// head_to_head
Claude Opus 4.8 vs GPT-5.6 Luna
Published LiveBench scores across all seven categories, live list pricing, context windows, and the measured cost of a point of capability — for both models, side by side.
Claude Opus 4.8 scores higher, GPT-5.6 Luna costs less — it depends on your workload.
Claude Opus 4.8 is ahead by 2.7 points overall, and GPT-5.6 Luna lists 22× cheaper per blended million tokens. Whether 2.7 points is worth that depends on how much a wrong answer costs you. GPT-5.6 Luna also leads on measured cost per point of capability, at $0.0911 per point.
anthropic
Claude Opus 4.8
- Blended / 1M
- $10.00
- Context
- 1M
- Released
- May 27, 2026
- Overall score
- 76.2
openai
GPT-5.6 Luna
- Blended / 1M
- $0.450
- Context
- 1.1M
- Released
- Jul 9, 2026
- Overall score
- 73.6
Specs and pricing
| Metric | Claude Opus 4.8 | GPT-5.6 Luna |
|---|---|---|
| LiveBench overall Mean of the seven LiveBench category scores, 0–100. Higher is better. | 76.2win | 73.6 |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | $0.5347 | $0.0911win |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $10.00 | $0.450win |
| Input price / 1M | $5.00 | $0.200win |
| Output price / 1M | $25.00 | $1.20win |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.500 | $0.020win |
| Context window | 1M | 1.1M |
| Max output tokens | 128K | 128K |
Benchmarks by category
An overall score averages away the thing you probably care about. These are the seven LiveBench categories scored separately — Claude Opus 4.8 on top, GPT-5.6 Luna below, both out of 100.
What each one costs to run
Per-token prices are hard to feel. These are monthly list costs for both models across five workload shapes, using each provider's published cached-input rate where there is one.
| Workload | Claude Opus 4.8 | GPT-5.6 Luna |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $2876.00/mo | $131.04/mo |
| RAG assistant 8K in / 600 out × 100K requests | $3700.00/mo | $160.00/mo |
| Coding agent 40K in / 4K out × 20K requests | $3480.00/mo | $155.20/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $6650.00/mo | $281.00/mo |
| Bulk classification 500 in / 20 out × 5M requests | $12,750/mo | $530.00/mo |
Which should you pick?
You are running this at volume
GPT-5.6 Luna
Lowest measured cost per point of capability at $0.0911 per point — the gap compounds with every request.
Quality matters more than the bill
Claude Opus 4.8
Highest overall LiveBench score of the two at 76.2.
The workload is coding or agentic work
Claude Opus 4.8
Leads on agentic coding — 50.5 against 48.4.
Claude Opus 4.8 vs GPT-5.6 Luna FAQ
Which is better, Claude Opus 4.8 or GPT-5.6 Luna?
Claude Opus 4.8 scores higher, GPT-5.6 Luna costs less — it depends on your workload. Claude Opus 4.8 is ahead by 2.7 points overall, and GPT-5.6 Luna lists 22× cheaper per blended million tokens. Whether 2.7 points is worth that depends on how much a wrong answer costs you. GPT-5.6 Luna also leads on measured cost per point of capability, at $0.0911 per point.
Is Claude Opus 4.8 cheaper than GPT-5.6 Luna?
GPT-5.6 Luna is cheaper. On a 3:1 input:output blend, Claude Opus 4.8 lists at $10.00 per million tokens and GPT-5.6 Luna at $0.450 — GPT-5.6 Luna is 22× cheaper. Input and output are priced separately — Claude Opus 4.8 charges $5.00 in and $25.00 out, GPT-5.6 Luna charges $0.200 and $1.20 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Claude Opus 4.8 vs GPT-5.6 Luna: which scores higher on benchmarks?
Claude Opus 4.8 scores 76.2 and GPT-5.6 Luna scores 73.6 overall on LiveBench, the mean of its seven categories. That is a 2.7-point lead for Claude Opus 4.8. Category scores differ from the overall figure — a model can lead on reasoning and trail on coding, which the per-category table above breaks out.
Which gives better value for money, Claude Opus 4.8 or GPT-5.6 Luna?
GPT-5.6 Luna. Cost per point divides the measured dollars LiveBench spent running the benchmark by the score it earned, so it captures something token pricing misses: a reasoning model can emit many times more tokens than its per-token rate suggests. Claude Opus 4.8 works out at $0.5347 per point and GPT-5.6 Luna at $0.0911.
Does Claude Opus 4.8 or GPT-5.6 Luna have a bigger context window?
They are effectively the same — 1M for Claude Opus 4.8 and 1.1M for GPT-5.6 Luna.
Do Claude Opus 4.8 and GPT-5.6 Luna support prompt caching?
Both publish a cached-input rate: $0.500 per million for Claude Opus 4.8 and $0.020 for GPT-5.6 Luna, against full input rates of $5.00 and $0.200. On a workload with a long stable prefix — a system prompt, a tool schema, a retrieved corpus — that changes the economics more than the headline price does.
Related comparisons
How these numbers are produced
- Price — provider list price from OpenRouter, refreshed every 15 minutes. “Blended” is a 3:1 input:output mix.
- Scores — LiveBench release 2026-06-25, using their own category map. Each model shows its strongest published run. A blank means “not evaluated”, never “bad”.
- Cost per point — the measured dollars LiveBench spent on the run, divided by the score it earned.
- “Win” — awarded only past a threshold: one full point on a benchmark score, 10% on a price, 25% on a context window. Anything tighter reports as a tie, because effort settings alone move a LiveBench score by more than that.
Published benchmarks rank models on someone else's tasks. Before committing, see LLM & agent evaluation for building an eval on your own.