GPT-5 High vs K2 Horizon 375B-A23B
GPT-5 High and K2 Horizon 375B-A23B are closely matched at 33.4 and 38.5 on the LLM Stats Score.
OpenAI · Institute of Foundation Models · Updated for 2026
Which is better?
GPT-5 High and K2 Horizon 375B-A23B are closely matched on the overall LLM Stats Score at 33.4 and 38.5.
In the 1 individual benchmarks reported for both models, K2 Horizon 375B-A23B wins 1; this is a narrower head-to-head signal than the composite indexes.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5 High
- you want predictable pricing at $1.25/M input and $10.00/M output
Choose K2 Horizon 375B-A23B
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- you want the most recent training data — it shipped Sep 2026
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Individual benchmarks
2 reported for GPT-5 High · 18 for K2 Horizon 375B-A23B
GPT-5 High outperforms in 0 benchmarks, while K2 Horizon 375B-A23B is better at 0 benchmarks.
Both models are evenly matched across the benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Only GPT-5 High specifies input context (400,000 tokens). Only GPT-5 High specifies output context (128,000 tokens).
Input capabilities
Documented input modalities across available providers
GPT-5 High supports multimodal inputs, whereas K2 Horizon 375B-A23B does not.
GPT-5 High can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-5 High
K2 Horizon 375B-A23B
License
Usage and distribution terms
GPT-5 High is licensed under a proprietary license, while K2 Horizon 375B-A23B uses Apache 2.0.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Apache 2.0
Open weights
Release Timeline
When each model was launched
GPT-5 High was released on 2025-08-07, while K2 Horizon 375B-A23B was released on 2026-09-03.
K2 Horizon 375B-A23B is 13 months newer than GPT-5 High.
Aug 7, 2025
1.2 years ago
Sep 3, 2026
1 months ago
1.1yr newerKnowledge Cutoff
When training data ends
GPT-5 High has a documented knowledge cutoff of 2024-09-30, while K2 Horizon 375B-A23B's cutoff date is not specified.
We can confirm GPT-5 High's training data extends to 2024-09-30, but cannot make a direct comparison without K2 Horizon 375B-A23B's cutoff date.
Sep 2024
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Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5 High and K2 Horizon 375B-A23B side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5 High vs K2 Horizon 375B-A23B.