AI model comparison
GPT-6.1 Terra vs Claude Sonnet 5.5
Side by side comparison of GPT-6.1 Terra and Claude Sonnet 5.5 on pricing, benchmark scores, context window, and more.
GPT-6.1 Terra is the mid-tier model in OpenAI's GPT-6.1 series, priced below GPT-6.1 Sol.
- Input / 1M
- $1
- Output / 1M
- $5
- Context
- 1.05M
Claude Sonnet 5.5 is Anthropic's Sonnet-class model for well-scoped everyday work, succeeding Claude Sonnet 5 as a direct upgrade.
- Input / 1M
- $2
- Output / 1M
- $10
- Context
- 1M
Comparing image generators? Compare image models
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
GPT-6.1 Terra
2x cheaper for a typical chat
Higher intelligence score
Claude Sonnet 5.5
54.2 vs 51 on Artificial Analysis
Larger context window
GPT-6.1 Terra
1.05M vs 1M tokens
Newer release
GPT-6.1 Terra
Released October 26, 2026
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
GPT-6.1 Terra51Claude Sonnet 5.554.2Coding index
GPT-6.1 TerraNot availableClaude Sonnet 5.5Not availableAgentic index
GPT-6.1 TerraNot availableClaude Sonnet 5.5Not availablePricing
GPT-6.1 Terra vs Claude Sonnet 5.5 API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| Input tokensPer 1M tokens | $1 | $2 |
| Output tokensPer 1M tokens | $5 | $10 |
| Cached input (read)Per 1M tokens | $0.05 | $0.10 |
| Cache writePer 1M tokens | $1.25 | $2.50 |
| Long-context pricingPer 1M tokens, for very long prompts | $2 in / $7.50 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-6.1 Terra$4.50Claude Sonnet 5.5$9Coding task
30K in, 4K out
GPT-6.1 Terra$50$21.50 cachedClaude Sonnet 5.5$100$43 cachedLong document summary
150K in, 2K out
GPT-6.1 Terra$160$17.50 cachedClaude Sonnet 5.5$320$35 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| 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 | October 26, 2026 | September 28, 2026 |
Features
Supported features
API features available for each model.
| Metric | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| 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-6.1 TerraView full model details- GPT-6.1 Terra vs Claude Opus 5.5
- GPT-6.1 Terra vs GPT-6 Astra
- GPT-6.1 Terra vs GPT-6.1 Sol
- GPT-6.1 Terra vs Gemini 4 Argon
- GPT-6.1 Terra vs Claude Fable 5.1
- GPT-6.1 Terra vs Kimi K3.1 Pro
- GPT-6.1 Terra vs Muse Spark 1.3
- GPT-6.1 Terra vs Claude Haiku 5.5
- GPT-6.1 Terra vs GPT-6 Luna
- GPT-6.1 Terra vs DeepSeek V4.1 Flash 1017
- GPT-6.1 Terra vs DeepSeek V4.1 Flash
- GPT-6.1 Terra vs GLM 5.3 Flash
- GPT-6.1 Terra vs Hy4 preview
- GPT-6.1 Terra vs GLM 5.2
- GPT-6.1 Terra vs GPT-6 Sol
- GPT-6.1 Terra vs GPT-5.6 Terra
Claude Sonnet 5.5View full model details- Claude Sonnet 5.5 vs Claude Opus 5.5
- Claude Sonnet 5.5 vs GPT-6 Astra
- Claude Sonnet 5.5 vs GPT-6.1 Sol
- Claude Sonnet 5.5 vs Gemini 4 Argon
- Claude Sonnet 5.5 vs Claude Fable 5.1
- Claude Sonnet 5.5 vs Kimi K3.1 Pro
- Claude Sonnet 5.5 vs Muse Spark 1.3
- Claude Sonnet 5.5 vs Claude Haiku 5.5
- Claude Sonnet 5.5 vs DeepSeek V4.1 Flash 1017
- Claude Sonnet 5.5 vs DeepSeek V4.1 Flash
- Claude Sonnet 5.5 vs GLM 5.3 Flash
- Claude Sonnet 5.5 vs Hy4 preview
- Claude Sonnet 5.5 vs GPT-6 Luna
- Claude Sonnet 5.5 vs Kimi K3
- Claude Sonnet 5.5 vs GLM 5.2
- Claude Sonnet 5.5 vs Claude Sonnet 5
- Claude Sonnet 5.5 vs Claude Opus 5
- Claude Sonnet 5.5 vs GPT-5.6 Sol
- Claude Sonnet 5.5 vs GPT-6 Sol
- Claude Sonnet 5.5 vs Claude Sonnet 4.5
- Claude Sonnet 5.5 vs Claude Sonnet 4.6
- Claude Sonnet 5.5 vs GPT-5.6 Terra
- Claude Sonnet 5.5 vs Claude Opus 4.8
- Claude Sonnet 5.5 vs Claude Haiku 4.5
- Claude Sonnet 5.5 vs Grok 4.6
- Claude Sonnet 5.5 vs Muse Wonder
Our take
GPT-6.1 Terra is 2x cheaper for a typical chat. Claude Sonnet 5.5 scores higher on the Artificial Analysis Intelligence Index (54.2 vs 51). GPT-6.1 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-6.1 Terra or Claude Sonnet 5.5 cheaper?
GPT-6.1 Terra is cheaper for a typical chat (2K input tokens and 500 output tokens). GPT-6.1 Terra costs $1 per 1M input tokens and $5 per 1M output tokens, while Claude Sonnet 5.5 costs $2 per 1M input tokens and $10 per 1M output tokens.
Which has a bigger context window, GPT-6.1 Terra or Claude Sonnet 5.5?
GPT-6.1 Terra supports up to 1.05M tokens of context, compared with 1M for Claude Sonnet 5.5.
Is GPT-6.1 Terra smarter than Claude Sonnet 5.5?
On the Artificial Analysis Intelligence Index, GPT-6.1 Terra scores 51 and Claude Sonnet 5.5 scores 54.2, putting Claude Sonnet 5.5 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use GPT-6.1 Terra and Claude Sonnet 5.5 at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see GPT-6.1 Terra and Claude Sonnet 5.5 answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to GPT-6.1 Terra and Claude Sonnet 5.5 at the same time. Compare the answers side by side and keep the best one.