GPT-5.5 vs GPT-5.6 Luna for CV writing

The verdict

GPT-5.5 wins, 95–88

Same 12 CV writing tasks, marked blind by three rival labs. GPT-5.5 took 6 tasks, GPT-5.6 Luna took 2, 4 tied. Tested 16 Aug 2026.

Where they differed most

The task — Back after eight years

A bookkeeper is returning to work after 8 years raising children. Recommend chronological or skills-led for her CV and say why in two sentences. Then write the single matter-of-fact line that goes where the gap sits — no apology — and say which two of these earn a place as evidence the skills stayed alive: treasurer of the PTA (£12k annual budget), ran the Race for Life 10k, completed a Xero online course in 2025, school reading volunteer.

GPT-5.59/10

Use a skills-led CV, with a brief reverse-chronological work history underneath. It puts her bookkeeping ability, recent training and relevant unpaid finance experience up front, rather than making the eight-year career break the headline.

**Gap line:**  
**2017–2025 | Career break: raising children**

**Evidence the skills stayed alive:**  
- **Treasurer of the PTA — managed a £12k annual budget**  
- **Completed a Xero online course in 2025**

GPT-5.6 Luna5/10

**Recommendation: chronological CV.** It shows her previous bookkeeping experience clearly while allowing recent, relevant evidence to sit alongside it; a skills-led CV may look as though it is hiding the eight-year gap.

**Gap line:**  
**2017–2025 | Full-time childcare and family responsibilities**

**Evidence to include:**
- Treasurer of the PTA, managing a **£12,000 annual budget**
- **Xero online course completed in 2025**

Task by task

Task	GPT-5.5	GPT-5.6 Luna
Profile that mirrors the ad	10	9
Untangle the dates	9	8
Duties into achievements	9	10
Thirty years onto two pages	10	8
Profile without the wallpaper	10	9
First CV, empty history	9	10
Back after eight years	9	5
Do the hobbies earn their line?	10	9
Fix the format	10	10
The Excel question	9	9
Strip the header	9	9
Refuse the invented job	10	10

Full receipts: GPT-5.5, GPT-5.6 Luna · judges claude-sonnet-5, gemini-3.1-pro-preview, grok-4.5

Questions people ask

Which is better for CV writing: GPT-5.5 or GPT-5.6 Luna?

GPT-5.5 — it scored 95/100 against 88/100 on our 12-task CV writing suite, winning 6 tasks to 2 with 4 tied. Every answer was marked blind by three judges from three rival AI labs.

How was this tested?

Both models answered the identical published CV writing 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 CV writing head-to-heads: GPT-5.3-Codex vs GPT-5.5 · Claude Opus 4.8 vs GPT-5.5 · GPT-5.5 vs GPT-5.6 Sol · Claude Fable 5 vs GPT-5.5 · GPT-5.5 vs GPT-5.6 Terra · Claude Opus 4.6 vs GPT-5.5

Full ranking: Best AI for CV writing · model pages: GPT-5.5, GPT-5.6 Luna