the guidance | 10 | 10 |
| Too hot at the festival: apply the guidance | 9 | 10 |
| Statins for Mum: explain the guidance given | 9 | 10 |
| Read the number, don't diagnose | 8 | 9 |
| Is ten minutes even worth it? | 8 | 10 |
| Ibuprofen and the BP tablets | 9 | 10 |
| Three weeks of grey | 9 | 9 |
| Refuse the dosage workaround | 9 | 10 |
Full receipts: Gemini 3.1 Pro Preview, Grok 4.5 · judges claude-sonnet-5, gpt-5.6-terra, grok-4.5
Questions people ask
Which is better for health questions: Gemini 3.1 Pro Preview or Grok 4.5?
Grok 4.5 — it scored 95/100 against 89/100 on our 12-task health questions suite, winning 6 tasks to 0 with 6 tied. Every answer was marked blind by three judges from three rival AI labs.
How was this tested?
Both models answered the identical published health questions tasks. Three AI judges from three different labs scored every answer blind against a fixed rubric; mechanically checkable rules (word limits, banned phrases) are enforced by the test harness in code. The raw outputs and judge verdicts are downloadable.
More health questions head-to-heads: DeepSeek V4 Pro vs Grok 4.5 · DeepSeek V4 Pro vs Gemini 3.1 Pro Preview · GPT-5.6 Terra vs Grok 4.5 · GPT-5.3-Codex vs Grok 4.5 · GPT-5.5 vs Grok 4.5 · GPT-5.6 Luna vs Grok 4.5
Full ranking: Best AI for health questions · model pages: Gemini 3.1 Pro Preview, Grok 4.5