Model Comparison

Claude 3 Opus vs GPT-5.6 TerraWhich is better in 2026?

GPT-5.6 Terra significantly outperforms across most benchmarks. GPT-5.6 Terra is 5.3x cheaper per token.

Verdict: Claude 3 Opus vs GPT-5.6 Terra — which is better?

Claude 3 Opus (by Anthropic) and GPT-5.6 Terra (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude 3 Opus outperforms in 0 benchmarks, while GPT-5.6 Terra is better at 1 benchmark (GPQA). GPT-5.6 Terra significantly outperforms across most benchmarks.

On price, GPT-5.6 Terra is roughly 5.3x 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.

Choose Claude 3 Opus if…

  • you want predictable pricing at $15.00/M input and $75.00/M output

Choose GPT-5.6 Terra if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • cost matters — it's about 5.3x cheaper per token
  • you process long inputs — it offers a 1,050,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude 3 Opus outperforms in 0 benchmarks, while GPT-5.6 Terra is better at 1 benchmark (GPQA).

GPT-5.6 Terra significantly outperforms across most benchmarks.

Sat Jul 18 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT-5.6 Terra costs less

For input processing, Claude 3 Opus ($15.00/1M tokens) is 6.0x more expensive than GPT-5.6 Terra ($2.50/1M tokens).

For output processing, Claude 3 Opus ($75.00/1M tokens) is 5.0x more expensive than GPT-5.6 Terra ($15.00/1M tokens).

In conclusion, Claude 3 Opus is more expensive than GPT-5.6 Terra.*

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

Lowest available price from all providers
Sat Jul 18 2026 • llm-stats.com
Anthropic
Claude 3 Opus
Input tokens$15.00
Output tokens$75.00
Best providerAnthropic
OpenAI
GPT-5.6 Terra
Input tokens$2.50
Output tokens$15.00
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 3 Opus's 200,000 tokens. Claude 3 Opus can generate longer responses up to 200,000 tokens, while GPT-5.6 Terra is limited to 128,000 tokens.

Anthropic
Claude 3 Opus
Input200,000 tokens
Output200,000 tokens
OpenAI
GPT-5.6 Terra
Input1,050,000 tokens
Output128,000 tokens
Sat Jul 18 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude 3 Opus and GPT-5.6 Terra support multimodal inputs.

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

Claude 3 Opus

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 3 Opus

Proprietary

Closed source

GPT-5.6 Terra

Proprietary

Closed source

Release Timeline

When each model was launched

Claude 3 Opus was released on 2024-02-29, while GPT-5.6 Terra was released on 2026-07-09.

GPT-5.6 Terra is 29 months newer than Claude 3 Opus.

Claude 3 Opus

Feb 29, 2024

2.4 years ago

GPT-5.6 Terra

Jul 9, 2026

1 weeks ago

2.4yr newer

Knowledge Cutoff

When training data ends

GPT-5.6 Terra has a documented knowledge cutoff of 2026-02-16, while Claude 3 Opus'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 3 Opus's cutoff date.

Claude 3 Opus

GPT-5.6 Terra

Feb 2026

Provider Availability

Claude 3 Opus is available from Anthropic, Bedrock, Google. GPT-5.6 Terra is available from OpenAI.

Claude 3 Opus

anthropic logo
Anthropic
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
bedrock logo
AWS Bedrock
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M
google logo
Google
Input Price:Input: $15.00/1MOutput Price:Output: $75.00/1M

GPT-5.6 Terra

openai logo
OpenAI
Input Price:Input: $2.50/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Key Takeaways

No standout differentiators in the data we have for this pair.

Larger context window (1,050,000 tokens)
Less expensive input tokens
Less expensive output tokens
Higher GPQA score (92.9% vs 50.4%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude 3 Opus and GPT-5.6 Terra side-by-side, then vote on the output you prefer.

Claude 3 Opus
✓ Preferred
GPT-5.6 Terra
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude 3 Opus
OpenAI
GPT-5.6 Terra

FAQ

Common questions about Claude 3 Opus vs GPT-5.6 Terra.

Which is better, Claude 3 Opus or GPT-5.6 Terra?

GPT-5.6 Terra significantly outperforms across most benchmarks. Claude 3 Opus is made by Anthropic and GPT-5.6 Terra is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude 3 Opus compare to GPT-5.6 Terra in benchmarks?

Claude 3 Opus scores ARC-C: 96.4%, HellaSwag: 95.4%, GSM8k: 95.0%, MGSM: 90.7%, BIG-Bench Hard: 86.8%. 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 3 Opus cheaper than GPT-5.6 Terra?

GPT-5.6 Terra is 6.0x cheaper for input tokens. Claude 3 Opus costs $15.00/M input and $75.00/M output via anthropic. GPT-5.6 Terra costs $2.50/M input and $15.00/M output via openai.

What are the context window sizes for Claude 3 Opus and GPT-5.6 Terra?

Claude 3 Opus supports 200K 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 3 Opus and GPT-5.6 Terra?

Key differences include context window (200K vs 1.1M), input pricing ($15.00 vs $2.50/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude 3 Opus and GPT-5.6 Terra?

Claude 3 Opus is developed by Anthropic and GPT-5.6 Terra is developed by OpenAI.