Claude Sonnet 5.5 vs Kimi K3
Claude Sonnet 5.5 scores higher on the Models at Work leaderboard (84 vs 60 out of 100). Kimi K3 is about 1.7× cheaper per blended million tokens ($2.31 vs $4, one figure an Artificial Analysis estimate). On Artificial Analysis' independent Intelligence Index, Claude Sonnet 5.5 leads 56 to 44.
| Claude Sonnet 5.5 · Anthropic | Kimi K3 · Moonshot | |
|---|---|---|
| Leaderboard rank | #4 | #11 |
| Score (0–100) | 84 | 60 |
| Tier | Workhorse | Open weights |
| Price per 1M tokens | $2 in · $10 out | $2.31 blended (estimate) |
| Context window | 1M | Not verified |
| Open weights | No | Yes |
| Artificial Analysis Intelligence Index | 56 | 44 |
| Arena text score | — | 1488 |
| Best for | Production coding assistants, High-volume agents, Default model for most teams | Self-hosting, Open-licence requirements, Arena-style chat quality |
Choose Claude Sonnet 5.5 if…
- you need production coding assistants
- you need high-volume agents
- you need default model for most teams
The value pick of the table: second on the index at a fifth of the Opus price, and the fastest of the top five.
Choose Kimi K3 if…
- you need self-hosting
- you need open-licence requirements
- you need arena-style chat quality
The highest-placed open-licence model on Arena, and the one most teams have not tried yet.
Caveats: Price is Artificial Analysis' blended figure, not a vendor list price; context not verified from a primary source.
What practitioners say
Claude Sonnet 5.5: Less discussed than its siblings because it just works; the October cache-read price cut to $0.10 per million was the news.
Questions people ask
Which is better, Claude Sonnet 5.5 or Kimi K3?
Claude Sonnet 5.5 scores higher on the Models at Work leaderboard (84 vs 60 out of 100). Kimi K3 is about 1.7× cheaper per blended million tokens ($2.31 vs $4, one figure an Artificial Analysis estimate). On Artificial Analysis' independent Intelligence Index, Claude Sonnet 5.5 leads 56 to 44.
When should I choose Claude Sonnet 5.5 over Kimi K3?
Choose Claude Sonnet 5.5 for production coding assistants, high-volume agents, default model for most teams. The value pick of the table: second on the index at a fifth of the Opus price, and the fastest of the top five.
When should I choose Kimi K3 over Claude Sonnet 5.5?
Choose Kimi K3 for self-hosting, open-licence requirements, arena-style chat quality. The highest-placed open-licence model on Arena, and the one most teams have not tried yet.
Which is cheaper, Claude Sonnet 5.5 or Kimi K3?
Claude Sonnet 5.5 costs $2 per million input tokens and $10 per million output tokens on Anthropic's list price (Claude pricing, read Oct 10, 2026). Moonshot does not publish a simple list price for Kimi K3; Artificial Analysis estimates a blended $2.31 per million tokens (three input to one output).
Scores come from the Models at Work leaderboard: Score is 0 to 100: 50% independent evals normalised within this table, 20% price-performance, 15% practitioner sentiment from Signals and community threads, 15% operational fit (context, speed, availability, open weights). Models within three points are a tie in practice. Vendor-published figures are labelled as such and never counted as independent. Prices are vendor list prices where published; blended figures assume three input tokens per output token.