Model comparison - Similar price, same tier
Claude Sonnet 5.5 vs GPT-6.1 Sol
Claude Sonnet 5.5 is from Anthropic and GPT-6.1 Sol is from OpenAI. Both list the same first-party API price: $2 per 1M input tokens and $10 per 1M output tokens. Claude Sonnet 5.5 has a 1,000,000-token context window and GPT-6.1 Sol 1,050,000 tokens, and both return up to 128,000 output tokens per response. Claude Sonnet 5.5 was released on September 28, 2026 and GPT-6.1 Sol on September 29, 2026. Both are closed-weights models, available only through an API.
Last verified from each provider's pricing page. All sources
Side-by-side specs
| Spec | Claude Sonnet 5.5 | GPT-6.1 Sol |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input / 1M tokens | $2 | $2 |
| Output / 1M tokens | $10 | $10 |
| Cache read / 1M | $0.10 | $0.10 |
| Cache write / 1M | $2.50 | $2.50 |
| Batch input / 1M | $1 | $1 |
| Batch output / 1M | $5 | $5 |
| Long-context rates above | - | 272,000 tokens |
| Context window | 1,000,000 | 1,050,000 |
| Max output | 128,000 | 128,000 |
| Release date | ||
| Weights | Closed | Closed |
| API model id | claude-sonnet-5-5 | gpt-6.1-sol |
| AI Gateway id | anthropic/claude-sonnet-5.5 | openai/gpt-6.1-sol |
| Last verified |
Prices in USD per 1M tokens at each provider's standard first-party rate. A dash means the provider does not bill that item separately or no primary page states it.
What each costs in practice
The same three workloads every model page uses, worked from each model's standard list rates. Swap in your own token counts with the math on each model's page.
| Workload | Claude Sonnet 5.5 | GPT-6.1 Sol |
|---|---|---|
| One agent session1M input tokens and 100K output tokens, no caching. | $3.00 | $3.00 |
| A chat app10,000 requests a day at 2K input and 500 output tokens each. | $90.00$2,700.00 per 30-day month | $90.00$2,700.00 per 30-day month |
| The same session at a 90% cache hit90% of the input is read from the prompt cache. The one-time cache write premium is not included. | $1.29 | $1.29 |
Show the math
Claude Sonnet 5.5
- One agent sessionInput: 1M x $2 = $2.00Output: 0.1M x $10 = $1.00
- A chat appInput: 20M x $2 = $40.00Output: 5M x $10 = $50.00
- The same session at a 90% cache hitCached input: 0.9M x $0.10 = $0.09Uncached input: 0.1M x $2 = $0.20Output: 0.1M x $10 = $1.00
GPT-6.1 Sol
- One agent sessionInput: 1M x $2 = $2.00Output: 0.1M x $10 = $1.00
- A chat appInput: 20M x $2 = $40.00Output: 5M x $10 = $50.00
- The same session at a 90% cache hitCached input: 0.9M x $0.10 = $0.09Uncached input: 0.1M x $2 = $0.20Output: 0.1M x $10 = $1.00
Benchmarks under the same setting
No board in the benchmark directory lists both Claude Sonnet 5.5 and GPT-6.1 Sol under the same setting, so there is no like-for-like score to show here.
Set them up in your tools
Step-by-step guides whose official docs list Claude Sonnet 5.5 or GPT-6.1 Sol by model id.
Model pages
FAQ
How do Claude Sonnet 5.5 and GPT-6.1 Sol compare on price?
Both list the same first-party API price: $2 per 1M input tokens and $10 per 1M output tokens. For one agent session of 1M input and 100K output tokens with no caching, that is $3.00 on Claude Sonnet 5.5 and $3.00 on GPT-6.1 Sol. Prices are each provider's first-party list rates, verified October 17, 2026 and October 17, 2026.
What are the context windows of Claude Sonnet 5.5 and GPT-6.1 Sol?
Claude Sonnet 5.5 has a 1,000,000-token context window and GPT-6.1 Sol 1,050,000 tokens, and both return up to 128,000 output tokens per response.
Are Claude Sonnet 5.5 and GPT-6.1 Sol open weights?
Claude Sonnet 5.5 is closed-weights and is called through Anthropic's API as claude-sonnet-5-5. GPT-6.1 Sol is closed-weights and is called through OpenAI's API as gpt-6.1-sol.
More comparisons
- Claude Sonnet 5.5 vs Gemini 4 ArgonSimilar price, same tier
- Gemini 4 Argon vs GPT-6.1 SolSimilar price, same tier
- Claude Sonnet 5.5 vs Grok 4.7Similar price, same tier
- Claude Opus 5.5 vs GPT-6.1 SolSimilar price, same tier
- Claude Sonnet 5.5 vs GLM-5.3Open weights vs closed
- GPT-6.1 Sol vs GPT-6 SolSame provider, successor
- Claude Sonnet 5.5 vs Qwen3.8-2.4T-A95BSimilar price, same tier
- GPT-6.1 Sol vs Grok 4.7Similar price, same tier
Sources
Claude Sonnet 5.5 verified from platform.claude.com; GPT-6.1 Sol verified from developers.openai.com. This page is as current as the older of the two: .
- https://platform.claude.com/docs/en/about-claude/pricing
- https://developers.openai.com/api/docs/pricing
- https://platform.claude.com/docs/en/models/sonnet-5-5/overview
- https://platform.claude.com/docs/en/about-claude/models/overview
- https://platform.claude.com/docs/en/release-notes/overview
- https://developers.openai.com/api/docs/models/gpt-6.1-sol
- https://developers.openai.com/api/docs/changelog
Newsletter
Get model price changes as they ship
One email per week. New model releases, price cuts and what they mean for your bill.