Cheapest agent LLMs
The cheapest LLMs that score well on agentic benchmarks. Ranked by price per 1M input tokens.
Ranked by input price
Models with agent benchmark scores, cheapest first.
Top 3 cheapest agent LLMs
Gemma 4 26B A4B (free) has agentic scores (SWE-bench, tau-bench, WebArena) and lands at $0.00 per 1M input tokens. Useful when agent loops spike token spend.
Gemma 4 31B (free) has agentic scores (SWE-bench, tau-bench, WebArena) and lands at $0.00 per 1M input tokens. Useful when agent loops spike token spend.
gpt-oss-120b (free) has agentic scores (SWE-bench, tau-bench, WebArena) and lands at $0.00 per 1M input tokens. Useful when agent loops spike token spend.
The price gap · cheapest vs most expensive
Premium agent models pay for more reliable tool use, fewer hallucinated tool names, and longer-horizon planning. For simple tool loops, the cheap end works fine.