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Claude Opus 5 vs GPT-5.6 Terra

Claude Opus 5 leads the LLM Stats Score 54.6 to 50.8. GPT-5.6 Terra is 2.2x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Opus 5 leads the overall LLM Stats Score 54.6 to 50.8, ranking #5 overall.

In the 8 individual benchmarks reported for both models, Claude Opus 5 wins 7; this is a narrower head-to-head signal than the composite indexes.

On price, GPT-5.6 Terra is roughly 2.2x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

GPT-5.6 Terra also accepts a larger context window (1,050,000 input tokens), making it the stronger choice for long documents and large codebases.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Opus 5

  • overall performance matters — it scores 54.6 and ranks #5 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 7 of 8 exact shared results
  • you want the most recent training data — it shipped Jul 2026

Choose GPT-5.6 Terra

  • cost matters — it's about 2.2x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window

At a glance

The differences that matter most.

Core performance indexes
54.6
#5
50.8
#14
53.5
#4
48.8
#18
41.8
#10
42.3
#7
39.3
#7
38.0
#11
Cost, coverage & limits
Benchmark wins
7 of 8
1 of 8
Input price
$5.00 / M
$2.00 / M
Output price
$25.00 / M
$12.00 / M
Context window
1,000,000
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
Claude Opus 5
GPT-5.6 Terra
37.9#4
29.9#30
25.6#27
26.9#23
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

13 reported for Claude Opus 5 · 45 for GPT-5.6 Terra

8 shared

Claude Opus 5 outperforms in 7 benchmarks (ARC-AGI-3, AutomationBench, BrowseComp, FrontierCode 1.1, HealthBench Professional, OSWorld 2.0, Terminal-Bench 4.0), while GPT-5.6 Terra is better at 1 benchmark (DeepSWE 1.1).

Claude Opus 5 significantly outperforms across most benchmarks.

Tue Sep 22 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT-5.6 Terra costs less

For input processing, Claude Opus 5 ($5.00/1M tokens) is 2.5x more expensive than GPT-5.6 Terra ($2.00/1M tokens).

For output processing, Claude Opus 5 ($25.00/1M tokens) is 2.1x more expensive than GPT-5.6 Terra ($12.00/1M tokens).

In conclusion, Claude Opus 5 is more expensive than GPT-5.6 Terra.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Sep 22 2026 • llm-stats.com
Anthropic
Claude Opus 5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT-5.6 Terra
Input tokens$2.00
Output tokens$12.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

GPT-5.6 Terra accepts 1,050,000 input tokens compared to Claude Opus 5's 1,000,000 tokens. Both models can generate responses up to 128,000 tokens.

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT-5.6 Terra
Input1,050,000 tokens
Output128,000 tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5 and GPT-5.6 Terra support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Opus 5

Text
Images
Audio
Video

GPT-5.6 Terra

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Opus 5

Proprietary

Closed source

GPT-5.6 Terra

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while GPT-5.6 Terra was released on 2026-07-09.

Claude Opus 5 is 1 month newer than GPT-5.6 Terra.

Claude Opus 5

Jul 24, 2026

2 months ago

2w newer
GPT-5.6 Terra

Jul 9, 2026

2 months ago

Knowledge Cutoff

When training data ends

GPT-5.6 Terra has a documented knowledge cutoff of 2026-02-16, while Claude Opus 5's cutoff date is not specified.

We can confirm GPT-5.6 Terra's training data extends to 2026-02-16, but cannot make a direct comparison without Claude Opus 5's cutoff date.

Claude Opus 5

GPT-5.6 Terra

Feb 2026

Provider Availability

Claude Opus 5 is available from Anthropic, DeepInfra. GPT-5.6 Terra is available from OpenAI.

Claude Opus 5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M
deepinfra logo
Deepinfra
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

GPT-5.6 Terra

openai logo
OpenAI
Input Price:Input: $2.00/1MOutput Price:Output: $12.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against Claude Opus 5 and GPT-5.6 Terra side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
GPT-5.6 Terra
Open in Playground

FAQ

Common questions about Claude Opus 5 vs GPT-5.6 Terra.

Which is better, Claude Opus 5 or GPT-5.6 Terra?

Claude Opus 5 leads the LLM Stats Score 54.6 to 50.8. Claude Opus 5 is made by Anthropic and GPT-5.6 Terra is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 5 compare to GPT-5.6 Terra in benchmarks?

Claude Opus 5 scores BrowseComp: 90.8%, BioMysteryBench: 90.1%, OSWorld 2.0: 70.6%, DeepSWE 1.1: 68.8%, Humanity's Last Exam: 64.7%. GPT-5.6 Terra scores Connectors: 100.0%, HealthBench Consensus: 95.1%, Search and Function-Calling: 94.6%, GPQA: 92.9%, Capture-the-Flag Challenges (Internal): 91.8%.

Is Claude Opus 5 cheaper than GPT-5.6 Terra?

GPT-5.6 Terra is 2.5x cheaper for input tokens. Claude Opus 5 costs $5.00/M input and $25.00/M output via anthropic. GPT-5.6 Terra costs $2.00/M input and $12.00/M output via openai.

What are the context window sizes for Claude Opus 5 and GPT-5.6 Terra?

Claude Opus 5 supports 1.0M tokens and GPT-5.6 Terra supports 1.1M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Opus 5 and GPT-5.6 Terra?

Key differences include LLM Stats Score (54.6 vs 50.8), context window (1.0M vs 1.1M), input pricing ($5.00 vs $2.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5 and GPT-5.6 Terra?

Claude Opus 5 is developed by Anthropic and GPT-5.6 Terra is developed by OpenAI.