Claude Opus 4.1 vs GPT-5.1
Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.
Claude Opus 4.1
Anthropic · Aug 2025
The last $15/$75-priced Opus — a 2025 flagship now thoroughly superseded by cheaper, stronger successors.
GPT-5.1
59.6OpenAI · Nov 2025
A November 2025 update to GPT-5 with adaptive reasoning that spends thinking tokens only when a task needs them.
The verdict
GPT-5.1 wins 1 of the 1 benchmarks these models share, against 0 for Claude Opus 4.1. On price the gap is dramatic: GPT-5.1 works out roughly 8.7x cheaper per blended million tokens. GPT-5.1 also takes 400K of context versus 200K for Claude Opus 4.1.
Benchmark head-to-head 0–1
Specs & pricing
| Claude Opus 4.1 | GPT-5.1 | |
|---|---|---|
| modhub Index | — | 59.6 |
| Input price / 1M | $15 | $1.25 |
| Output price / 1M | $75 | $10 |
| Context window | 200K | 400K |
| Max output | 32K | 128K |
| Open weights | no | no |
| Reasoning model | yes | yes |
| Multimodal input | text, image | text, image |
| Knowledge cutoff | Mar 2025 | Sep 2024 |
| Released | Aug 2025 | Nov 2025 |
| Example monthly cost* | $262.50 | $27.50 |
* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.
Frequently asked questions
- Which is better, Claude Opus 4.1 or GPT-5.1?
- GPT-5.1 wins 1 of the 1 benchmarks these models share, against 0 for Claude Opus 4.1. On price the gap is dramatic: GPT-5.1 works out roughly 8.7x cheaper per blended million tokens. GPT-5.1 also takes 400K of context versus 200K for Claude Opus 4.1.
- Which is cheaper, Claude Opus 4.1 or GPT-5.1?
- Claude Opus 4.1 costs $15/$75 per million input/output tokens, while GPT-5.1 costs $1.25/$10. For a typical workload of 10M input and 1.5M output tokens per month, that's $262.50 versus $27.50.
- Which model is better for coding, Claude Opus 4.1 or GPT-5.1?
- On SWE-bench Verified — the standard agentic-coding benchmark — GPT-5.1 scores 76.3% versus 74.5% for Claude Opus 4.1, making GPT-5.1 the stronger pick for coding agents.