Claude 3.5 Sonnet vs GPT-5.1 Codex High: Specs & Benchmark Comparison
| Characteristic | Claude 3.5 Sonnet | GPT-5.1 Codex High |
|---|---|---|
| Company | Anthropic | OpenAI |
| Release Date | June 21, 2024 | November 11, 2025 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 200K | 400K |
| Context (output) | 200K | 128K |
| Input Price / 1M | $3.00 | $1.25 |
| Output Price / 1M | $15.00 | $10.00 |
| Average Score | 0.8 | 1.0 |
Verdict
GPT-5.1 Codex High leads in 3 out of 4 comparison categories.
Overall Performance
Both models show comparable average scores: Claude 3.5 Sonnet — 0.8, GPT-5.1 Codex High — 1.0.
API Cost
GPT-5.1 Codex High is 1.6x cheaper: input $1.25/1M vs $3.00/1M tokens.
Context Window
GPT-5.1 Codex High supports a larger context: 400K vs 200K tokens.
Recency
GPT-5.1 Codex High is newer: released 11/11/2025 vs 6/21/2024.
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Frequently Asked Questions
Which is better for coding — Claude 3.5 Sonnet 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 3.5 Sonnet or GPT-5.1 Codex High?
GPT-5.1 Codex High is cheaper for input: $1.25 per 1M tokens vs $3.00.
Which has a larger context window — Claude 3.5 Sonnet or GPT-5.1 Codex High?
GPT-5.1 Codex High supports a larger context: 400,000 tokens vs 200,000.
The Claude 3.5 Sonnet 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 3.5 Sonnet or GPT-5.1 Codex High page. See also the complete list of AI model comparisons.