AI model comparison
GPT-5.6 Terra vs Claude Opus 4.8
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
OpenAI
GPT-5.6 Terra
GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier.
- Input / 1M
- $2
- Output / 1M
- $12
- Context
- 1.05M
Anthropic
Claude Opus 4.8
Claude Opus 4.8 is Anthropic's most capable generally available model in the Opus family.
- Input / 1M
- $5
- Output / 1M
- $25
- Context
- 1M
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
GPT-5.6 Terra
2.3x cheaper for a typical chat
Higher intelligence score
GPT-5.6 Terra
42.1 vs 41.8 on Artificial Analysis
Larger context window
GPT-5.6 Terra
1.05M vs 1M tokens
Newer release
GPT-5.6 Terra
Released July 9, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
GPT-5.6 Terra42.1Claude Opus 4.841.8Coding index
GPT-5.6 Terra76.7Claude Opus 4.874.3Agentic index
GPT-5.6 Terra43.2Claude Opus 4.841.9Pricing
GPT-5.6 Terra vs Claude Opus 4.8 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | GPT-5.6 Terra | Claude Opus 4.8 |
|---|---|---|
| Input tokensPer 1M tokens | $2 | $5 |
| Output tokensPer 1M tokens | $12 | $25 |
| Cached input (read)Per 1M tokens | $0.20 | $0.50 |
| Cache writePer 1M tokens | $2.50 | $6.25 |
| Long-context pricingPer 1M tokens, for very long prompts | $4 in / $18 out above 272K | Same rate at any length |
| Web searchPer request | $0.01 | $0.01 |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
GPT-5.6 Terra$10Claude Opus 4.8$22.50Coding task
30K in, 4K out
GPT-5.6 Terra$108$54 cachedClaude Opus 4.8$250$115 cachedLong document summary
150K in, 2K out
GPT-5.6 Terra$324$54 cachedClaude Opus 4.8$800$125 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | GPT-5.6 Terra | Claude Opus 4.8 |
|---|---|---|
| Context window | 1.05M tokens | 1M tokens |
| Max output | 128K tokens | 128K tokens |
| Input types | File, Image, Text | File, Image, Text |
| Output types | Text | Text |
| Reasoning effort levels | Max, Extra high, High, Medium, Low, None | Max, Extra high, High, Medium, Low |
| Default reasoning effort | Medium | High |
| Release date | July 9, 2026 | May 27, 2026 |
Features
Supported features
API features available for each model.
| Metric | GPT-5.6 Terra | Claude Opus 4.8 |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Supported |
| Temperature | Not supported | Not supported |
| Stop sequences | Not supported | Supported |
| Deterministic seed | Supported | Not supported |
| Verbosity control | Supported | Supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
GPT-5.6 TerraView full model details- GPT-5.6 Terra vs GPT-6 Sol
- GPT-5.6 Terra vs GPT-5.6 Sol
- GPT-5.6 Terra vs GLM 5.3
- GPT-5.6 Terra vs Grok 4.6
- GPT-5.6 Terra vs Kimi K3
- GPT-5.6 Terra vs Ling 3.1 Flash
- GPT-5.6 Terra vs Gemini 3.8 Flash
- GPT-5.6 Terra vs Claude Opus 4.7
- GPT-5.6 Terra vs Qwen3.8 2.4T A95B
- GPT-5.6 Terra vs DeepSeek V4.1 Flash
- GPT-5.6 Terra vs GPT-5.4
- GPT-5.6 Terra vs GPT-5.5
- GPT-5.6 Terra vs Claude Sonnet 5
Claude Opus 4.8View full model details- Claude Opus 4.8 vs Claude Fable 5.1
- Claude Opus 4.8 vs Claude Opus 5
- Claude Opus 4.8 vs Claude Fable 5
- Claude Opus 4.8 vs GLM 5.3
- Claude Opus 4.8 vs Kimi K3
- Claude Opus 4.8 vs Ling 3.1 Flash
- Claude Opus 4.8 vs Gemini 3.8 Flash
- Claude Opus 4.8 vs Claude Opus 4.7
- Claude Opus 4.8 vs DeepSeek V4.1 Flash
- Claude Opus 4.8 vs GPT-5.4
- Claude Opus 4.8 vs GPT-5.5
- Claude Opus 4.8 vs Claude Sonnet 5
- Claude Opus 4.8 vs Claude Opus 4.6
Our take
GPT-5.6 Terra is 2.3x cheaper for a typical chat. GPT-5.6 Terra scores higher on the Artificial Analysis Intelligence Index (42.1 vs 41.8). GPT-5.6 Terra has the larger context window (1.05M vs 1M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is GPT-5.6 Terra or Claude Opus 4.8 cheaper?
GPT-5.6 Terra is cheaper for a typical chat (2K input tokens and 500 output tokens). GPT-5.6 Terra costs $2 per 1M input tokens and $12 per 1M output tokens, while Claude Opus 4.8 costs $5 per 1M input tokens and $25 per 1M output tokens.
Which has a bigger context window, GPT-5.6 Terra or Claude Opus 4.8?
GPT-5.6 Terra supports up to 1.05M tokens of context, compared with 1M for Claude Opus 4.8.
Is GPT-5.6 Terra smarter than Claude Opus 4.8?
On the Artificial Analysis Intelligence Index, GPT-5.6 Terra scores 42.1 and Claude Opus 4.8 scores 41.8, putting GPT-5.6 Terra ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use GPT-5.6 Terra and Claude Opus 4.8 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see GPT-5.6 Terra and Claude Opus 4.8 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to GPT-5.6 Terra and Claude Opus 4.8 at the same time. Compare the answers side by side and keep the best one.