K2 Horizon 0.9B vs Mercury 3
Mercury 3 leads the LLM Stats Score 35.9 to 0.5.
Institute of Foundation Models · Inception · Updated for 2026
Which is better?
Mercury 3 leads the overall LLM Stats Score 35.9 to 0.5, ranking #103 overall.
In the 1 individual benchmarks reported for both models, Mercury 3 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 K2 Horizon 0.9B
- you need open weights you can self-host or fine-tune
Choose Mercury 3
- overall performance matters — it scores 35.9 and ranks #103 on LLM Stats
- your work emphasizes reasoning and agents — it leads those capability indexes
- you value its reported benchmark strengths — it wins 1 of 1 exact shared results
- you want the most recent training data — it shipped Oct 2026
At a glance
The differences that matter most.
Individual benchmarks
8 reported for K2 Horizon 0.9B · 12 for Mercury 3
K2 Horizon 0.9B outperforms in 0 benchmarks, while Mercury 3 is better at 1 benchmark (GPQA).
Mercury 3 significantly outperforms across most benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Context Window
Maximum input and output token capacity
Only Mercury 3 specifies input context (1,000,000 tokens). Only Mercury 3 specifies output context (131,072 tokens).
License
Usage and distribution terms
K2 Horizon 0.9B is licensed under Apache 2.0, while Mercury 3 uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
Apache 2.0
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
K2 Horizon 0.9B was released on 2026-09-03, while Mercury 3 was released on 2026-10-19.
Mercury 3 is 2 months newer than K2 Horizon 0.9B.
Sep 3, 2026
1 months ago
Oct 19, 2026
1 weeks ago
1mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Outputs Comparison
Judge for yourself.
Run your own prompts against K2 Horizon 0.9B and Mercury 3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about K2 Horizon 0.9B vs Mercury 3.