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- Claude Opus 5.5 vs. GPT-5.6 Terra
AnthropicOpenAILLM matchup
Claude Opus 5.5vs.GPT-5.6 Terra
Which one is better?
Claude Opus 5.5 performs better than GPT-5.6 Terra, but costs 2 times (input) and 1.7 times (output) as much.
Claude Opus 5.5
Rank 1
GPT-5.6 Terra
Rank 26
Claude Opus 5.5
GPT-5.6 Terra
Claude Opus 5.5
GPT-5.6 Terra
Claude Opus 5.5
Rank 8 of 785
GPT-5.6 Terra
Rank 19 of 785
Above 272,000 tokens of context, GPT-5.6 Terra costs more: $4 input and $18 output per 1M tokens.
Choose Claude Opus 5.5 for
Choose GPT-5.6 Terra for
No clear advantage
On this page
Where is the difference?
Strengths at a glance
Opus 5.5GPT-5.6 TerraMedian of all ranked models
95 % range: Opus 5.5 121.2 to 138.7, GPT-5.6 Terra 98.6 to 109.3.
The same values and verdicts as the bars below. In the close-up the net starts at 85 points, just below the weaker model's lowest value; the reference group average is 100.
Opus 5.5 is ahead in 10 of 10 areas, GPT-5.6 Terra in none.
Opus 5.5 ahead: 10
Bar length shows the gap in index points (full width 15 points, one standard deviation of the reference group). Solid means clearly ahead, hatched not certain yet, a thin grey bar level.
Show 4 more areas that do not count toward the overall index
Bar length shows the gap in index points (full width 15 points, one standard deviation of the reference group). Solid means clearly ahead, hatched not certain yet, a thin grey bar level.
Claude Opus 5.5 vs. GPT-5.6 Terra at the same effort
Both models measured at the same reasoning efforts. This shows whether a lead comes from the model or only from more compute.
| Effort | Opus 5.5 | GPT-5.6 Terra | Gap | Verdict | Test series |
|---|---|---|---|---|---|
| max | 126.1 | 100.7 | 23.9 | Opus 5.5 ahead | 12 |
| Overall index (max vs. max) | 126.1 | 100.7 | 25.4 | Opus 5.5 ahead |
Gap and verdict compare only the Artificial Analysis test series in which both models are measured at that effort. Tied below 3 points, ahead only beyond two standard errors. The single values rest on all test series of each model, so their difference can deviate from the gap.
Which model for which task?
Everyday tasks, translated from the area values above. Each row names the values it rests on.
See for yourself: same task, one attempt
The same prompt for both models. We show the latest attempt without fixes; it does not count toward the overall index.
Claude Opus 5.5

Oct 1, 2026 · 33 s · $0.07
Test details
- Run date
- Oct 1, 2026
- API provider
- openrouter
- Requested API model
- anthropic/claude-opus-5.5
- Reasoning setting
- high
- Token limit including reasoning
- 8,192 tokens
- Output tokens
- 3,536 tokens
- Cost of the attempt
- $0.0708
- Response time
- 33.2 s
- API model reported in response
- anthropic/claude-opus-5.5
- Pinned endpoint
- Anthropic | anthropic/claude-opus-5.5-20260921
- Temperature
- Provider default
- Test protocol
- community-visual-tests-v1
- Technical checks
- Passed, not a quality rating
Visually reviewed. This individual test does not establish overall model quality.
GPT-5.6 Terra

Sep 7, 2026 · 65 s · $0.04
Test details
- Run date
- Sep 7, 2026
- API provider
- openrouter
- Requested API model
- openai/gpt-5.6-terra
- Reasoning setting
- high
- Token limit including reasoning
- 8,192 tokens
- Output tokens
- 3,373 tokens
- Cost of the attempt
- $0.0405
- Response time
- 64.6 s
- API model reported in response
- openai/gpt-5.6-terra
- Pinned endpoint
- OpenAI | openai/gpt-5.6-terra-20260709
- Temperature
- Provider default
- Test protocol
- community-visual-tests-v1
- Technical checks
- Passed, not a quality rating
Visually reviewed. This individual test does not establish overall model quality.
SVG short test
SVG short test
One SVG task with the same fixed settings for every model, without hidden thinking.
Prompt
Return only one standalone SVG of a pelican riding a bicycle. Use viewBox="0 0 800 600", simple shapes, two clearly visible wheels and a recognizable pelican with a long beak. At most 30 SVG elements and 1800 characters. No Markdown, explanations, comments, scripts, animation, CSS or external resources.
Claude Opus 5.5
Unavailable in this round
GPT-5.6 Terra
Unavailable in this round
Claude Opus 5.5 and GPT-5.6 Terra in the overall index
Every model with a place in the overall index, both models of this matchup highlighted. You can add or hide other models.
Overall index (Gradually Meta-Score v4)
20 of 92 models
4 models in this view are measured at a lower reasoning effort than max in the overall index. Dashed column: lower reasoning effort than the top.
Popularity compared
How often the models are searched for, used and mentioned, on a scale from 0 to 100.
Both are about as popular: Claude Opus 5.5 68, GPT-5.6 Terra 64 out of 100.
