GPT-5.6 Luna vs GPT-5.6 Sol for social media posts
Effectively a dead heat: 100–98
Same 12 social media posts tasks, marked blind by three rival labs. GPT-5.6 Sol took 2 tasks, GPT-5.6 Luna took 0, 10 tied. Tested 16 Aug 2026.
Where they differed most
A customer review reads: 'Van broke down at 7am, they got me a courtesy car by 9 and my van back same day. Blown away.' Write a LinkedIn post (max 90 words) for the garage sharing this: quote a short phrase from the review verbatim in quote marks, credit 'a customer' not a made-up name, no self-congratulation words ('proud', 'humbled').
A van breakdown at 7am can derail the whole day. We were pleased to help get a courtesy car arranged by 9am and the van returned the same day. “Blown away.” Thanks to a customer for sharing this feedback. We’re here to keep you moving when the unexpected happens. #CustomerService #VehicleRepair #GarageSupport
“Blown away.” That’s how a customer described their experience after their van broke down at 7am. We arranged a courtesy car by 9am and had their van back on the road the same day. When your vehicle keeps your business moving, every hour matters. Our team will always do everything possible to minimise downtime and get you moving again. #CustomerService #GarageServices #VehicleRepair
Task by task
| Task | GPT-5.6 Luna | GPT-5.6 Sol |
|---|---|---|
| LinkedIn without the cringe | 10 | 10 |
| X thread that earns its length | 10 | 10 |
| Announce without announcing | 10 | 10 |
| Turn a review into a post | 9 | 10 |
| Disagree agreeably | 10 | 10 |
| The unsexy business | 10 | 10 |
| Say less | 10 | 10 |
| Hook without bait | 10 | 10 |
| Post about a mistake | 10 | 10 |
| Event post with the facts | 9 | 10 |
| Know when not to post | 10 | 10 |
| Refuse the astroturf | 10 | 10 |
Full receipts: GPT-5.6 Luna, GPT-5.6 Sol · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5
Questions people ask
Which is better for social media posts: GPT-5.6 Luna or GPT-5.6 Sol?
Effectively a dead heat: GPT-5.6 Sol edged it 100/100 to 98/100 on our social media posts 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 social media posts 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 social media posts head-to-heads: GPT-5.6 Sol vs GPT-5.6 Terra · GPT-5.3-Codex vs GPT-5.6 Sol · Claude Opus 4.8 vs GPT-5.6 Sol · GPT-5.5 vs GPT-5.6 Sol · DeepSeek V4 Pro vs GPT-5.6 Sol · GPT-5.6 Sol vs Grok 4.5
Full ranking: Best AI for social media posts · model pages: GPT-5.6 Luna, GPT-5.6 Sol