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Claude Mythos Preview vs Grok-4.1 Thinking

Claude Mythos Preview significantly outperforms across most benchmarks. Grok-4.1 Thinking is 8.3x cheaper per token.

Anthropic · xAI · Updated for 2026

Which is better?

Claude Mythos Preview outperforms in 2 benchmarks (CyBench, FigQA), while Grok-4.1 Thinking is better at 0 benchmarks. Claude Mythos Preview significantly outperforms across most benchmarks.

On price, Grok-4.1 Thinking is roughly 8.3x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Claude Mythos Preview

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks

Choose Grok-4.1 Thinking

  • cost matters — it's about 8.3x cheaper per token

At a glance

The differences that matter most.

Claude Mythos Preview
Anthropic
Grok-4.1 Thinking
xAI
Benchmark wins
2 of 2
0 of 2
Input price
$25.00 / M
$3.00 / M
Output price
$125.00 / M
$15.00 / M
Context window
—
256,000
Released
—
Nov 2025
License
Proprietary
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Mythos Preview outperforms in 2 benchmarks (CyBench, FigQA), while Grok-4.1 Thinking is better at 0 benchmarks.

Claude Mythos Preview significantly outperforms across most benchmarks.

Tue Aug 25 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Pricing Analysis

Price comparison per million tokens

Grok-4.1 Thinking costs less

For input processing, Claude Mythos Preview ($25.00/1M tokens) is 8.3x more expensive than Grok-4.1 Thinking ($3.00/1M tokens).

For output processing, Claude Mythos Preview ($125.00/1M tokens) is 8.3x more expensive than Grok-4.1 Thinking ($15.00/1M tokens).

In conclusion, Claude Mythos Preview is more expensive than Grok-4.1 Thinking.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Tue Aug 25 2026 • llm-stats.com
Anthropic
Claude Mythos Preview
Input tokens$25.00
Output tokens$125.00
Best providerAnthropic
xAI
Grok-4.1 Thinking
Input tokens$3.00
Output tokens$15.00
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Only Grok-4.1 Thinking specifies input context (256,000 tokens). Only Grok-4.1 Thinking specifies output context (8,000 tokens).

Anthropic
Claude Mythos Preview
Input- tokens
Output- tokens
xAI
Grok-4.1 Thinking
Input256,000 tokens
Output8,000 tokens
Tue Aug 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Mythos Preview and Grok-4.1 Thinking support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Claude Mythos Preview

Text
Images
Audio
Video

Grok-4.1 Thinking

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Claude Mythos Preview

Proprietary

Closed source

Grok-4.1 Thinking

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-4.1 Thinking was released on 2025-11-17, while Claude Mythos Preview's release date is not specified.

We can confirm Grok-4.1 Thinking's release timeline, but cannot make a direct age comparison without Claude Mythos Preview's release date.

Claude Mythos Preview

—

Grok-4.1 Thinking

Nov 17, 2025

9 months ago

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

Claude Mythos Preview is available from Anthropic. Grok-4.1 Thinking is available from xAI.

Claude Mythos Preview

anthropic logo
Anthropic
Input Price:Input: $25.00/1MOutput Price:Output: $125.00/1M

Grok-4.1 Thinking

xai logo
xAI
Input Price:Input: $3.00/1MOutput Price:Output: $15.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Mythos Preview and Grok-4.1 Thinking side-by-side, then vote on the output you prefer.

Claude Mythos Preview
✓ Preferred
Grok-4.1 Thinking
Open in Playground

FAQ

Common questions about Claude Mythos Preview vs Grok-4.1 Thinking.

Which is better, Claude Mythos Preview or Grok-4.1 Thinking?

Claude Mythos Preview significantly outperforms across most benchmarks. Claude Mythos Preview is made by Anthropic and Grok-4.1 Thinking is made by xAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Mythos Preview compare to Grok-4.1 Thinking in benchmarks?

Claude Mythos Preview scores CyBench: 100.0%, USAMO25: 97.6%, GPQA: 94.6%, SWE-Bench Verified: 93.9%, CharXiv-R: 93.2%. Grok-4.1 Thinking scores Creative Writing v3: 86.1%, WMDP: 84.0%, EQ-Bench: 79.3%, ProtocolQA: 79.0%, LMArena Text Leaderboard: 74.2%.

Is Claude Mythos Preview cheaper than Grok-4.1 Thinking?

Grok-4.1 Thinking is 8.3x cheaper for input tokens. Claude Mythos Preview costs $25.00/M input and $125.00/M output via anthropic. Grok-4.1 Thinking costs $3.00/M input and $15.00/M output via xai.

What are the context window sizes for Claude Mythos Preview and Grok-4.1 Thinking?

Claude Mythos Preview supports an unknown number of tokens and Grok-4.1 Thinking supports 256K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Claude Mythos Preview and Grok-4.1 Thinking?

Key differences include input pricing ($25.00 vs $3.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos Preview and Grok-4.1 Thinking?

Claude Mythos Preview is developed by Anthropic and Grok-4.1 Thinking is developed by xAI.

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