Claude Sonnet 5 vs GPT-5.1 Codex High: Specs & Benchmark Comparison
| Characteristic | Claude Sonnet 5 | GPT-5.1 Codex High |
|---|---|---|
| Company | Anthropic | OpenAI |
| Release Date | June 30, 2026 | November 11, 2025 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 400K |
| Context (output) | 64K | 128K |
| Input Price / 1M | $2.00 | $1.25 |
| Output Price / 1M | $10.00 | $10.00 |
| Average Score | 0.6 | 1.0 |
Verdict
Claude Sonnet 5 leads in 2 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: Claude Sonnet 5 — 0.6, GPT-5.1 Codex High — 1.0.
API Cost
GPT-5.1 Codex High is 1.1x cheaper: input $1.25/1M vs $2.00/1M tokens.
Context Window
Claude Sonnet 5 supports a larger context: 1M vs 400K tokens.
Recency
Claude Sonnet 5 is newer: released 6/30/2026 vs 11/11/2025.
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Frequently Asked Questions
Which is better for coding — Claude Sonnet 5 or GPT-5.1 Codex High?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — Claude Sonnet 5 or GPT-5.1 Codex High?
GPT-5.1 Codex High is cheaper for input: $1.25 per 1M tokens vs $2.00.
Which has a larger context window — Claude Sonnet 5 or GPT-5.1 Codex High?
Claude Sonnet 5 supports a larger context: 1,000,000 tokens vs 400,000.
The Claude Sonnet 5 and GPT-5.1 Codex High comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the Claude Sonnet 5 or GPT-5.1 Codex High page. See also the complete list of AI model comparisons.