Cheapest reasoning LLMs
inclusionAI: Ling 3.0 Flash is the cheapest option at $0.021 per million input tokens. Reasoning models emit far more output tokens than they take in, so output price dominates the bill. These are ranked with that weighting in mind.
245 models qualify
Ranked by output price, because reasoning models bill mostly on tokens they generate.
| # | Model | Blended / 1M | Input / 1M | Output / 1M | Context | Capabilities |
|---|---|---|---|---|---|---|
| 1 | Jev Router TypeSafe | $-1000000.0000 | $-1000000.0000 | $-1000000.0000 | 1M | ReasoningToolsVision |
| 2 | Auto Router (Beta) OpenRouter | $-1000000.0000 | $-1000000.0000 | $-1000000.0000 | 2M | ReasoningToolsVision |
| 3 | Pareto Code Router OpenRouter | $-1000000.0000 | $-1000000.0000 | $-1000000.0000 | 2M | ReasoningTools |
| 4 | Auto Router OpenRouter | $-1000000.0000 | $-1000000.0000 | $-1000000.0000 | 2M | ReasoningToolsVision |
| 5 | Flint (free) Recursive | Free | Free | Free | 262K | Free tierReasoningToolsOpen weights |
| 6 | Xing4.0 29B A4B (free) XingChen | Free | Free | Free | 262K | Free tierReasoningToolsOpen weights |
| 7 | Dots3-Note Preview (free) Dots Studio | Free | Free | Free | 512K | Free tierReasoningToolsVision |
| 8 | North Mini Code (free) Cohere | Free | Free | Free | 256K | Free tierReasoningToolsOpen weights |
| 9 | Free | Free | Free | 256K | Free tierReasoningToolsVisionOpen weights | |
| 10 | Free Models Router OpenRouter | Free | Free | Free | 200K | Free tierReasoningToolsVision |
| 11 | Ling 3.0 Flash inclusionAI | $0.032 | $0.021 | $0.063 | 262K | ReasoningToolsOpen weights |
| 12 | gpt-oss-20b OpenAI | $0.036 | $0.018 | $0.090 | 131K | ReasoningToolsOpen weights |
| 13 | Nex-N2.5-Mini Nex AGI | $0.044 | $0.025 | $0.100 | 262K | ReasoningVisionOpen weights |
| 14 | Laguna XS 2.1 Poolside | $0.075 | $0.060 | $0.120 | 262K | Free tierReasoningToolsOpen weights |
| 15 | Ternary Bonsai 2 9B PrismML | $0.092 | $0.080 | $0.130 | 262K | ReasoningToolsVisionOpen weights |
| 16 | Qwen3.7 Flash Qwen | $0.055 | $0.030 | $0.130 | 1M | ReasoningToolsVision |
| 17 | Mercury 2.5 Inception | $0.068 | $0.040 | $0.150 | 260K | ReasoningTools |
| 18 | Granite 4.2 8B IBM Granite | $0.082 | $0.060 | $0.150 | 131K | ReasoningToolsOpen weights |
| 19 | Ling 3.0 Flash VL inclusionAI | $0.090 | $0.060 | $0.180 | 131K | ReasoningToolsVisionOpen weights |
| 20 | Laguna S 2.1 Poolside | $0.113 | $0.090 | $0.180 | 1.0M | Free tierReasoningToolsOpen weights |
| 21 | DeepSeek V4 Flash 0423 DeepSeek | $0.114 | $0.091 | $0.182 | 1.0M | ReasoningToolsOpen weights |
| 22 | Solar Mini 4 Upstage | $0.087 | $0.050 | $0.200 | 524K | ReasoningTools |
| 23 | $0.125 | $0.100 | $0.200 | 1.0M | ReasoningToolsVision | |
| 24 | $0.125 | $0.100 | $0.200 | 1.0M | ReasoningToolsVision | |
| 25 | Nemotron 3.5 Lightning NVIDIA | $0.103 | $0.070 | $0.200 | 262K | Free tierReasoningToolsOpen weights |
Frequently asked
What is the cheapest LLM for step-by-step reasoning?
inclusionAI: Ling 3.0 Flash at $0.021 per million input tokens and $0.063 per million output tokens, with a 262K token context window.
How many models qualify for step-by-step reasoning?
245 of the 358 models tracked here meet the criteria for this list.
How much do prices vary within this category?
By roughly 2,100×, from Ling 3.0 Flash at the bottom to GPT-5.4 Pro at the top.