text model comparison
Claude Sonnet 5.5 vs GPT-6.1 Terra
Claude Sonnet 5.5 and GPT-6.1 Terra are both current text models, from Anthropic and OpenAI. GPT-6.1 Terra is 50% cheaper per 1M input tokens than Claude Sonnet 5.5, $1 vs $2. On Arena WebDev, Claude Sonnet 5.5 scores 1770 Elo and GPT-6.1 Terra 1673 Elo (Arena, measured October 28, 2026). GPT-6.1 Terra has the larger context window, 1,050,000 vs 1,000,000 tokens.
- Higher Arena WebDev
- Claude Sonnet 5.51770 Elo against 1673 Elo
- Lower price per 1M input tokens
- GPT-6.1 Terra$1 against $2
- Longer context window
- GPT-6.1 Terra1.05M tokens against 1M tokens
- Newer release
- GPT-6.1 TerraOct 2026 against Sep 2026
Data verified November 3, 2026 · Dataset 2026-11-03
Side by side
Claude Sonnet 5.5 and GPT-6.1 Terra, line by line
Prices in effect today, compared at the same tier wherever both list one. The better value in each row is highlighted.
| Fact | Claude Sonnet 5.5 | GPT-6.1 Terra |
|---|---|---|
| Price | ||
| Price per 1M input tokens | $2 | $1 (better) |
| Price per 1M output tokens | $10 | $5 (better) |
| Independent benchmarks | ||
| Arena WebDev | 1770 Elo (#3 of 45) (better) | 1673 Elo (#10 of 45) |
| FrontierMath Tiers 1-3 (v2) | 88.8% (#8 of 42) | 90.9% (#4 of 42) (better) |
| GPQA Diamond | 95.6% (#3 of 41) (better) | 94.3% (#7 of 41) |
| SimpleQA Verified | 46.5% (#23 of 38) | 57.3% (#15 of 38) (better) |
| Arena Text | 1477 Elo (#19 of 51) | Not measured |
| Specs | ||
| Provider | Anthropic | OpenAI |
| Release date | September 28, 2026 | October 26, 2026 |
| Access | API only | API only |
| Context window | 1,000,000 tokens | 1,050,000 tokens |
| Max output | 128,000 tokens | 128,000 tokens |
| Input | text, image | text, image |
| Output | text | text |
Charts
Against every current text model
Where Claude Sonnet 5.5 and GPT-6.1 Terra land among the current models of their task, on every independent benchmark, on price and on context.
Where each stands
On Arena WebDev, Claude Sonnet 5.5 ranks #3 and GPT-6.1 Terra #10 of 45 current models. Each bar is the share of current models it beats: on score, price and context.
Independent benchmarks
Arena Text
Claude Sonnet 5.5:#19of 51
1,477 Elo · ahead of 62%
GPT-6.1 Terra: Not scored
Arena WebDev
Claude Sonnet 5.5:#3of 45
1,770 Elo · ahead of 95%
GPT-6.1 Terra:#10of 45
1,673 Elo · ahead of 80%
FrontierMath Tiers 1-3 (v2)
Claude Sonnet 5.5:#8of 42
88.8% · ahead of 83%
GPT-6.1 Terra:#4of 42
90.9% · ahead of 93%
GPQA Diamond
Claude Sonnet 5.5:#3of 41
95.6% · ahead of 95%
GPT-6.1 Terra:#7of 41
94.3% · ahead of 83%
SimpleQA Verified
Claude Sonnet 5.5:#23of 38
46.5% · ahead of 41%
GPT-6.1 Terra:#15of 38
57.3% · ahead of 62%
Price and context
Price per 1M input tokens
Claude Sonnet 5.5:#29of 52
$2 · cheaper than 24%
GPT-6.1 Terra:#21of 52
$1 · cheaper than 59%
Price per 1M output tokens
Claude Sonnet 5.5:#34of 52
$10 · cheaper than 25%
GPT-6.1 Terra:#27of 52
$5 · cheaper than 49%
Context window
Claude Sonnet 5.5:#26of 64
1M tokens · longer than 22%
GPT-6.1 Terra:#1of 64
1.05M tokens · longer than 86%
Quality against price
Claude Sonnet 5.5 scores 1,477 at $4 (blended price per 1M tokens). The line joins the current models no other beats on both price and Arena Text score; hover any point to name it.