Over time
Weekly values from October 18, 2026 to November 7, 2026
Claude Opus 5.5GPT-5.6 Terra
All data side by side
The better value is bold. For the overall index only when the gap is clear.
| Metric | Claude Opus 5.5 | GPT-5.6 Terra |
|---|---|---|
| Intelligence | ||
| Overall indexpoints, 100 = reference group average, higher is better | 126.1 | 100.7 |
| Rank | Rank 1 of 92 | Rank 26 of 92 |
| Price per 1M tokens | ||
| Inputwhat you send | $4 | $2above 272,000 tokens: $4 |
| Outputwhat the model writes | $20 | $12above 272,000 tokens: $18 |
| Cost per task (own tests)average of 3 original-protocol tasks both models passed (SVG short test not included) | $0.11 | $0.047 |
| Speed | ||
| Tokens per second | 106 | 100 |
| Popularity | ||
| Popularitysearch, usage and mentions, 0 to 100 | 68Rank 8 of 785 | 64Rank 19 of 785 |
| Technical | ||
| Context windowhow much text the model reads at once | 1 M tokens≈ 1,500 A4 pages | 1.05 M tokens≈ 1,580 A4 pages |
| Knowledge cutoff | June 2026 | Feb 16, 2026 |
| Released | Sep 22, 2026 | Jul 9, 2026 |
| Availability | Active | Active |
| Open weights | no | no |
Prices without caching or batch discounts · Page count as a rule of thumb from Artificial Analysis
Is there a better choice?
Overall index 105.3, rank 19$1 input and $5 output per 1M tokens
Opus 5.5 vs. GPT-6.1 TerraOverall index 122.8, rank 4$2 input and $10 output per 1M tokens
Opus 5.5 vs. Claude Sonnet 5.5Shared benchmarks
Single results from the same benchmark version, task and metric. A value is bold only with the same test setup and a clear gap.
A: Claude Opus 5.5B: GPT-5.6 Terra
Show 54 more benchmarks
More comparisons
Compare Claude Opus 5.5 and GPT-5.6 Terra with the models people compare them with most often.
Compare another matchup
Predecessor and successor
The most popular comparisons
- 1Claude Opus 5.5 vs. GPT-6 Astra
- 2GPT-6 Luna vs. GPT-5.6 Terra
- 3Claude Opus 5.5 vs. Claude Sonnet 5.5
- 4Claude Opus 5.5 vs. DeepSeek-V4-Pro
- 5Claude Opus 5.5 vs. Kimi K3.1 Pro
- 6Claude Opus 5.5 vs. Gemini 4 Argon
- 7Claude Opus 5.5 vs. Gemini 3.8 Flash
- 8Claude Opus 5.5 vs. Claude Fable 5.1
- 9Claude Opus 5.5 vs. DeepSeek-V4.1-Flash
Show all 58 comparisons
- 10Claude Opus 5.5 vs. Qwen 3.8 Max 0902
- 11Claude Opus 5.5 vs. GLM-5.3-Flash
- 12Claude Opus 5.5 vs. GPT-6.1 Sol
- 13Claude Opus 5.5 vs. Kimi K3
- 14Claude Opus 5.5 vs. Claude Sonnet 5
- 15Claude Opus 5.5 vs. Claude Haiku 5.5
- 16GPT-6.1 Sol vs. GPT-5.6 Terra
- 17Claude Opus 5.5 vs. GLM-5.3
- 18Claude Opus 5.5 vs. Gemini 3.1 Pro Preview
- 19Claude Sonnet 5.5 vs. GPT-5.6 Terra
- 20Claude Opus 5.5 vs. Claude Opus 4.6
- 21GPT-6 Sol vs. GPT-5.6 Terra
- 22Claude Opus 5.5 vs. Claude Sonnet 4.6
- 23Claude Opus 5.5 vs. Qwen 3.8 27B
- 24GPT-6 Astra vs. GPT-5.6 Terra
- 25Claude Opus 5.5 vs. Grok 4.6
- 26GPT-5.6 Terra vs. DeepSeek-V4.1-Flash
- 27Claude Opus 5.5 vs. GLM-5.2
- 28Claude Opus 5.5 vs. Gemini 4 Carbon
- 29Claude Opus 5.5 vs. DeepSeek V4.1 Flash 1017
- 30Claude Opus 5.5 vs. Claude Sonnet 4.5
- 31Claude Opus 5.5 vs. Muse Spark 1.3
- 32Claude Opus 5.5 vs. Claude Opus 4.8
- 33Claude Opus 5.5 vs. GPT-5.6 Luna
- 34Claude Opus 5.5 vs. Mistral Large 4
- 35Claude Opus 5.5 vs. GPT-5.6 Sol
- 36Claude Opus 5.5 vs. GPT-5.5
- 37Claude Opus 5.5 vs. DeepSeek-V4-Flash
- 38Claude Opus 5.5 vs. Grok 4.7
- 39Claude Opus 5.5 vs. Mistral Large 3
- 40Claude Opus 5.5 vs. GPT-6 Luna
- 41Claude Opus 5.5 vs. Claude Opus 4.5
- 42GPT-5.6 Terra vs. Grok 4.7
- 43Claude Opus 5.5 vs. Claude Fable 5
- 44Claude Opus 5.5 vs. GPT-6 Sol
- 45Claude Opus 5 vs. GPT-5.6 Terra
- 46Claude Opus 5.5 vs. Gemini 3.6 Flash
- 47Claude Opus 5.5 vs. Mistral Medium 3.5
- 48Claude Opus 5.5 vs. Muse Wonder Full
- 49Claude Opus 5.5 vs. Claude Haiku 4.5
- 50Claude Sonnet 4.6 vs. GPT-5.6 Terra
- 51GPT-5.6 Terra vs. Gemini 3.7 Flash
- 52Claude Opus 5.5 vs. Gemini 3.5 Flash
- 53Claude Opus 5.5 vs. GPT-6.1 Terra
- 54GPT-5.6 Terra vs. Gemini 3.1 Pro Preview
- 55Claude Opus 5.5 vs. GPT-5.4
- 56Claude Opus 5.5 vs. GLM-5.1
- 57GPT-5.6 Terra vs. GPT-5.4
- 58GPT-5.6 Terra vs. Gemini 4 Argon