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GPT-6.1 Terra vs K2 Horizon 0.9B

GPT-6.1 Terra leads the LLM Stats Score 47.5 to 0.5.

OpenAI · Institute of Foundation Models · Updated for 2026

Which is better?

GPT-6.1 Terra leads the overall LLM Stats Score 47.5 to 0.5, ranking #36 overall.

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

Choose GPT-6.1 Terra

  • overall performance matters — it scores 47.5 and ranks #36 on LLM Stats
  • your work emphasizes reasoning and agents — it leads those capability indexes
  • you want the most recent training data — it shipped Oct 2026

Choose K2 Horizon 0.9B

  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

GPT-6.1 Terra
OpenAI
K2 Horizon 0.9B
Institute of Foundation Models
Core performance indexes
LLM Stats Score
47.5
#36
0.5
#358
Reasoning
49.0
#19
0.6
#350
Agents
38.8
#12
-5.3
#218
Cost, coverage & limits
Benchmark wins
—
—
Input price
$1.00 / M
— / M
Output price
$5.00 / M
— / M
Context window
1,050,000
—

Individual benchmarks

8 reported for GPT-6.1 Terra · 8 for K2 Horizon 0.9B

No common benchmarks found

GPT-6.1 Terra and K2 Horizon 0.9Bdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-6.1 Terra specifies input context (1,050,000 tokens). Only GPT-6.1 Terra specifies output context (128,000 tokens).

OpenAI
GPT-6.1 Terra
Input1,050,000 tokens
Output128,000 tokens
Institute of Foundation Models
K2 Horizon 0.9B
Input- tokens
Output- tokens
Fri Oct 30 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-6.1 Terra supports multimodal inputs, whereas K2 Horizon 0.9B does not.

GPT-6.1 Terra can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-6.1 Terra

Text
Images
Audio
Video

K2 Horizon 0.9B

Text
Images
Audio
Video

License

Usage and distribution terms

GPT-6.1 Terra is licensed under a proprietary license, while K2 Horizon 0.9B uses Apache 2.0.

License differences may affect how you can use these models in commercial or open-source projects.

GPT-6.1 Terra

Proprietary

Closed source

K2 Horizon 0.9B

Apache 2.0

Open weights

Release Timeline

When each model was launched

GPT-6.1 Terra was released on 2026-10-26, while K2 Horizon 0.9B was released on 2026-09-03.

GPT-6.1 Terra is 2 months newer than K2 Horizon 0.9B.

GPT-6.1 Terra

Oct 26, 2026

-1 days ago

1mo newer
K2 Horizon 0.9B

Sep 3, 2026

1 months ago

Knowledge Cutoff

When training data ends

GPT-6.1 Terra has a documented knowledge cutoff of 2026-06-01, while K2 Horizon 0.9B's cutoff date is not specified.

We can confirm GPT-6.1 Terra's training data extends to 2026-06-01, but cannot make a direct comparison without K2 Horizon 0.9B's cutoff date.

GPT-6.1 Terra

Jun 2026

K2 Horizon 0.9B

—

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against GPT-6.1 Terra and K2 Horizon 0.9B side-by-side, then vote on the output you prefer.

GPT-6.1 Terra
✓ Preferred
K2 Horizon 0.9B
Open in Playground

FAQ

Common questions about GPT-6.1 Terra vs K2 Horizon 0.9B.

Which is better, GPT-6.1 Terra or K2 Horizon 0.9B?

GPT-6.1 Terra leads the LLM Stats Score 47.5 to 0.5. GPT-6.1 Terra is made by OpenAI and K2 Horizon 0.9B is made by Institute of Foundation Models. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does GPT-6.1 Terra compare to K2 Horizon 0.9B in benchmarks?

GPT-6.1 Terra scores HealthBench Consensus: 95.1%, HealthBench Professional: 62.7%, Agents' Last Exam: 60.0%, Terminal-Bench-Science 0.1: 58.3%, MentalHealthBench: 55.5%. K2 Horizon 0.9B scores HumanEval+: 79.9%, MBPP+: 68.0%, AIME 2026: 48.5%, AIME 2025: 41.7%, LiveCodeBench v6: 37.4%.

What are the context window sizes for GPT-6.1 Terra and K2 Horizon 0.9B?

GPT-6.1 Terra supports 1.1M tokens and K2 Horizon 0.9B supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between GPT-6.1 Terra and K2 Horizon 0.9B?

Key differences include LLM Stats Score (47.5 vs 0.5), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-6.1 Terra and K2 Horizon 0.9B?

GPT-6.1 Terra is developed by OpenAI and K2 Horizon 0.9B is developed by Institute of Foundation Models.

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