Blended rate
Same for both
$4.00 per 1M each
Cheaper on long prompts
Claude Sonnet 5.5
above 272,000 input tokens
Higher benchmark scores
Claude Sonnet 5.5
leads on 10 of 14 figures
Bigger context window
GPT-6.1 Sol
1,050,000 vs 1,000,000 tokens
Where each one wins
GPT-6.1 Sol
- Larger context window 1,050,000 tokens
- Higher long-context reasoning (AA-LCR) 84 vs 82.7
- Higher physics research reasoning (CritPt) 31.7 vs 31.4
- Higher factual accuracy (Omniscience Accuracy) 62.1 vs 53.9
- Ahead on 1 more benchmark figure
- Offers Flex and Priority pricing not listed for Claude Sonnet 5.5
Claude Sonnet 5.5
- Cheaper on all four workloads
- Cheaper on long prompts above 272,000 input tokens
- Higher overall intelligence (Intelligence Index) 56 vs 51.8
- Higher expert-exam performance (Humanity's Last Exam) 55 vs 52.9
- Higher scientific coding (SciCode) 61 vs 55.8
- Ahead on 7 more benchmark figures
What four workloads cost
One run, and the same run a thousand times.
They cost the same on a chat turn and a RAG answer and an agent loop, so the difference only shows up further down: on a long document, Claude Sonnet 5.5 costs $0.8300 against $1.65.
| Workload | GPT-6.1 Sol | Claude Sonnet 5.5 | ×1,000 | Difference |
|---|---|---|---|---|
| Chat turn 1,000 in / 500 out | $0.0070 | $0.0070 | $7.00 / $7.00 | Same |
| RAG answer 10,000 in / 800 out | $0.0280 | $0.0280 | $28.00 / $28.00 | Same |
| Agent loop 32,000 in / 700 out × 20 calls | $0.2800 | $0.2800 | $280.00 / $280.00 | Same |
| Long document 400,000 in / 3,000 out | $1.65 | $0.8300 | $1,645.00 / $830.00 | Claude Sonnet 5.5 is 50% cheaper |
Price per 1M tokens
Above 272,000 input tokens the rates change, and the new rate applies to the whole request, not just the tokens past that point: GPT-6.1 Sol's input goes from $2.00 to $4.00. That is where the cheaper model changes.
| Context band | Price | GPT-6.1 Sol | Claude Sonnet 5.5 | Difference |
|---|---|---|---|---|
| Prompts up to 272,000 tokens | Input | $2.00 | $2.00 | Same |
| Prompts up to 272,000 tokens | Cached input | $0.10 | $0.10 | Same |
| Prompts up to 272,000 tokens | Output | $10.00 | $10.00 | Same |
| Prompts over 272,000 tokens | Input | $4.00 | $2.00 | Claude Sonnet 5.5 is 50% cheaper |
| Prompts over 272,000 tokens | Cached input | $0.20 | $0.10 | Claude Sonnet 5.5 is 50% cheaper |
| Prompts over 272,000 tokens | Output | $15.00 | $10.00 | Claude Sonnet 5.5 is 33% cheaper |
Blended: GPT-6.1 Sol $4.00, Claude Sonnet 5.5 $4.00 per 1M — one rate at 3:1 input to output, for comparing two models at a glance.
GPT-6.1 Sol priced by OpenAI, Claude Sonnet 5.5 by Anthropic. Standard tier, pay-as-you-go.
Other pricing tiers
Both models offer Batch, worth up to 50% off their standard rates, and the cheaper model is the same one on every tier — so the tier you buy changes the bill rather than the choice. Only GPT-6.1 Sol lists Flex and Priority, at up to 50% off its own standard rate; Claude Sonnet 5.5 offers none of them.
Every tier either model sells is here, so this is the whole price sheet. A saving is measured against that model's own standard rate — how we read tiers.
| Tier | GPT-6.1 Sol | Claude Sonnet 5.5 | Cheaper |
|---|---|---|---|
| Batch | $1.00 in / $5.00 out 50% off Standard | $1.00 in / $5.00 out 50% off Standard | Same |
| Flex only on GPT-6.1 Sol | $1.00 in / $5.00 out 50% off Standard | Not offered | — |
| Priority only on GPT-6.1 Sol | $4.00 in / $20.00 out | Not offered | — |
Benchmarks
They share 14 figures: GPT-6.1 Sol leads on 4, Claude Sonnet 5.5 on 10. The widest gap is 90 points, on Gamedev Elo.
