Claude Mythos 5.1 vs DeepSeek-R1
Comparing Claude Mythos 5.1 and DeepSeek-R1 across benchmarks, pricing, and capabilities.
Anthropic · DeepSeek · Updated for 2026
Which is better?
Claude Mythos 5.1 and DeepSeek-R1 trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, DeepSeek-R1 is roughly 20.8x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Claude Mythos 5.1 also accepts a larger context window (1,000,000 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 process long inputs — it offers a 1,000,000 token context window
- you want the most recent training data — it shipped Sep 2026
Choose DeepSeek-R1
- cost matters — it's about 20.8x cheaper per token
- 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 · 0 for DeepSeek-R1
Claude Mythos 5.1 and DeepSeek-R1don'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 18.2x more expensive than DeepSeek-R1 ($0.55/1M tokens).
For output processing, Claude Mythos 5.1 ($50.00/1M tokens) is 22.8x more expensive than DeepSeek-R1 ($2.19/1M tokens).
In conclusion, Claude Mythos 5.1 is more expensive than DeepSeek-R1.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Claude Mythos 5.1 accepts 1,000,000 input tokens compared to DeepSeek-R1's 131,072 tokens. DeepSeek-R1 can generate longer responses up to 131,072 tokens, while Claude Mythos 5.1 is limited to 128,000 tokens.
Input capabilities
Documented input modalities across available providers
Claude Mythos 5.1 supports multimodal inputs, whereas DeepSeek-R1 does not.
Claude Mythos 5.1 can handle both text and other forms of data like images, making it suitable for multimodal applications.
Claude Mythos 5.1
DeepSeek-R1
License
Usage and distribution terms
Claude Mythos 5.1 is licensed under a proprietary license, while DeepSeek-R1 uses MIT.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
MIT
Open weights
Release Timeline
When each model was launched
Claude Mythos 5.1 was released on 2026-09-01, while DeepSeek-R1 was released on 2025-01-20.
Claude Mythos 5.1 is 20 months newer than DeepSeek-R1.
Sep 1, 2026
1 weeks ago
1.6yr newerJan 20, 2025
1.6 years 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. DeepSeek-R1 is available from DeepSeek, DeepInfra, Together, Fireworks.
Claude Mythos 5.1
DeepSeek-R1
Outputs Comparison
Judge for yourself.
Run your own prompts against Claude Mythos 5.1 and DeepSeek-R1 side-by-side, then vote on the output you prefer.
FAQ
Common questions about Claude Mythos 5.1 vs DeepSeek-R1.