Quality against price: the data
| Model | Provider | Blended price per 1M tokens | Arena Text (Elo) |
|---|---|---|---|
| Gemini 4 Argon | $4 | 1,520 | |
| Claude Opus 5.5 | Anthropic | $8 | 1,509 |
| Muse Wonder | Meta | $8 | 1,507 |
| Claude Fable 5 | Anthropic | $20 | 1,504 |
| Claude Fable 5.1 | Anthropic | $20 | 1,504 |
| Gemini 3.8 Flash | $1.50 | 1,496 | |
| Muse Spark 1.3 | Meta | $2 | 1,495 |
| Claude Opus 5 | Anthropic | $10 | 1,492 |
| Kimi K3 | Moonshot Kimi | $6 | 1,488 |
| GPT-5.6 Sol | OpenAI | $8 | 1,485 |
| Gemini 3.6 Flash | $3 | 1,483 | |
| GPT-5.5 | OpenAI | $11 | 1,482 |
| Claude Opus 4.8 | Anthropic | $10 | 1,482 |
| Qwen3.8-Max | Alibaba Qwen | $3 | 1,482 |
| GPT-6.1 Sol | OpenAI | $4 | 1,481 |
| GLM-5.3 | Z.ai | $2.15 | 1,481 |
| MiMo-V2.6-Pro | Xiaomi MiMo | $0.54 | 1,480 |
| Claude Sonnet 5.5 | Anthropic | $4 | 1,477 |
| GLM-5.3-Flash | Z.ai | $0.24 | 1,477 |
| GPT-6 Astra | OpenAI | $20 | 1,476 |
| DeepSeek-V4.1-Flash | DeepSeek | $0.52 | 1,476 |
| GPT-5.4 | OpenAI | $5.63 | 1,475 |
| Gemini 3 Flash Preview | $1.13 | 1,473 | |
| Grok 4.20 | xAI | $1.56 | 1,472 |
| GPT-5.6 Terra | OpenAI | $4.50 | 1,467 |
| Grok 4.5 | xAI | $3 | 1,465 |
| DeepSeek-V4-Pro | DeepSeek | $1.98 | 1,465 |
| Claude Sonnet 5 | Anthropic | $4 | 1,462 |
| GPT-6 Sol | OpenAI | $4 | 1,458 |
| Gemini 3.5 Flash-Lite | $0.85 | 1,456 | |
| Grok 4.6 | xAI | $3 | 1,455 |
| GPT-5.6 Luna | OpenAI | $0.45 | 1,453 |
| MiMo-V2.6-Flash | Xiaomi MiMo | $0.18 | 1,448 |
| Step 5 Preview | StepFun | $1.43 | 1,448 |
| Grok 4.3 | xAI | $1.56 | 1,442 |
| GPT-6 Luna | OpenAI | $0.20 | 1,441 |
| Grok 4.7 | xAI | $3 | 1,441 |
| Mistral Large 4 | Mistral AI | $1.05 | 1,432 |
| Claude Haiku 5.5 | Anthropic | $0.20 | 1,425 |
| GPT-4.1 | OpenAI | $3.50 | 1,415 |
| Solar Pro 4 | Upstage | $0.52 | 1,388 |
| GPT-4.1 mini | OpenAI | $0.70 | 1,383 |
| GPT-4.1 nano | OpenAI | $0.18 | 1,322 |
Cost
What each costs
Example workloads at each provider's listed rates, then every other rate either one lists. The cheaper figure in each row is highlighted.
The same work, priced
For 10M input and 2M output tokens, Claude Sonnet 5.5 costs 2.0 times as much as GPT-6.1 Terra, at each provider's listed rates.
10M input and 2M output tokens
Claude Sonnet 5.5 costs 2.0× as much
- Claude Sonnet 5.5
- $40
- GPT-6.1 Terra
- $20
The same, with 9M of the input tokens cached
Claude Sonnet 5.5 costs 2.0× as much
- Claude Sonnet 5.5
- $22.90
- GPT-6.1 Terra
- $11.45
| Workload or rate | Claude Sonnet 5.5 | GPT-6.1 Terra |
|---|---|---|
| Example workloads | ||
| 10M input and 2M output tokens | $40 | $20 (better) |
| The same, with 9M of the input tokens cached | $22.90 | $11.45 (better) |
| The same, through the batch API | $20 | Not listed |
| Other listed rates | ||
| 1M input tokens, cached | $0.10 | $0.05 (better) |
| 1M input tokens, 5-minute cache write | $2.50 | Not listed |
| 1M input tokens, 1-hour cache write | $4 | Not listed |
| 1M input tokens, batch | $1 | Not listed |
| 1M output tokens, batch | $5 | Not listed |
| 1M input tokens, prompts over 272K tokens | Not listed | $2 |
| 1M output tokens, prompts over 272K tokens | Not listed | $7.50 |
Your own bill will differ. These figures use list prices and example workloads. The AI Model Cost Audit reviews your real usage, shortlists models that score as well for each task for less, and estimates the savings.