Overall intelligence
Intelligence Index — Overall intelligence across reasoning, knowledge & math evals
Claude Sonnet 5.5 ahead by 4.2
Expert-exam performance
Humanity's Last Exam — Expert-level questions across many academic domains
Claude Sonnet 5.5 ahead by 2.1
Long-context reasoning
AA-LCR — Long-context reasoning across large inputs
GPT-6.1 Sol ahead by 1.3
Scientific coding
SciCode — Research-level scientific coding tasks
Claude Sonnet 5.5 ahead by 5.2
Physics research reasoning
CritPt — Unpublished physics research reasoning problems
GPT-6.1 Sol ahead by 0.3
Real-world task performance
GDPval — Economically valuable, real-world knowledge work
Claude Sonnet 5.5 ahead by 12.2
Factual accuracy
Omniscience Accuracy — Breadth of factual knowledge across domains
GPT-6.1 Sol ahead by 8.2
Answer reliability
Omniscience Non-Hallucination — How reliably the model avoids fabricated answers
Claude Sonnet 5.5 ahead by 2.4
3d Elo
Design Arena head-to-head rating in the 3d category
GPT-6.1 Sol ahead by 5
Codecategories Elo
Design Arena head-to-head rating in the codecategories category
Claude Sonnet 5.5 ahead by 23
Dataviz Elo
Design Arena head-to-head rating in the dataviz category
Claude Sonnet 5.5 ahead by 60
Gamedev Elo
Design Arena head-to-head rating in the gamedev category
Claude Sonnet 5.5 ahead by 90
Uicomponent Elo
Design Arena head-to-head rating in the uicomponent category
Claude Sonnet 5.5 ahead by 25
Website Elo
Design Arena head-to-head rating in the website category
Claude Sonnet 5.5 ahead by 11
Each figure is that model's best published run, with the effort level named beside it — where these scores come from.
Specifications
GPT-6.1 Sol holds 50,000 more input tokens in one request. Only GPT-6.1 Sol lists web search, code execution and computer use.
| Specification | GPT-6.1 Sol | Claude Sonnet 5.5 |
|---|---|---|
| Context window | 1,050,000 tokens | 1,000,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Takes in | Text, image, file | Text, image, file |
| Puts out | Text | Text |
| Knowledge cutoff | 30 Apr 2026 | — |
| Released | 29 Sep 2026 | 28 Sep 2026 |
| Status | Active | Active |
| Sold by | OpenAI, Perplexity | Anthropic, Perplexity |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Web search | Yes | Not listed |
| Prompt caching | Yes | Yes |
| Code execution | Yes | Not listed |
| Computer use | Yes | Not listed |
| Open weights | Not listed | Not listed |
| Reasoning | Yes | Yes |
FAQs
- Is GPT-6.1 Sol cheaper than Claude Sonnet 5.5?
- They cost the same on a typical exchange: 1,000 input tokens with a 500-token reply comes to $0.0070 on either.
- How much do GPT-6.1 Sol and Claude Sonnet 5.5 cost per 1M tokens?
- GPT-6.1 Sol costs $2.00 for input and $10.00 for output. Claude Sonnet 5.5 costs $2.00 and $10.00. Standard pay-as-you-go rates, as of 8 Oct 2026.
- Which is better, GPT-6.1 Sol or Claude Sonnet 5.5?
- On published benchmarks, Claude Sonnet 5.5. It leads on 10 of the 14 figures both models report, including overall intelligence (Intelligence Index), where it scores 56 against 51.8.
- Is GPT-6.1 Sol or Claude Sonnet 5.5 cheaper for long prompts?
- Claude Sonnet 5.5, above 272,000 input tokens. A rate that changes at a context length applies to the whole request, not only the tokens past it, so the switch is sharp rather than gradual.
- Is Batch pricing cheaper for GPT-6.1 Sol or Claude Sonnet 5.5?
- Batch input costs $1.00 on GPT-6.1 Sol and $1.00 on Claude Sonnet 5.5, 50% below the standard rate on both.
- Does GPT-6.1 Sol or Claude Sonnet 5.5 have a bigger context window?
- GPT-6.1 Sol, at 1,050,000 tokens against 1,000,000. That is 50,000 more input tokens in a single request.