Aion-2.0
Reasoning model for deliberate analysis, multi-step problem solving, and tool use.
- Capability
- —No ECI score yet
- Input
- $0.80per 1M tokens
- Output
- $1.60per 1M tokens
- Context
- 131K33K max output
What it costs
- Input
- $0.80per million tokens
- Output
- $1.60per million tokens
- Blended (3:1)
- $1.00pricier than 57% of priced models
Typical monthly bills
| Monthly usage | Estimated cost |
|---|---|
| Side project2M input + 0.5M output tokens | $2.40 |
| Team assistant25M input + 5M output tokens | $28.00 |
| Production app250M input + 50M output tokens | $280.00 |
Median of 3 paid API providers on models.dev.
Independent benchmarks
Epoch AI has not published a Capabilities Index score for Aion-2.0 yet.
The details
- Lab
- Aion Labs
- Released
- Dec 21, 2025
- Context window
- 131,072 tokens
- Max output
- 32,768 tokens
- Inputs
- Text
- Output
- Text
- Reasoning
- Always on
- Tool calling
- Yes
- Structured output
- No
- Weights
- Proprietary
- Availability
- 3 API providerslisted on models.dev
More from Aion Labs
About Aion-2.0
How much does Aion-2.0 cost?
Aion-2.0 costs $0.80 input / $1.60 output per million tokens (median across 3 API providers). At a 3:1 input-to-output mix that is $1.00 per million tokens, more expensive than 57% of the 445 priced models we track.
What is the context window of Aion-2.0?
Aion-2.0 accepts up to 131,072 tokens per request and can write up to 32,768 tokens in one response.
How good is Aion-2.0?
Epoch AI has not published a Capabilities Index score for Aion-2.0 yet.
Is Aion-2.0 open source?
No. Aion-2.0 is proprietary; you use it through an API or partner platforms.
What inputs does Aion-2.0 support?
Aion-2.0 accepts text and replies in text. It is a reasoning model, supports tool calling.
When was Aion-2.0 released?
Aion Labs released Aion-2.0 on Dec 21, 2025.
What are the best alternatives to Aion-2.0?
The closest current models from other labs on capability, price and release date are Nova 2 Lite (Amazon, $0.315 / $2.63), Ling-1T (inclusionAI, $0.57 / $2.29), GLM-4.6 (Z.ai (Zhipu), $0.60 / $2.20) and Qwen3.5 122B-A10B (Alibaba (Qwen), $0.40 / $3.20).