Launch price $100, regular price $150
Verdict
When to choose each
Claude Sonnet 5.5
Where it leads
- Higher Arena WebDev score, 1770 Elo vs 1673 Elo
- Higher GPQA Diamond score, 95.6% vs 94.3%
- Batch pricing, $1 input and $5 output per 1M tokens
Best for
- Production workloads that need frontier-adjacent quality at a mid-tier rate
- Latency-sensitive agent steps inside a larger pipeline
Watch out for
- Same list price as Claude Sonnet 5, so the gain is capability and cache economics rather than a cheaper rate card
- Anthropic positions Opus 5.5 rather than this as the default, so reach for Sonnet 5.5 when latency matters more than peak capability
GPT-6.1 Terra
Where it leads
- Lower input and output prices, $1 and $5 vs $2 and $10 per 1M tokens
- Higher FrontierMath Tiers 1-3 (v2) score, 90.9% vs 88.8%
- Higher SimpleQA Verified score, 57.3% vs 46.5%
- Larger context window 1,050,000 vs 1,000,000 tokens
- Cheaper cached input, $0.05 vs $0.10 per 1M tokens
Best for
- Computer-use and tool-calling agents at half GPT-6.1 Sol's price
- High-volume reasoning work that stays under the 272K long-context threshold
Watch out for
- Prompts over 272,000 input tokens bill the whole request at $2 input and $7.50 output per 1M tokens
- Reads text and images only: audio and video input are not supported
From benchmark to production
Building on Claude Sonnet 5.5 or GPT-6.1 Terra?
Public scores rarely hold on your own data. We test both models on your real tasks, then build the agent or pipeline around the one that wins.
AI Model Cost AuditLaunch price $100, regular price $150What the audit includes
FAQ
Claude Sonnet 5.5 vs GPT-6.1 Terra FAQ
Which is cheaper, Claude Sonnet 5.5 or GPT-6.1 Terra?
GPT-6.1 Terra is 50% cheaper per 1M input tokens than Claude Sonnet 5.5, $1 vs $2. For 10M input and 2M output tokens, Claude Sonnet 5.5 costs $40 and GPT-6.1 Terra $20 at standard rates.
Which is cheaper with prompt caching, Claude Sonnet 5.5 or GPT-6.1 Terra?
Claude Sonnet 5.5 charges $0.10 per 1M cached input tokens, 95% below its standard input rate, and GPT-6.1 Terra $0.05, 95% below. With 9M of 10M input tokens cached and 2M output tokens, Claude Sonnet 5.5 costs $22.90 and GPT-6.1 Terra $11.45.
Which scores higher on independent benchmarks, Claude Sonnet 5.5 or GPT-6.1 Terra?
Claude Sonnet 5.5 leads on Arena WebDev, 1770 Elo to 1673 Elo; GPT-6.1 Terra leads on FrontierMath Tiers 1-3 (v2), 90.9% to 88.8%; Claude Sonnet 5.5 leads on GPQA Diamond, 95.6% to 94.3%. Scores are independent evaluations, not either vendor's launch figures.
Which has the larger context window, Claude Sonnet 5.5 or GPT-6.1 Terra?
GPT-6.1 Terra has the larger context window, 1,050,000 vs 1,000,000 tokens. Both return up to 128,000 tokens per response.
Further reading
More on Claude Sonnet 5.5 and GPT-6.1 Terra
Articles on Claude Sonnet 5.5 and GPT-6.1 Terra
- GPT-6.1 Terra: Price, Benchmarks and When to Use ItOctober 27, 2026
- Claude Sonnet 5.5 vs GPT-6 Luna: Cost, Speed and AccuracySeptember 29, 2026
- Claude Sonnet 5.5: Benchmarks, Price and When to Use OpusSeptember 29, 2026
Related comparisons
- Claude Haiku 5.5 vs Claude Sonnet 5.5
- Claude Haiku 5.5 vs GPT-6.1 Terra
- Claude Sonnet 5.5 vs Mistral Large 4
- Claude Sonnet 5 vs GPT-6.1 Terra
- Claude Sonnet 5.5 vs Gemini 4 Argon
- DeepSeek-V4.1-Flash vs GPT-6.1 Terra
- Claude Sonnet 5.5 vs GPT-6.1 Sol
- Gemini 3.8 Flash vs GPT-6.1 Terra
- Claude Opus 4.8 vs Claude Sonnet 5.5
- GPT-6.1 Sol vs GPT-6.1 Terra
- Claude Opus 5.5 vs Claude Sonnet 5.5
- GPT-6.1 Terra vs GPT-6 Astra
Production evaluation
Choosing between Claude Sonnet 5.5 and GPT-6.1 Terra?
Public benchmarks narrow the shortlist. We run both on your own tasks, data and cost limits, then build the routing and review controls to run the winner in production.
- A head-to-head evaluation on your real workload
- Routing between models by cost and difficulty
