By the toolist.ai editors. Researched from public sources, not hands-on tested by toolist.ai. Updated October 27, 2026; prices checked October 21, 2026.
GPT-6.1 Terra vs Claude Sonnet 5.5
Verdict
Pick Claude Sonnet 5.5 for harder work and GPT-6.1 Terra for high-volume work where price comes first. Terra costs half as much per token ($1 and $5 per million against $2 and $10) and half as much for cached input ($0.05 against $0.10). Sonnet 5.5 scores higher on the Artificial Analysis Intelligence Index, 54 against 51 at max effort and 41 against 38 at each model's default effort, and it is faster, at 115.1 output tokens a second against 91.0 at each model's default effort.
Verdict based on published prices, limits and benchmarks, not on our own tests.
Choose GPT-6.1 Terra if
- Cost matters most: Terra's $1 and $5 per million tokens against Sonnet's $2 and $10
- You send product photos, technical drawings or application screens, which OpenAI says Terra is built for
- You reuse long prompts: cached input costs $0.05 per million tokens against $0.10
Choose Claude Sonnet 5.5 if
- You want the higher score at max effort: 54 against 51 on the Intelligence Index
- You want faster answers: 115.1 against 91.0 output tokens a second at each model's default effort
- You use the Claude apps, since Sonnet models are in them on every plan from Free to Enterprise
Price
Input costs 2 times as much on Claude Sonnet 5.5 as on GPT-6.1 Terra. Output costs 2 times as much on Claude Sonnet 5.5 as on GPT-6.1 Terra.
| Per million tokens | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| Input | $1 source | $2 source |
| Cached input | $0.05 source | $0.10 source |
| Output | $5 source | $10 source |
GPT-6.1 Terra: Prompts over 272,000 input tokens cost twice the input and cache rates and 1.5 times the output rate for the whole request. Batch and Flex cost half; Fast mode costs double. Cache writes cost $1.25 per million tokens with 30-minute retention and $2.50 with 12-hour retention.
Claude Sonnet 5.5: Cache writes cost $2.50 per million tokens (5-minute cache) or $4 (1-hour cache). The Batch API costs half. There is no long-context surcharge and no fast mode.
Worked example: what a month costs
We priced three monthly workloads at the standard rates. The provider does not publish these figures.
| Workload | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| Support chatbot 100,000 replies, each 3,000 input and 400 output tokens, no caching (300M in, 40M out) | $500 | $1,000 |
| Document Q&A 5,000 questions over the same 60,000-token document set (90% cache hits), 800 output tokens each (300M in, 4M out) | $63.50 | $127 |
| Coding agent 200 tasks, each 1.5 million input tokens (90% cache hits) and 50,000 output tokens (300M in, 10M out) | $93.50 | $187 |
Price your own workload
| Model | Cost a month |
|---|---|
| GPT-6.1 Terra | $75.00 |
| Claude Sonnet 5.5 | $150 |
Standard API prices, no batch or priority discounts. Cached input is billed at the cache-read price; cache-write charges are not included. Reasoning models bill their thinking as output tokens.
Limits and release dates
| GPT-6.1 Terra | Claude Sonnet 5.5 | |
|---|---|---|
| Released | October 26, 2026 source | September 28, 2026 source |
| Context window | 1,050,000 tokens source | 1,000,000 tokens source |
| Maximum output | 128,000 tokens source | 128,000 tokens source |
| Knowledge cutoff | June 1, 2026 source | June 2026 source |
| Input and output | Text and images in; text out source | Text and images in; text out source |
| API model name | gpt-6.1-terra | claude-sonnet-5-5 |
Benchmarks
Scores as published by the provider or measured by Artificial Analysis; higher is better. A dash means no score was published.
| Benchmark | GPT-6.1 Terra | Claude Sonnet 5.5 |
|---|---|---|
| Artificial Analysis Intelligence Index max effort | 51.0 source | 54.0 source |
| Intelligence Index at everyday effort | 38.0 (medium effort, the API default) source | 41.0 (high effort, the API default) source |
| Terminal-Bench 4.0 | – | 64.0% (max effort) source |
| HLE-Diamond | – | 53.0% (max effort) source |
| Terminal-Bench-Science 0.1 | – | 53.0% (max effort) source |
| Output speed | 91 tokens/s (medium effort, Artificial Analysis) source | 115.1 tokens/s (high effort, Artificial Analysis) source |
Benchmark and speed data from Artificial Analysis where linked.
Read more
- GPT-6.1 Terra: price, context window and benchmarks
- Claude Sonnet 5.5: price, context window and benchmarks
- Claude Haiku 5.5 vs Claude Sonnet 5.5
- Claude Opus 5.5 vs Claude Sonnet 5.5
- GPT-6.1 Sol vs Claude Sonnet 5.5
- GPT-6.1 Terra vs GPT-6.1 Sol
- GPT-6.1 Terra vs GPT-6 Astra
- AI model API price table
Sources
- OpenAI API docs: GPT-6.1 Terra (checked 2026-10-27)
- OpenAI API docs: Pricing (checked 2026-10-27)
- OpenAI API docs: Changelog (checked 2026-10-27)
- Artificial Analysis: GPT-6.1 Terra (max) (checked 2026-10-27)
- Artificial Analysis: GPT-6.1 Terra (medium) (checked 2026-10-27)
- OpenRouter: GPT-6.1 Terra (checked 2026-10-27)
- Anthropic: Introducing Claude Sonnet 5.5 (checked 2026-10-21)
- Claude docs: Claude Sonnet 5.5 (checked 2026-10-21)
- Claude docs: What's new in Claude Sonnet 5.5 (checked 2026-10-21)
- Claude docs: Pricing (checked 2026-10-21)
- Claude plans and pricing (checked 2026-10-21)
- Claude docs: API and data retention (checked 2026-10-21)
- Artificial Analysis: Claude Sonnet 5.5 (max) (checked 2026-10-27)
- Artificial Analysis: Claude Sonnet 5.5 (high) (checked 2026-10-27)
- Artificial Analysis: GPT-6.1 Sol vs Claude Sonnet 5.5 (checked 2026-10-27)
- OpenRouter: Claude Sonnet 5.5 (checked 2026-10-21)