Best open-weight AI models

Models whose weights are published, so you can run them on your own hardware or pick among many API providers. Ranked by the overall index from Epoch AI’s independent tests.

Updated September 30, 2026

Our picks

#ModelOverall indexiInputiOutputiContexti
1
Kimi K3Moonshot AI
157.7
$3$151M
2
GLM 5.3Z.ai (Zhipu)
155.6
$1.40$4.401M
3
155.4
$0.66$1.981M
4
155.0
$0.30$1.201M
5
154.5
$0.018$0.321M
6
GLM 5.3 FlashZ.ai (Zhipu)
151.9
$0.15$0.501M
7
GLM 5.2Z.ai (Zhipu)
151.8
$0.14$3.991M
8
Kimi K2.6Moonshot AI
151.0
$0.65$3.41256K
9
Inkling SmallThinking Machines Lab
150.1
$0.45$1.20512K
10
Kimi K2.7 CodeMoonshot AI
150.0
$0.66$3.30256K

per 1M tokens · USD

Quick answers

What is the best open-source AI model?
Kimi K3 from Moonshot AI leads this ranking (Overall index: 157.7). It costs $3 per million input tokens and $15 per million output tokens.
Is there a cheaper alternative?
DeepSeek V4 Flash 0731 from DeepSeek (Overall index: 154.5) costs $0.018 / $0.32 per million tokens, about 64× less than Kimi K3.

How we rank

Scores come from tests run independently by Epoch AI (CC BY 4.0), not from the companies’ own announcements. Prices come from OpenRouter’s public API. Both are refreshed automatically several times a day, so this ranking follows new releases and price changes.

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