High-volume, cost-sensitive work
Choose Gemini 4 Argon
Gemini 4 Argon costs 11% less on a typical mix of three input tokens for every output token ($4.00 against $4.50 per million tokens).
Gemini 4 Argon vs GPT-5.6 Terra: price, context and capabilities
Choose Gemini 4 Argon for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), the hardest reasoning tasks and the latest release. Choose GPT-5.6 Terra for reasoning over long documents.
In short
- Gemini 4 Argon is 11% cheaper than GPT-5.6 Terra at the headline price ($4.00 / 1M tokens vs $4.50 / 1M tokens).
- GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M.
- Gemini 4 Argon is the newer model (October 2026, against Jul 9, 2026).
Which should you choose?
Each answer below comes straight from the published prices, specifications and independent benchmark results.
Writing and code generation
Choose Gemini 4 Argon
Gemini 4 Argon charges $10.00 per million output tokens, against $12.00 for GPT-5.6 Terra. Output dominates the bill when answers are long.
Reused prompts and documents (RAG, agents)
Choose Gemini 4 Argon
Gemini 4 Argon charges $0.10 per million cached input tokens, against $0.20 for GPT-5.6 Terra.
Hardest reasoning tasks
Choose Gemini 4 Argon
Gemini 4 Argon scores 52.6 on the Artificial Analysis Intelligence Index, against 42.1 for GPT-5.6 Terra.
Reasoning over long documents
Choose GPT-5.6 Terra
GPT-5.6 Terra scores 83% on Long-context reasoning (AA-LCR), against 79.7% for Gemini 4 Argon.
Latest release
Choose Gemini 4 Argon
Gemini 4 Argon is the newer release (October 2026, against Jul 9, 2026 for GPT-5.6 Terra).
Monthly cost at three volumes
| Volume | Gemini 4 Argon | GPT-5.6 Terra | Difference |
|---|---|---|---|
| Prototype: 1M input, 250K output tokens | $4.50 | $5.00 | Gemini 4 Argon, $0.50 less |
| Production: 20M input, 5M output tokens | $90.00 | $100.00 | Gemini 4 Argon, $10.00 less |
| Scale: 500M input, 100M output tokens | $2,000 | $2,200 | Gemini 4 Argon, $200.00 less |
Standard rates, without caching or batch discounts. Volumes are per month.
Specifications side by side
| Gemini 4 Argon | GPT-5.6 Terra | |
|---|---|---|
| Provider | OpenAI | |
| Category | Language models | Language models |
| Status | Generally available | Generally available |
| Headline price | $4.00 / 1M tokens | $4.50 / 1M tokens |
| Input | $2.00 / 1M tokens | $2.00 / 1M tokens |
| Output | $10.00 / 1M tokens | $12.00 / 1M tokens |
| Cached input | $0.10 / 1M tokens | $0.20 / 1M tokens |
| Context window | 1.05M | 1.05M |
| Max output | 66k | 128k |
| Released | October 2026 | Jul 9, 2026 |
| Knowledge cutoff | No data | February 2026 |
| Licence | Proprietary | Proprietary |
| Capabilities | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API | Vision, Reasoning, Tool calling, Structured output, Prompt caching, Batch API |
| API model id | gemini-4-argon | gpt-5.6-terra |
Benchmarks side by side
Leader in bold.
| Benchmark | Gemini 4 Argon | GPT-5.6 Terra |
|---|---|---|
| Intelligence Index | 52.6 | 42.1 |
| SciCode | 61.8% | 55% |
| Humanity's Last Exam | 57.1% | 42.9% |
| Long-context reasoning (AA-LCR) | 79.7% | 83% |
| Terminal-Bench Hard | No data | 57.6% |
| GPQA Diamond | No data | 92.5% |
| IFBench (instruction following) | No data | 71.2% |
| τ²-Bench (agentic tool use) | No data | 86.3% |
| MMMU-Pro (visual reasoning) | No data | 80.7% |
Independent evaluations by Artificial Analysis, run the same way for every model, at the reasoning setting shown. Percentages unless marked as an index.
Frequently asked questions
Should I choose Gemini 4 Argon or GPT-5.6 Terra?
Choose Gemini 4 Argon for high-volume, cost-sensitive work, writing and code generation, reused prompts and documents (RAG, agents), the hardest reasoning tasks and the latest release. Choose GPT-5.6 Terra for reasoning over long documents.
Which is cheaper, Gemini 4 Argon or GPT-5.6 Terra?
Gemini 4 Argon is 11% cheaper than GPT-5.6 Terra at the headline price ($4.00 / 1M tokens vs $4.50 / 1M tokens).
Which has the larger context window, Gemini 4 Argon or GPT-5.6 Terra?
GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M.
What is the difference between Gemini 4 Argon and GPT-5.6 Terra?
Gemini 4 Argon is made by Google and GPT-5.6 Terra by OpenAI. Gemini 4 Argon is 11% cheaper than GPT-5.6 Terra at the headline price ($4.00 / 1M tokens vs $4.50 / 1M tokens). GPT-5.6 Terra reads more per request: 1.05M tokens against 1.05M. Gemini 4 Argon is the newer model (October 2026, against Jul 9, 2026).
How much do Gemini 4 Argon and GPT-5.6 Terra cost per month?
At 20 million input and 5 million output tokens a month, Gemini 4 Argon costs $90.00 and GPT-5.6 Terra costs $100.00, at standard rates.
Which is newer, Gemini 4 Argon or GPT-5.6 Terra?
Gemini 4 Argon was released on October 2026 and GPT-5.6 Terra on Jul 9, 2026.