Claude Sonnet 5 vs GPT-5.6 Terra

Claude Sonnet 5 and GPT-5.6 Terra are both current production-tier models. Claude Sonnet 5 leads on long-context retrieval.

Specs side by side

Metric
Anthropic
Claude Sonnet 5
OpenAI
GPT-5.6 Terra
Input price (per 1M)$3$2.5
Output price (per 1M)$15$15
Context window1M tokens1.1M tokens
Speed tierbalancedbalanced
Open weightsNoNo
EU regionYesYes
Free tierNoNo
Prompt cachingYesYes
Vision inputYesYes
Extended thinkingYesYes

When to choose each

Anthropic

Choose Claude Sonnet 5 if…

  • Long-context retrieval is central to your workload
OpenAI

Choose GPT-5.6 Terra if…

  • GPT-5.6 Terra is in the same tier as Claude Sonnet 5 — pick by provider preference or API ecosystem

Benchmark delta

Claude Sonnet 5 leads on

  • Long-context retrieval

GPT-5.6 Terra leads on

GPT-5.6 Terra has no meaningful benchmark lead in this pair.

FAQ — Claude Sonnet 5 vs GPT-5.6 Terra

Claude Sonnet 5 vs GPT-5.6 Terra — which is better?

Claude Sonnet 5 and GPT-5.6 Terra are both current production-tier models. Claude Sonnet 5 leads on long-context retrieval. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does Claude Sonnet 5 pricing compare to GPT-5.6 Terra?

Claude Sonnet 5 costs $3 / $15 per 1M vs GPT-5.6 Terra at $2.5 / $15 per 1M. GPT-5.6 Terra is cheaper on input tokens by roughly 0%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does Claude Sonnet 5 or GPT-5.6 Terra have the bigger context window?

GPT-5.6 Terra has a 1.1M-token context window — 1× the 1M context of Claude Sonnet 5. Enough for entire codebases, books, or multi-document RAG.

Is there a free tier for Claude Sonnet 5 or GPT-5.6 Terra?

Claude Sonnet 5: no — Default model on Claude.ai Free/Pro web chat; API requires paid credits. GPT-5.6 Terra: no — Free $5 credit for new accounts; paid thereafter.

Which is better for coding — Claude Sonnet 5 or GPT-5.6 Terra?

Claude Sonnet 5 leads on coding benchmarks (Claude Sonnet 5: 95/100, GPT-5.6 Terra: 93/100). For production coding agents also weigh tool-use performance — Claude Sonnet 5 scores 96, GPT-5.6 Terra scores 93.