Cheaper overall
GPT-6.1 Sol
50% lower blended rate
Higher benchmark scores
Claude Opus 5.5
leads on 6 of 7 figures
Bigger context window
GPT-6.1 Sol
1,050,000 vs 1,000,000 tokens
Cheaper cached input
GPT-6.1 Sol
$0.10 vs $0.20, 50% less
Where each one wins
GPT-6.1 Sol
- Cheaper input tokens $2.00 vs $4.00, 50% less
- Cheaper output tokens $10.00 vs $20.00, 50% less
- Cheaper cached input $0.10 vs $0.20, 50% less
- Cheaper on all four workloads
- Larger context window 1,050,000 tokens
- Higher answer reliability (Omniscience Non-Hallucination) 45.7 vs 41.4
- Offers Flex and Priority pricing not listed for Claude Opus 5.5
Claude Opus 5.5
- Higher overall intelligence (Intelligence Index) 57.6 vs 51.8
- Higher expert-exam performance (Humanity's Last Exam) 61.4 vs 52.9
- Higher long-context reasoning (AA-LCR) 84.7 vs 83
- Ahead on 3 more benchmark figures
What four workloads cost
One run, and the same run a thousand times.
GPT-6.1 Sol is cheaper on all four workloads, by much the same margin each time — about 1.8 times, from $0.0070 against $0.0140 on a chat turn to $1.65 against $1.66 on a long document.
| Workload | GPT-6.1 Sol | Claude Opus 5.5 | ×1,000 | Difference |
|---|---|---|---|---|
| Chat turn 1,000 in / 500 out | $0.0070 | $0.0140 | $7.00 / $14.00 | GPT-6.1 Sol is 50% cheaper |
| RAG answer 10,000 in / 800 out | $0.0280 | $0.0560 | $28.00 / $56.00 | GPT-6.1 Sol is 50% cheaper |
| Agent loop 32,000 in / 700 out × 20 calls | $0.2800 | $0.5600 | $280.00 / $560.00 | GPT-6.1 Sol is 50% cheaper |
| Long document 400,000 in / 3,000 out | $1.65 | $1.66 | $1,645.00 / $1,660.00 | GPT-6.1 Sol is 0.9% 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. It does not change which of the two is cheaper.
| Context band | Price | GPT-6.1 Sol | Claude Opus 5.5 | Difference |
|---|---|---|---|---|
| Prompts up to 272,000 tokens | Input | $2.00 | $4.00 | GPT-6.1 Sol is 50% cheaper |
| Prompts up to 272,000 tokens | Cached input | $0.10 | $0.20 | GPT-6.1 Sol is 50% cheaper |
| Prompts up to 272,000 tokens | Output | $10.00 | $20.00 | GPT-6.1 Sol is 50% cheaper |
| Prompts over 272,000 tokens | Input | $4.00 | $4.00 | Same |
| Prompts over 272,000 tokens | Cached input | $0.20 | $0.20 | Same |
| Prompts over 272,000 tokens | Output | $15.00 | $20.00 | GPT-6.1 Sol is 25% cheaper |
Blended: GPT-6.1 Sol $4.00, Claude Opus 5.5 $8.00 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 Opus 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 Opus 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 Opus 5.5 | Cheaper |
|---|---|---|---|
| Batch | $1.00 in / $5.00 out 50% off Standard | $2.00 in / $10.00 out 50% off Standard | GPT-6.1 Sol |
| 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 8 figures: GPT-6.1 Sol leads on 1, Claude Opus 5.5 on 6. The widest gap is 13.5 points, on real-world task performance (GDPval).
Overall intelligence
Intelligence Index — Overall intelligence across reasoning, knowledge & math evals
Claude Opus 5.5 ahead by 5.8
Expert-exam performance
Humanity's Last Exam — Expert-level questions across many academic domains
Claude Opus 5.5 ahead by 8.5
Long-context reasoning
AA-LCR — Long-context reasoning across large inputs
Claude Opus 5.5 ahead by 1.7
Scientific coding
SciCode — Research-level scientific coding tasks
Claude Opus 5.5 ahead by 12.7
Physics research reasoning
CritPt — Unpublished physics research reasoning problems
Level
Real-world task performance
GDPval — Economically valuable, real-world knowledge work
Claude Opus 5.5 ahead by 13.5
Factual accuracy
Omniscience Accuracy — Breadth of factual knowledge across domains
Claude Opus 5.5 ahead by 4.1
Answer reliability
Omniscience Non-Hallucination — How reliably the model avoids fabricated answers
GPT-6.1 Sol ahead by 4.3
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.
| Specification | GPT-6.1 Sol | Claude Opus 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 | 30 Jun 2026 |
| Released | 29 Sep 2026 | 22 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 | Yes |
| Computer use | Yes | Yes |
| Open weights | Not listed | Not listed |
| Reasoning | Yes | Yes |
FAQs
- Is GPT-6.1 Sol cheaper than Claude Opus 5.5?
- Yes. A 1,000-token prompt with a 500-token reply costs $0.0070 on GPT-6.1 Sol and $0.0140 on Claude Opus 5.5, and the same model is cheaper on every workload on this page.
- How much do GPT-6.1 Sol and Claude Opus 5.5 cost per 1M tokens?
- GPT-6.1 Sol costs $2.00 for input and $10.00 for output. Claude Opus 5.5 costs $4.00 and $20.00. Standard pay-as-you-go rates, as of 29 Sep 2026.
- Which is better, GPT-6.1 Sol or Claude Opus 5.5?
- On published benchmarks, Claude Opus 5.5. It leads on 6 of the 8 figures both models report, including overall intelligence (Intelligence Index), where it scores 57.6 against 51.8.
- Is Batch pricing cheaper for GPT-6.1 Sol or Claude Opus 5.5?
- Batch input costs $1.00 on GPT-6.1 Sol and $2.00 on Claude Opus 5.5, 50% below the standard rate on both.
- Does GPT-6.1 Sol or Claude Opus 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.