Model Comparison

Gemini 1.5 Pro vs GPT-5.6 TerraWhich is better in 2026?

GPT-5.6 Terra significantly outperforms across most benchmarks. Gemini 1.5 Pro is 1.3x cheaper per token.

Verdict: Gemini 1.5 Pro vs GPT-5.6 Terra — which is better?

Gemini 1.5 Pro (by Google) 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.

Gemini 1.5 Pro 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, Gemini 1.5 Pro is roughly 1.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 1.5 Pro also accepts a larger context window (2,097,152 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 1.5 Pro if…

  • cost matters — it's about 1.3x cheaper per token
  • you process long inputs — it offers a 2,097,152 token context window

Choose GPT-5.6 Terra if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you want the most recent training data — it shipped Jul 2026

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Gemini 1.5 Pro 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

Gemini 1.5 Pro costs less

For input processing, Gemini 1.5 Pro ($2.50/1M tokens) costs the same as GPT-5.6 Terra ($2.50/1M tokens).

For output processing, Gemini 1.5 Pro ($10.00/1M tokens) is 1.5x cheaper than GPT-5.6 Terra ($15.00/1M tokens).

In conclusion, GPT-5.6 Terra is more expensive than Gemini 1.5 Pro.*

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

Lowest available price from all providers
Sat Jul 18 2026 • llm-stats.com
Google
Gemini 1.5 Pro
Input tokens$2.50
Output tokens$10.00
Best providerGoogle
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

Gemini 1.5 Pro accepts 2,097,152 input tokens compared to GPT-5.6 Terra's 1,050,000 tokens. GPT-5.6 Terra can generate longer responses up to 128,000 tokens, while Gemini 1.5 Pro is limited to 8,192 tokens.

Google
Gemini 1.5 Pro
Input2,097,152 tokens
Output8,192 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 Gemini 1.5 Pro and GPT-5.6 Terra support multimodal inputs.

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

Gemini 1.5 Pro

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.

Gemini 1.5 Pro

Proprietary

Closed source

GPT-5.6 Terra

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 1.5 Pro was released on 2024-05-01, while GPT-5.6 Terra was released on 2026-07-09.

GPT-5.6 Terra is 27 months newer than Gemini 1.5 Pro.

Gemini 1.5 Pro

May 1, 2024

2.2 years ago

GPT-5.6 Terra

Jul 9, 2026

1 weeks ago

2.2yr newer

Knowledge Cutoff

When training data ends

Gemini 1.5 Pro has a knowledge cutoff of 2023-11-01, while GPT-5.6 Terra has a cutoff of 2026-02-16.

GPT-5.6 Terra has more recent training data (up to 2026-02-16), making it potentially better informed about events through that date compared to Gemini 1.5 Pro (2023-11-01).

Gemini 1.5 Pro

Nov 2023

GPT-5.6 Terra

Feb 2026

2.3 yr newer

Provider Availability

Gemini 1.5 Pro is available from Google. GPT-5.6 Terra is available from OpenAI.

Gemini 1.5 Pro

google logo
Google
Input Price:Input: $2.50/1MOutput Price:Output: $10.00/1M

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

Google
Larger context window (2,097,152 tokens)
Less expensive output tokens
OpenAI
Higher GPQA score (92.9% vs 59.1%)

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Gemini 1.5 Pro and GPT-5.6 Terra side-by-side, then vote on the output you prefer.

Gemini 1.5 Pro
✓ Preferred
GPT-5.6 Terra
Open in Playground
AI Model Comparison Table
Feature
Google
Gemini 1.5 Pro
OpenAI
GPT-5.6 Terra

FAQ

Common questions about Gemini 1.5 Pro vs GPT-5.6 Terra.

Which is better, Gemini 1.5 Pro or GPT-5.6 Terra?

GPT-5.6 Terra significantly outperforms across most benchmarks. Gemini 1.5 Pro is made by Google 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 Gemini 1.5 Pro compare to GPT-5.6 Terra in benchmarks?

Gemini 1.5 Pro scores XSTest: 98.8%, FLEURS: 93.3%, HellaSwag: 93.3%, GSM8k: 90.8%, BIG-Bench Hard: 89.2%. 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 Gemini 1.5 Pro cheaper than GPT-5.6 Terra?

Both models cost $2.50 per million input tokens.

What are the context window sizes for Gemini 1.5 Pro and GPT-5.6 Terra?

Gemini 1.5 Pro supports 2.1M 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 Gemini 1.5 Pro and GPT-5.6 Terra?

Key differences include context window (2.1M vs 1.1M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 1.5 Pro and GPT-5.6 Terra?

Gemini 1.5 Pro is developed by Google and GPT-5.6 Terra is developed by OpenAI.

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