Claude Mythos 5.1 vs Kimi K3
Claude Mythos 5.1 and Kimi K3 are closely matched at 45.1 and 53.3 on the LLM Stats Score. Kimi K3 is 3.5x cheaper per token.
Anthropic · Moonshot AI · Updated for 2026
Which is better?
Claude Mythos 5.1 and Kimi K3 are closely matched on the overall LLM Stats Score at 45.1 and 53.3.
On price, Kimi K3 is roughly 3.5x 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 Mythos 5.1
- you want the most recent training data — it shipped Sep 2026
Choose Kimi K3
- cost matters — it's about 3.5x cheaper per token
- you process long inputs — it offers a 1,048,576 token context window
- you need open weights you can self-host or fine-tune
At a glance
The differences that matter most.
Individual benchmarks
1 reported for Claude Mythos 5.1 · 31 for Kimi K3
Claude Mythos 5.1 and Kimi K3don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, Claude Mythos 5.1 ($10.00/1M tokens) is 3.5x more expensive than Kimi K3 ($2.85/1M tokens).
For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 3.5x more expensive than Kimi K3 ($14.25/1M tokens).
In conclusion, Claude Mythos 5.1 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 Mythos 5.1's 1,000,000 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while Claude Mythos 5.1 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Both Claude Mythos 5.1 and Kimi K3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Claude Mythos 5.1
Kimi K3
License
Usage and distribution terms
Claude Mythos 5.1 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 Mythos 5.1 was released on 2026-09-01, while Kimi K3 was released on 2026-07-16.
Claude Mythos 5.1 is 2 months newer than Kimi K3.
Sep 1, 2026
1 weeks ago
1mo newerJul 16, 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
Claude Mythos 5.1 is available from Anthropic. Kimi K3 is available from DeepInfra, Fireworks, Moonshot AI, Novita, Together.
Claude Mythos 5.1
Kimi K3
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos 5.1 and Kimi K3 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos 5.1 vs Kimi K3.