Claude Opus 5.5 vs GPT-6.1 Sol: Specs & Benchmark Comparison
Claude Opus 5.5 is developed by Anthropic, while GPT-6.1 Sol comes from OpenAI. Both were released in September 2026.
The two models share 5 published benchmarks. Claude Opus 5.5 leads on 4 of them, GPT-6.1 Sol on 1. The widest gaps are on OSWorld 2.0, where Claude Opus 5.5 scores 81.8% against 71.4%; HealthBench, where Claude Opus 5.5 scores 60.6% against 58.5%. Averaged across everything we track, Claude Opus 5.5 sits at 71.1% and GPT-6.1 Sol at 58.5%.
GPT-6.1 Sol is the cheaper API at $2 per million input tokens and $10 per million output tokens, roughly 2 times cheaper than Claude Opus 5.5 at $4 and $20. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Claude Opus 5.5 | GPT-6.1 Sol |
|---|---|---|
| Company | Anthropic | OpenAI |
| Release Date | September 22, 2026 | September 29, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.1M |
| Context (output) | 128K | 128K |
| Input Price / 1M | $4.00 | $2.00 |
| Output Price / 1M | $20.00 | $10.00 |
| Average Score | 71.1% | 58.5% |
| Benchmarks | ||
| OSWorld 2.0 | 81.8% | 71.4% |
| HealthBench | 60.6% | 58.5% |
| Terminal-Bench-Science 0.1 | 58.7% | 57.0% |
| HealthBench Professional | 65.6% | 64.2% |
| DeepSWE 1.1 | 74.2% | 75.2% |
Visual Benchmark Comparison
Verdict
GPT-6.1 Sol leads in 2 out of 4 comparison categories.
Both models show comparable average scores: Claude Opus 5.5 — 0.7, GPT-6.1 Sol — 0.6.
GPT-6.1 Sol is 2.0x cheaper: input $2.00/1M vs $4.00/1M tokens.
GPT-6.1 Sol supports a larger context: 1M vs 1M tokens.
Both models were released around the same time: 9/22/2026 and 9/29/2026.
More About These Models
Related Comparisons
Frequently Asked Questions
Which is better for coding — Claude Opus 5.5 or GPT-6.1 Sol?
Which model is cheaper — Claude Opus 5.5 or GPT-6.1 Sol?
Which has a larger context window — Claude Opus 5.5 or GPT-6.1 Sol?
The Claude Opus 5.5 and GPT-6.1 Sol comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Opus 5.5 or GPT-6.1 Sol page. See also the complete list of AI model comparisons.