GPT-5.6 Sol vs GPT-5.6 Terra

GPT-5.6 Sol and GPT-5.6 Terra are both current openai production-tier models. GPT-5.6 Terra is meaningfully cheaper at $2.5 / $15 per 1M.

Specs side by side

Metric
OpenAI
GPT-5.6 Sol
OpenAI
GPT-5.6 Terra
Input price (per 1M)$5$2.5
Output price (per 1M)$30$15
Context window1.1M tokens1.1M tokens
Speed tierbalancedbalanced
Open weightsNoNo
EU regionYesYes
Free tierNoNo
Prompt cachingYesYes
Vision inputYesYes
Extended thinkingYesYes

When to choose each

OpenAI

Choose GPT-5.6 Sol if…

  • You need realtime speech-to-speech
OpenAI

Choose GPT-5.6 Terra if…

  • Cost is a priority ($2.5 / $15 per 1M vs $5 / $30 per 1M)

Benchmark delta

GPT-5.6 Sol leads on

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

GPT-5.6 Terra leads on

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

FAQ — GPT-5.6 Sol vs GPT-5.6 Terra

GPT-5.6 Sol vs GPT-5.6 Terra — which is better?

GPT-5.6 Sol and GPT-5.6 Terra are both current openai production-tier models. GPT-5.6 Terra is meaningfully cheaper at $2.5 / $15 per 1M. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.

How does GPT-5.6 Sol pricing compare to GPT-5.6 Terra?

GPT-5.6 Sol costs $5 / $30 per 1M vs GPT-5.6 Terra at $2.5 / $15 per 1M. GPT-5.6 Terra is cheaper on output tokens by roughly 100%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.

Does GPT-5.6 Sol or GPT-5.6 Terra have the bigger context window?

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

Is there a free tier for GPT-5.6 Sol or GPT-5.6 Terra?

GPT-5.6 Sol: no — Paid-only — no free API tier; available via ChatGPT Plus/Pro. GPT-5.6 Terra: no — Free $5 credit for new accounts; paid thereafter.

Which is better for coding — GPT-5.6 Sol or GPT-5.6 Terra?

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