// head_to_head
Claude Sonnet 5 vs GPT-5.5
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.
GPT-5.5 scores higher, Claude Sonnet 5 costs less — it depends on your workload.
GPT-5.5 is ahead by 4.1 points overall, and Claude Sonnet 5 lists 2.8× cheaper per blended million tokens. Whether 4.1 points is worth that depends on how much a wrong answer costs you.
anthropic
Claude Sonnet 5
- Blended / 1M
- $4.00
- Context
- 1M
- Released
- Jun 30, 2026
- Overall score
- 76.0
openai
GPT-5.5
- Blended / 1M
- $11.25
- Context
- 1.1M
- Released
- Apr 24, 2026
- Overall score
- 80.2
Specs and pricing
| Metric | Claude Sonnet 5 | GPT-5.5 |
|---|---|---|
| LiveBench overall Mean of the seven LiveBench category scores, 0–100. Higher is better. | 76.0 | 80.2win |
| Cost per point Measured benchmark spend divided by overall score — dollars per point of capability. | $0.2691 | $0.2417 |
| Blended price / 1M 3:1 input:output mix, the usual shape of production traffic. | $4.00win | $11.25 |
| Input price / 1M | $2.00win | $5.00 |
| Output price / 1M | $10.00win | $30.00 |
| Cached input / 1M Price of an input token served from the prompt cache, where the provider publishes one. | $0.200win | $0.500 |
| 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 Sonnet 5 on top, GPT-5.5 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 Sonnet 5 | GPT-5.5 |
|---|---|---|
| Support chatbot 1.2K in / 400 out × 200K requests | $1150.40/mo | $3276.00/mo |
| RAG assistant 8K in / 600 out × 100K requests | $1480.00/mo | $4000.00/mo |
| Coding agent 40K in / 4K out × 20K requests | $1392.00/mo | $3880.00/mo |
| Document extraction 20K in / 1.5K out × 50K requests | $2660.00/mo | $7025.00/mo |
| Bulk classification 500 in / 20 out × 5M requests | $5100.00/mo | $13,250/mo |
Which should you pick?
Quality matters more than the bill
GPT-5.5
Highest overall LiveBench score of the two at 80.2.
The workload is coding or agentic work
Claude Sonnet 5
Leads on agentic coding — 59.4 against 54.0.
Claude Sonnet 5 vs GPT-5.5 FAQ
Which is better, Claude Sonnet 5 or GPT-5.5?
GPT-5.5 scores higher, Claude Sonnet 5 costs less — it depends on your workload. GPT-5.5 is ahead by 4.1 points overall, and Claude Sonnet 5 lists 2.8× cheaper per blended million tokens. Whether 4.1 points is worth that depends on how much a wrong answer costs you.
Is Claude Sonnet 5 cheaper than GPT-5.5?
Claude Sonnet 5 is cheaper. On a 3:1 input:output blend, Claude Sonnet 5 lists at $4.00 per million tokens and GPT-5.5 at $11.25 — Claude Sonnet 5 is 2.8× cheaper. Input and output are priced separately — Claude Sonnet 5 charges $2.00 in and $10.00 out, GPT-5.5 charges $5.00 and $30.00 — so the model that looks cheaper flips depending on how output-heavy your workload is.
Claude Sonnet 5 vs GPT-5.5: which scores higher on benchmarks?
Claude Sonnet 5 scores 76.0 and GPT-5.5 scores 80.2 overall on LiveBench, the mean of its seven categories. That is a 4.1-point lead for GPT-5.5. 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 Sonnet 5 or GPT-5.5?
They are close. Claude Sonnet 5 costs $0.2691 per point of overall capability and GPT-5.5 costs $0.2417, a difference small enough that workload shape will matter more than the rate.
Does Claude Sonnet 5 or GPT-5.5 have a bigger context window?
They are effectively the same — 1M for Claude Sonnet 5 and 1.1M for GPT-5.5.
Do Claude Sonnet 5 and GPT-5.5 support prompt caching?
Both publish a cached-input rate: $0.200 per million for Claude Sonnet 5 and $0.500 for GPT-5.5, against full input rates of $2.00 and $5.00. 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.