Claude Opus 4.8 vs Claude Sonnet 5 for emotional support

The verdict

Effectively a dead heat: 9896

Same 12 emotional support tasks, marked blind by three rival labs. Claude Sonnet 5 took 3 tasks, Claude Opus 4.8 took 0, 9 tied. Tested 16 Aug 2026.

Where they differed most

The task — Driving test at 9am

Your nephew texts at 10pm: 'Test tomorrow 9am. Third attempt. If I fail again I'm done, and everyone at work knows this time.' Write the reply: steady him tonight without hollow certainty — you do not know he will pass, so do not promise it — give him one practical thing for the morning, and take the weight out of the third-attempt story.

Here's a reply:

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Hey. Okay, big night. First thing: I'm not going to tell you you'll pass, because I don't know that and you'd smell the BS anyway. What I do know is you can walk in there and give it a real shot, and that's the only part that's actually in your hands tonight.

The "third attempt, everyone knows" stuff — that's a story your brain is running to make this feel bigger than it is. It's one test on one Tuesday. Whatever happens, you'll still have a Wednesday, and options, and people who don't rank you by a pass/fail. That part d…
Hey. That's a lot to be carrying at 10pm the night before.

I'm not going to tell you you've got this in the bag — I don't know that, and you'd see through it anyway. What I do know: third attempt doesn't mean anything about you except that you didn't quit. It's not a verdict, it's just a number. People pass on the fifth try and forget it ever mattered a year later. The story where everyone's watching and this is "the one that decides everything" — that's the part that'll actually hurt you tomorrow, not the material. Your brain is scared, so it…

Task by task

TaskClaude Opus 4.8Claude Sonnet 5
The dog died1010
Redundant at 551010
She said no advice1010
After the miscarriage1010
Driving test at 9am89
First Father's Day after910
The 3am calls910
Days without speaking1010
Stop apologising1010
Not a diagnosis99
Her promotion, your rejection1010
The 1am message1010

Full receipts: Claude Opus 4.8, Claude Sonnet 5 · judges gemini-3.1-pro-preview, gpt-5.6-terra, grok-4.5

Questions people ask

Which is better for emotional support: Claude Opus 4.8 or Claude Sonnet 5?

Effectively a dead heat: Claude Sonnet 5 edged it 98/100 to 96/100 on our emotional support 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 emotional support 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 emotional support head-to-heads: Claude Sonnet 5 vs GPT-5.5 · Claude Sonnet 5 vs DeepSeek V4 Pro · Claude Fable 5 vs Claude Sonnet 5 · Claude Sonnet 5 vs GPT-5.6 Sol · Claude Sonnet 5 vs GPT-5.6 Luna · Claude Sonnet 5 vs GPT-5.3-Codex

Full ranking: Best AI for emotional support · model pages: Claude Opus 4.8, Claude Sonnet 5