Claude Opus 4.8 vs Kimi K3
Claude Opus 4.8 and Kimi K3 are closely matched at 51.5 and 54.6 on the LLM Stats Score. Kimi K3 is 1.7x cheaper per token.
Anthropic · Moonshot AI · Updated for 2026
Which is better?
Claude Opus 4.8 and Kimi K3 are closely matched on the overall LLM Stats Score at 51.5 and 54.6.
In the 10 individual benchmarks reported for both models, Kimi K3 wins 7; this is a narrower head-to-head signal than the composite indexes.
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.
Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose Claude Opus 4.8
- you want predictable pricing at $5.00/M input and $25.00/M output
Choose Kimi K3
- your work emphasizes agents — it leads those capability indexes
- you value its reported benchmark strengths — it wins 7 of 10 exact shared results
- 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
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
26 reported for Claude Opus 4.8 · 31 for Kimi K3
Claude Opus 4.8 outperforms in 3 benchmarks (GPQA, Humanity's Last Exam, OfficeQA Pro), while Kimi K3 is better at 7 benchmarks (BrowseComp, CharXiv-R, DeepSearchQA, DeepSWE 1.1, FrontierSWE, MCP Atlas, Toolathlon).
Kimi K3 shows notably better performance in the majority of benchmarks.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Opus 4.8 ($5.00/1M tokens) is 1.7x more expensive than Kimi K3 ($3.00/1M tokens).
For output processing, Claude Opus 4.8 ($25.00/1M tokens) is 1.7x more expensive than Kimi K3 ($15.00/1M 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
Documented input modalities across available providers
Both Claude Opus 4.8 and Kimi K3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Opus 4.8
Kimi K3
License
Usage and distribution terms
Claude Opus 4.8 is licensed under a proprietary license, while Kimi K3 uses Kimi K3 License.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
Kimi K3 License
Open weights
Release Timeline
When each model was launched
Claude Opus 4.8 was released on 2026-05-28, while Kimi K3 was released on 2026-07-16.
Kimi K3 is 2 months newer than Claude Opus 4.8.
May 28, 2026
3 months ago
Jul 16, 2026
1 months ago
1mo newerKnowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Claude Opus 4.8 is available from Anthropic, Vertex AI. Kimi K3 is available from Fireworks, Moonshot AI, Novita, Together.
Claude Opus 4.8
Kimi K3
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Opus 4.8 and Kimi K3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Opus 4.8 vs Kimi K3.