Claude Sonnet 5 vs GPT-5.6 Sol for humanising AI text
Effectively a dead heat: 96–94
Same 12 humanising AI text tasks, marked blind by three rival labs. Claude Sonnet 5 took 1 task, GPT-5.6 Sol took 1, 10 tied. Tested 16 Aug 2026.
Where they differed most
Rewrite this product description naturally, keeping every spec — 750ml, stainless steel, cold 24 hours, hot 12, £24, free engraving: 'Introducing the ultimate hydration solution for the modern lifestyle. This premium 750ml vessel is expertly crafted from high-grade stainless steel, delivering unparalleled temperature retention — beverages remain refreshingly cold for an impressive 24 hours or delightfully hot for 12. Elevate your everyday experience for just £24, with complimentary personalised engraving included.' Sound like a good market stall, not a press release.
Here's your 750ml stainless steel bottle – proper quality kit, this. Keeps drinks cold for a full 24 hours, or if you fancy something hot, that'll stay warm for 12. Yours for just £24, and we'll even engrave it for you free of charge. Great stuff!
Stay refreshed all day with this 750ml stainless steel bottle. It keeps drinks cold for up to 24 hours or hot for up to 12 hours. Just £24, including free personalised engraving.
Task by task
| Task | Claude Sonnet 5 | GPT-5.6 Sol |
|---|---|---|
| The touching-base email | 10 | 10 |
| De-guru the bio | 10 | 10 |
| Product page, human voice | 10 | 7 |
| Strip the tics | 9 | 9 |
| The head's newsletter | 9 | 10 |
| The condolence card | 10 | 10 |
| Reply to the review, humanly | 10 | 10 |
| About us, actually about us | 10 | 10 |
| Best man, not best template | 9 | 9 |
| Human but still formal | 9 | 9 |
| Change log required | 9 | 9 |
| Refuse the disguise job | 10 | 10 |
Full receipts: Claude Sonnet 5, GPT-5.6 Sol · judges gemini-3.1-pro-preview, gpt-5.6-terra, grok-4.5
Questions people ask
Which is better for humanising AI text: Claude Sonnet 5 or GPT-5.6 Sol?
Effectively a dead heat: Claude Sonnet 5 edged it 96/100 to 94/100 on our humanising AI text 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 humanising AI text 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 humanising AI text head-to-heads: Claude Sonnet 5 vs GPT-5.3-Codex · GPT-5.3-Codex vs GPT-5.6 Sol · Claude Fable 5 vs Claude Sonnet 5 · Claude Sonnet 5 vs GPT-5.5 · Claude Sonnet 5 vs GLM 5.2 · Claude Sonnet 5 vs GPT-5.6 Terra
Full ranking: Best AI for humanising AI text · model pages: Claude Sonnet 5, GPT-5.6 Sol