Claude Sonnet 5 vs GPT-5.6 Terra: Specs & Benchmark Comparison
Claude Sonnet 5 is developed by Anthropic, while GPT-5.6 Terra comes from OpenAI. Claude Sonnet 5 was released in June 2026, and GPT-5.6 Terra followed a month later in July 2026.
The two models share 10 published benchmarks. GPT-5.6 Terra leads on 6 of them, Claude Sonnet 5 on 4. The widest gaps are on GDP.pdf, where Claude Sonnet 5 scores 81.6% against 24.7%; BenchCAD, where GPT-5.6 Terra scores 62.3% against 37.3%. Averaged across everything we track, Claude Sonnet 5 sits at 58.4% and GPT-5.6 Terra at 59.0%.
On price the two are close: Claude Sonnet 5 costs $2 per million input tokens and $10 per million output tokens, GPT-5.6 Terra $2 and $12. Both accept a context window of about 1M tokens. Both accept text and images as input.
| Characteristic | Claude Sonnet 5 | GPT-5.6 Terra |
|---|---|---|
| Company | Anthropic | OpenAI |
| Release Date | June 30, 2026 | July 9, 2026 |
| Parameters | — | — |
| Multimodal | Yes | Yes |
| Context (input) | 1.0M | 1.1M |
| Context (output) | 64K | 128K |
| Input Price / 1M | $2.00 | $2.00 |
| Output Price / 1M | $10.00 | $12.00 |
| Average Score | 58.4% | 59.0% |
| Benchmarks | ||
| GDP.pdf | 81.6% | 24.7% |
| BenchCAD | 37.3% | 62.3% |
| DeepSWE 1.1 | 54.0% | 70.0% |
| Terminal-Bench 4.0 | 12.4% | 21.5% |
| BrowseComp | 84.7% | 87.5% |
| AutomationBench | 13.5% | 15.2% |
| FrontierCode 1.1 | 42.7% | 41.3% |
| Toolathlon | 54.3% | 53.1% |
| SWE-Bench Pro | 63.2% | 63.4% |
| HealthBench Professional | 57.8% | 57.7% |
Visual Benchmark Comparison
Verdict
Both models show equal results — the choice depends on your specific use case.
Both models show comparable average scores: Claude Sonnet 5 — 0.6, GPT-5.6 Terra — 0.6.
Claude Sonnet 5 is 1.2x cheaper: input $2.00/1M vs $2.00/1M tokens.
GPT-5.6 Terra supports a larger context: 1M vs 1M tokens.
Both models were released around the same time: 6/30/2026 and 7/9/2026.
More About These Models
Frequently Asked Questions
Which is better for coding — Claude Sonnet 5 or GPT-5.6 Terra?
Which model is cheaper — Claude Sonnet 5 or GPT-5.6 Terra?
Which has a larger context window — Claude Sonnet 5 or GPT-5.6 Terra?
The Claude Sonnet 5 and GPT-5.6 Terra 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-5.6 Terra page. See also the complete list of AI model comparisons.