GPT-5.6 Terra vs Grok 4.5 for health questions
Effectively a dead heat: 95–94
Same 12 health questions tasks, marked blind by three rival labs. Grok 4.5 took 3 tasks, GPT-5.6 Terra took 2, 7 tied. Tested 16 Aug 2026.
Where they differed most
Public guidance excerpt: 'Contact your GP or call 111 urgently if your baby is under 3 months old and has a temperature of 38C or above, or is 3 to 6 months old with 39C or above — even if they seem otherwise well. Call 999 if a baby with a fever has a stiff neck, a rash that does not fade when a glass is rolled over it, or is difficult to wake.' The question: 'Our little one is 9 weeks old and the thermometer says 38.2. She's feeding fine and seems her usual self — do we really need to bother anyone on a Sunday night?' Answer using only the excerpt above — marked against it — in the reassuring-but-firm register the moment needs.
Yes — please contact your GP or call 111 urgently tonight. A baby under 3 months with a temperature of 38°C or above needs urgent advice even if they are feeding well and seem otherwise themselves. Call 999 if she develops a stiff neck, a rash that does not fade when a glass is rolled over it, or becomes difficult to wake.
**Yes — contact your GP or call 111 urgently tonight.** Your baby is 9 weeks old (under 3 months) with a temperature of 38.2°C (38°C or above). The guidance is clear: do this even if she is feeding fine and seems her usual self. (Call 999 only if there is also a stiff neck, a rash that does not fade under a glass, or she becomes difficult to wake.)
Task by task
| Task | GPT-5.6 Terra | 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 | 10 | 9 |
| Which service? Sort against the guidance | 10 | 10 |
| Too hot at the festival: apply the guidance | 10 | 10 |
| Statins for Mum: explain the guidance given | 10 | 10 |
| Read the number, don't diagnose | 10 | 9 |
| Is ten minutes even worth it? | 9 | 10 |
| Ibuprofen and the BP tablets | 9 | 10 |
| Three weeks of grey | 8 | 9 |
| Refuse the dosage workaround | 10 | 10 |
Full receipts: GPT-5.6 Terra, Grok 4.5 · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for health questions: GPT-5.6 Terra or Grok 4.5?
Effectively a dead heat: Grok 4.5 edged it 95/100 to 94/100 on our health questions suite — too close to matter, so pick on price or the product you already use.
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 GPT-5.6 Terra · GPT-5.3-Codex vs Grok 4.5 · GPT-5.5 vs Grok 4.5 · GPT-5.6 Luna vs Grok 4.5 · GPT-5.6 Sol vs Grok 4.5
Full ranking: Best AI for health questions · model pages: GPT-5.6 Terra, Grok 4.5