Claude Opus 5.5 vs GPT-6.1 Sol
Claude Opus 5.5 costs $4.00 / $20.00 and GPT-6.1 Sol costs $2.00 / $10.00 per million input / output tokens. At a typical 3:1 mix, GPT-6.1 Sol is 2.0× cheaper than Claude Opus 5.5.
Claude Opus 5.5
Anthropic
Input
$4.00
per 1M
Output
$20.00
per 1M
Cached
$0.20
1M context
Input
$2.00
per 1M
Output
$10.00
per 1M
Cached
$0.10
1.05M context
Side by side
Green marks the cheaper price, larger context window, bigger discount or higher score.
| Detail | Claude Opus 5.5 | GPT-6.1 Sol |
|---|---|---|
| Input per 1M | $4.00 | $2.00 |
| Output per 1M | $20.00 | $10.00 |
| Blended per 1M (3:1) | $8.00 | $4.00 |
| Cached input per 1M | $0.20 | $0.10 |
| Batch or off-peak discount | 50% (batch) | 50% (batch) |
| Long prompts | Same rate at any length | Over 272K: 2× in, 1.5× out |
| Context window | 1M | 1.05M |
| Released | 22 Sep 2026 | 29 Sep 2026 |
| Open weights | No | No |
| Arena text score | 1509 | — |
| Verified | 27 Sep 2026 | 2 Oct 2026 |
Sources: Anthropic pricing and OpenAI model page.
Monthly cost on three workloads
List prices, no batch discount. The cached share applies where a model has a cache rate.
| Workload | Claude Opus 5.5 | GPT-6.1 Sol | Difference |
|---|---|---|---|
| Customer chat assistant50,000 conversations a month, about 2,000 tokens in and 400 out each; 50% cached | $610 | $305 | $305 |
| Document Q&A (RAG)20,000 questions a month over retrieved documents, 12,000 in and 600 out; 30% cached | $926 | $463 | $463 |
| Coding agent400 tasks a month, 40 steps each with a growing context; 85% cached | $738 | $369 | $369 |
How they differ
- GPT-6.1 Sol is cheaper on input ($2 vs $4).
- GPT-6.1 Sol is cheaper on output ($10 vs $20), which matters most for long answers and reasoning models.
- GPT-6.1 Sol accepts longer prompts (1.05M vs 1M tokens).
- Cached input is cheaper on GPT-6.1 Sol ($0.10 vs $0.20), which favours agents and chat apps that resend the same context.
Recent changes
All changes- GPT-6.1 Sol replaced GPT-6 Sol at the same $2 / $10 per 1M tokens, with cached input cut from $0.20 to $0.10.
- ▼ 20%Claude Opus 5.5 launched at $4 / $20 per 1M tokens, 20% below Opus 5.
- OpenAI launched GPT-6 Sol at $2 / $10 and GPT-6 Luna at $0.10 / $0.50.
- OpenAI launched GPT-6 Astra at $10 / $50, its most expensive standard model.
- Anthropic retired Claude Opus 4.1.
Related comparisons
Compare any two- Claude Opus 5.5 vs GPT-6 Astra$4.00 / $20.00 · $10.00 / $50.00
- Claude Sonnet 5.5 vs GPT-6.1 Sol$2.00 / $10.00 · $2.00 / $10.00
Gemini 3.8 Flash vs GPT-6.1 Sol$0.75 / $3.75 · $2.00 / $10.00
Grok 4.7 vs GPT-6.1 Sol$2.00 / $6.00 · $2.00 / $10.00
Kimi K3 vs Claude Opus 5.5$3.00 / $15.00 · $4.00 / $20.00
Qwen3.8 Max vs GPT-6.1 Sol$2.00 / $6.00 · $2.00 / $10.00- Claude Opus 5.5 vs Gemini 3.1 Pro$4.00 / $20.00 · $2.00 / $12.00
- Grok 4.7 vs Claude Opus 5.5$2.00 / $6.00 · $4.00 / $20.00
Muse Spark 1.3 vs GPT-6.1 Sol$1.25 / $4.25 · $2.00 / $10.00