Model comparison - Similar price, same tier
Claude Opus 5.5 vs GPT-6.1 Sol
Claude Opus 5.5 is from Anthropic and GPT-6.1 Sol is from OpenAI. On list price, Claude Opus 5.5 charges 2x GPT-6.1 Sol's input price ($4 vs $2 per 1M tokens), and Claude Opus 5.5 charges 2x GPT-6.1 Sol's output price ($20 vs $10 per 1M tokens). Claude Opus 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 Opus 5.5 was released on September 22, 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 Opus 5.5 | GPT-6.1 Sol |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Input / 1M tokens | $4 | $2 |
| Output / 1M tokens | $20 | $10 |
| Cache read / 1M | $0.20 | $0.10 |
| Cache write / 1M | $5 | $2.50 |
| Batch input / 1M | $2 | $1 |
| Batch output / 1M | $10 | $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-opus-5-5 | gpt-6.1-sol |
| AI Gateway id | anthropic/claude-opus-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 Opus 5.5 | GPT-6.1 Sol |
|---|---|---|
| One agent session1M input tokens and 100K output tokens, no caching. | $6.00 | $3.00 |
| A chat app10,000 requests a day at 2K input and 500 output tokens each. | $180.00$5,400.00 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. | $2.58 | $1.29 |
Show the math
Claude Opus 5.5
- One agent sessionInput: 1M x $4 = $4.00Output: 0.1M x $20 = $2.00
- A chat appInput: 20M x $4 = $80.00Output: 5M x $20 = $100.00
- The same session at a 90% cache hitCached input: 0.9M x $0.20 = $0.18Uncached input: 0.1M x $4 = $0.40Output: 0.1M x $20 = $2.00
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
Only boards that list both models under the same run setting appear here, one row per board and setting, with each score exactly as the board shows it. Scores on different boards use different scales and are never combined.
| Board and setting | Claude Opus 5.5 | GPT-6.1 Sol |
|---|---|---|
| ARC-AGI-2reasoning level: MaxOfficial leaderboard - arcprize.org | 91.7% | 94.2% |
| ARC-AGI-2reasoning level: HighOfficial leaderboard - arcprize.org | 93.3% | 91.7% |
| ARC-AGI-2reasoning level: XHighOfficial leaderboard - arcprize.org | 92.5% | 91.7% |
| LMArena Text (Text Arena Overall)Text Arena Overall, default leaderboard view (8,834,211 votes, 416 models)Official leaderboard - arena.ai | 1508±7 | 1484±8 |
| LMArena WebDev (Code Arena WebDev Overall)Code Arena WebDev Overall, default leaderboard view (891,922 votes, 145 models)Official leaderboard - arena.ai | 1807+14/-14 | 1755+13/-13 |
Set them up in your tools
Step-by-step guides whose official docs list Claude Opus 5.5 or GPT-6.1 Sol by model id.
Model pages
FAQ
How do Claude Opus 5.5 and GPT-6.1 Sol compare on price?
On list price, Claude Opus 5.5 charges 2x GPT-6.1 Sol's input price ($4 vs $2 per 1M tokens), and Claude Opus 5.5 charges 2x GPT-6.1 Sol's output price ($20 vs $10 per 1M tokens). For one agent session of 1M input and 100K output tokens with no caching, that is $6.00 on Claude Opus 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 Opus 5.5 and GPT-6.1 Sol?
Claude Opus 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 Opus 5.5 and GPT-6.1 Sol open weights?
Claude Opus 5.5 is closed-weights and is called through Anthropic's API as claude-opus-5-5. GPT-6.1 Sol is closed-weights and is called through OpenAI's API as gpt-6.1-sol.
More comparisons
- Claude Opus 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 GPT-6.1 SolSimilar price, same tier
- Claude Opus 5.5 vs Grok 4.7Similar price, same tier
- Claude Opus 5.5 vs GLM-5.3Open weights vs closed
- GPT-6.1 Sol vs GPT-6 SolSame provider, successor
- Claude Opus 5.5 vs Qwen3.8-2.4T-A95BSimilar price, same tier
- GPT-6.1 Sol vs Grok 4.7Similar price, same tier
Sources
Claude Opus 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/opus-5-5/overview
- https://platform.claude.com/docs/en/about-claude/models/overview
- https://platform.claude.com/docs/en/release-notes/overview
- https://platform.claude.com/docs/en/build-with-claude/fast-mode
- https://developers.openai.com/api/docs/models/gpt-6.1-sol
- https://developers.openai.com/api/docs/changelog
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