Model Comparison
Kimi K3 vs Claude Opus 4.8Which is better in 2026?
Kimi K3 shows notably better performance in the majority of benchmarks. Kimi K3 is 1.7x cheaper per token.
Verdict: Kimi K3 vs Claude Opus 4.8 — which is better?
Kimi K3 (by Moonshot AI) and Claude Opus 4.8 (by Anthropic) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Kimi K3 outperforms in 7 benchmarks (BrowseComp, CharXiv-R, DeepSearchQA, FrontierSWE, GDPval-AA, MCP Atlas, Toolathlon), while Claude Opus 4.8 is better at 3 benchmarks (GPQA, Humanity's Last Exam, OfficeQA Pro). Kimi K3 shows notably better performance in the majority of benchmarks.
On price, Kimi K3 is roughly 1.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K3 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose Kimi K3 if…
- you want the strongest raw capability — it leads on 7 of 10 shared benchmarks
- cost matters — it's about 1.7x cheaper per token
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Jul 2026
Choose Claude Opus 4.8 if…
- you want predictable pricing at $5.00/M input and $25.00/M output
Performance Benchmarks
Comparative analysis across standard metrics
Kimi K3 outperforms in 7 benchmarks (BrowseComp, CharXiv-R, DeepSearchQA, FrontierSWE, GDPval-AA, MCP Atlas, Toolathlon), while Claude Opus 4.8 is better at 3 benchmarks (GPQA, Humanity's Last Exam, OfficeQA Pro).
Kimi K3 shows notably better performance in the majority of benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Kimi K3 ($3.00/1M tokens) is 1.7x cheaper than Claude Opus 4.8 ($5.00/1M tokens).
For output processing, Kimi K3 ($15.00/1M tokens) is 1.7x cheaper than Claude Opus 4.8 ($25.00/1M tokens).
In conclusion, Claude Opus 4.8 is more expensive than Kimi K3.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Kimi K3 accepts 1,048,576 input tokens compared to Claude Opus 4.8's 1,000,000 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while Claude Opus 4.8 is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
Both Kimi K3 and Claude Opus 4.8 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Kimi K3
Claude Opus 4.8
Release Timeline
When each model was launched
Kimi K3 was released on 2026-07-16, while Claude Opus 4.8 was released on 2026-05-28.
Kimi K3 is 2 months newer than Claude Opus 4.8.
Jul 16, 2026
1 days ago
1mo newerMay 28, 2026
1 months ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Kimi K3 is available from Moonshot AI. Claude Opus 4.8 is available from Anthropic, Vertex AI.
Kimi K3
Claude Opus 4.8
Outputs Comparison
Key Takeaways
Kimi K3
View detailsMoonshot AI
Claude Opus 4.8
View detailsAnthropic
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Kimi K3 and Claude Opus 4.8 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Kimi K3 vs Claude Opus 4.8.