Poolside Laguna S 2.1: A Powerful Free AI Coding Model
Poolside has released Laguna S 2.1, a strong open-weight coding model now available for free (limited time) on platforms like OpenRouter. Built specifically for agentic coding and long-horizon software engineering tasks, it delivers impressive performance relative to its size.
Key Specs
- Architecture: 118B total parameters (Mixture-of-Experts) with only 8B active per token
- Context: Up to 262K tokens on the free tier (1M on paid)
- Benchmarks: 70.2% on Terminal-Bench 2.1 and solid results on SWE-related evaluations
- License: OpenMDW-1.1 (open weights available on Hugging Face)
- Features: Native reasoning (thinking on/off), strong tool use, and excellent for multi-step coding workflows
Why It Stands Out
Laguna S 2.1 punches above its weight class. It handles code reviews, comparisons, debugging, and agent-style tasks quickly and accurately. In practical tests it efficiently compares multiple code reviews, identifies common issues (including UI/theme problems), and produces clear summaries. Many coding tools and agents already support it.
How to Use It
Access the free version via OpenRouter (poolside/laguna-s-2.1:free) in tools like Kilocode, Cursor, Continue, or any OpenAI-compatible client. Just add your API key and select the model. Note that free tiers can have rate limits and may be temporary — earlier free Poolside models have been retired or moved to paid.
