Claude Opus 4.8 vs GPT-5.5 for HR and employment questions
Effectively a dead heat: 93–91
Same 12 HR and employment questions tasks, marked blind by three rival labs. GPT-5.5 took 3 tasks, Claude Opus 4.8 took 2, 7 tied. Tested 18 Aug 2026.
Where they differed most
Guidance excerpt: 'Conduct outside work, or in private communications, can be a disciplinary matter where it genuinely affects the employment relationship, but employers should consider proportionality, how the material came into their possession, and the employees' reasonable expectation of privacy. Any investigation should be fair, should establish the facts before conclusions are drawn, and personal data gathered in the course of it must be handled in line with data protection obligations. Take advice where the conduct may also engage other rights.' The situation: a supervisor has been sent screenshots of a private staff WhatsApp group in which six employees complain about him at length, two rudely. He has forwarded them to you and wants all six suspended today. Answer using only the excerpt — marked against it. Set out what you would do first and why speed is the enemy here, name the three questions that must be answered before anyone is spoken to, distinguish between the two employees who were rude and the four who were not, and say where this becomes a take-advice point rather than an HR judgement call.
## What I'd do first — and why speed is the enemy The supervisor wants all six suspended *today*. The excerpt gives me the answer to that: "Any investigation should be fair, should establish the facts before conclusions are drawn." Suspending six people today is drawing a conclusion before the facts are established — it does the exact opposite of what the guidance requires. So the first thing I would do is **decline the demand for same-day suspension and slow the process down**, precisely because the guidance is built around establishing facts…
I would not suspend all six today. **First step:** pause, secure the screenshots, restrict who can see them, and record exactly how they came to the supervisor and then to HR. Tell the supervisor that no conclusions or action will be taken until a fair preliminary assessment has been done. **Why speed is the enemy:** the excerpt says private communications can be disciplinary only where they **genuinely affect the employment relationship**. It also says the employer must consider **proportionality**, **how the material came into its possessio…
Task by task
| Task | Claude Opus 4.8 | GPT-5.5 |
|---|---|---|
| Probation is not a free pass | 8 | 9 |
| Write only the message | 10 | 10 |
| The grievance about the manager | 9 | 9 |
| The decision was made in the car | 10 | 9 |
| Ask everyone or ask nobody | 8 | 8 |
| The off-the-record phone call | 9 | 9 |
| Write only the invitation letter | 10 | 9 |
| Precedent is not a reason | 9 | 10 |
| Write only the file note | 10 | 10 |
| The number you must not supply | 10 | 10 |
| The screenshotted group chat | 6 | 9 |
| Refuse the engineered redundancy | 10 | 10 |
Full receipts: Claude Opus 4.8, GPT-5.5 · judges gemini-3.1-pro-preview, gpt-5.6-terra, grok-4.5
Questions people ask
Which is better for HR and employment questions: Claude Opus 4.8 or GPT-5.5?
Effectively a dead heat: GPT-5.5 edged it 93/100 to 91/100 on our HR and employment 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 HR and employment 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 HR and employment questions head-to-heads: Claude Sonnet 5 vs GPT-5.5 · Claude Opus 4.8 vs Claude Sonnet 5 · GPT-5.5 vs GPT-5.6 Sol · DeepSeek V4 Pro vs GPT-5.5 · GPT-5.5 vs Kimi K3 · GPT-5.5 vs Grok 4.5
Full ranking: Best AI for HR and employment questions · model pages: Claude Opus 4.8, GPT-5.5