Cheapest frontier-class LLMs
OpenAI: GPT-6.1 Terra is the cheapest option at $1.00 per million input tokens. Models scoring in the top tier on published intelligence benchmarks, ranked by price. This is the list for the question that actually matters: the least you can pay for frontier-level capability.
6 models qualify
Ranked by blended cost - input weighted 75%, output 25%.
| # | Model | Blended / 1M | Input / 1M | Output / 1M | Context | Capabilities |
|---|---|---|---|---|---|---|
| 1 | GPT-6.1 Terra OpenAI | $2.00 | $1.00 | $5.00 | 1.1M | ReasoningToolsVision |
| 2 | Gemini 4 Argon | $4.00 | $2.00 | $10.00 | 1.0M | ReasoningToolsVision |
| 3 | GPT-6.1 Sol OpenAI | $4.00 | $2.00 | $10.00 | 1.1M | ReasoningToolsVision |
| 4 | Claude Sonnet 5.5 Anthropic | $4.00 | $2.00 | $10.00 | 1M | ReasoningToolsVision |
| 5 | Claude Opus 5.5 Anthropic | $8.00 | $4.00 | $20.00 | 1M | ReasoningToolsVision |
| 6 | GPT-6 Astra OpenAI | $20.00 | $10.00 | $50.00 | 1.1M | ReasoningToolsVision |
Frequently asked
What is the cheapest LLM for frontier-level capability?
OpenAI: GPT-6.1 Terra at $1.00 per million input tokens and $5.00 per million output tokens, with a 1.1M token context window.
How many models qualify for frontier-level capability?
6 of the 359 models tracked here meet the criteria for this list.
How much do prices vary within this category?
By roughly 10×, from GPT-6.1 Terra at the bottom to GPT-6 Astra at the top.