Aion-2.0 vs Aion 3.5
API pricing, benchmark indices and specs — updated 19 October 2026.
aion-labs · A · API-only
Input / 1M
$0.80
Output / 1M
$1.60
AA index
—
proprietary · 131.1K context
aion-labs · B · API-only
Input / 1M
$3.00
Output / 1M
$6.00
AA index
—
proprietary · 262.1K context
Specification comparison
Differences are highlighted; identical values are muted.
| Specification | Aion-2.0 | Aion 3.5 |
|---|---|---|
| Deployment | API-only (closed weights) | API-only (closed weights) |
| Parameters | n/a — API-only | n/a — API-only |
| Architecture | n/a — API-only | n/a — API-only |
| Context length | 131,072 | 262,144 |
| Licence | Proprietary | Proprietary |
| Commercial use | Per API terms | Per API terms |
| Languages | n/a — API-only | n/a — API-only |
| Downloads 30d | n/a — API-only | n/a — API-only |
| Downloads all time | n/a — API-only | n/a — API-only |
| Quantizations on the Hub | n/a — API-only | n/a — API-only |
| Gated | n/a — API-only | n/a — API-only |
| First seen on the Hub | n/a — API-only | n/a — API-only |
| API input price / 1M tokens | $0.80 | $3.00 |
| API output price / 1M tokens | $1.60 | $6.00 |
| Est. cost per 1M input + 1M output tokens | $2.40 | $9.00 |
| Cached input / 1M tokens | $0.20 | $0.75 |
| AA Intelligence Index | — | — |
| AA Coding Index | — | — |
| AA Agentic Index | — | — |
| Max output tokens | 32,768 | 32,768 |
| API providers | 1 | 1 |
| Tool calling | Yes | Yes |
| Reasoning mode | Yes | Yes |
API cost
Estimated cost of 1M input + 1M output tokens via OpenRouter
Aion-2.0
$2.40
Aion 3.5
$9.00
Aion-2.0 is 3.7× cheaper at list price.