The AI arena is free today

Open Superagent

K2 Horizon 7B vs Solar Pro 4

Solar Pro 4 leads the LLM Stats Score 33.9 to 25.7.

Institute of Foundation Models · Upstage · Updated for 2026

Which is better?

Solar Pro 4 leads the overall LLM Stats Score 33.9 to 25.7, ranking #117 overall.

In the 5 individual benchmarks reported for both models, Solar Pro 4 wins 3; 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 K2 Horizon 7B

  • you want the most recent training data — it shipped Sep 2026
  • you need open weights you can self-host or fine-tune

Choose Solar Pro 4

  • overall performance matters — it scores 33.9 and ranks #117 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 3 of 5 exact shared results

At a glance

The differences that matter most.

K2 Horizon 7B
Institute of Foundation Models
Solar Pro 4
Upstage
Core performance indexes
LLM Stats Score
25.7
#184
33.9
#117
Reasoning
25.6
#181
33.5
#116
Coding
8.4
#209
20.4
#121
Agents
12.0
#133
10.8
#143
Cost, coverage & limits
Benchmark wins
2 of 5
3 of 5
Input price
— / M
$0.30 / M
Output price
— / M
$1.20 / M
Context window
—
524,288

Capability indexes

Additional strengths measured across groups of related public benchmarks

2 shared
Index
K2 Horizon 7B
Solar Pro 4
Math
14.4#235
32.1#67
Tool use
8.4#164
8.9#160
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

8 reported for K2 Horizon 7B · 9 for Solar Pro 4

5 shared

K2 Horizon 7B outperforms in 2 benchmarks (BrowseComp, Tau3 Banking), while Solar Pro 4 is better at 2 benchmarks (AA-LCR, Terminal-Bench 2.1).

Both models are evenly matched across the benchmarks.

Fri Oct 30 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Solar Pro 4 specifies input context (524,288 tokens). Only Solar Pro 4 specifies output context (131,072 tokens).

Institute of Foundation Models
K2 Horizon 7B
Input- tokens
Output- tokens
Upstage
Solar Pro 4
Input524,288 tokens
Output131,072 tokens
Fri Oct 30 2026 • llm-stats.com

License

Usage and distribution terms

K2 Horizon 7B is licensed under Apache 2.0, while Solar Pro 4 uses a proprietary license.

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

K2 Horizon 7B

Apache 2.0

Open weights

Solar Pro 4

Proprietary

Closed source

Release Timeline

When each model was launched

K2 Horizon 7B was released on 2026-09-03, while Solar Pro 4 was released on 2026-08-06.

K2 Horizon 7B is 1 month newer than Solar Pro 4.

K2 Horizon 7B

Sep 3, 2026

1 months ago

4w newer
Solar Pro 4

Aug 6, 2026

2 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against K2 Horizon 7B and Solar Pro 4 side-by-side, then vote on the output you prefer.

K2 Horizon 7B
✓ Preferred
Solar Pro 4
Open in Playground

FAQ

Common questions about K2 Horizon 7B vs Solar Pro 4.

Which is better, K2 Horizon 7B or Solar Pro 4?

Solar Pro 4 leads the LLM Stats Score 33.9 to 25.7. K2 Horizon 7B is made by Institute of Foundation Models and Solar Pro 4 is made by Upstage. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does K2 Horizon 7B compare to Solar Pro 4 in benchmarks?

K2 Horizon 7B scores HMMT Feb 26: 73.3%, SWE-Bench Verified: 70.6%, AA-LCR: 68.0%, BrowseComp: 59.0%, Terminal-Bench 2.1: 39.1%. Solar Pro 4 scores AIME 2026: 95.3%, GPQA: 89.0%, LiveCodeBench: 87.8%, MMLU-Pro: 86.3%, AA-LCR: 71.0%.

What are the context window sizes for K2 Horizon 7B and Solar Pro 4?

K2 Horizon 7B supports an unknown number of tokens and Solar Pro 4 supports 524K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between K2 Horizon 7B and Solar Pro 4?

Key differences include LLM Stats Score (25.7 vs 33.9), licensing (Apache 2.0 vs Proprietary). See the full comparison above for benchmark-by-benchmark results.

Who makes K2 Horizon 7B and Solar Pro 4?

K2 Horizon 7B is developed by Institute of Foundation Models and Solar Pro 4 is developed by Upstage.

Related comparisons