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Claude Mythos 5.1 vs Seed 2.1 Turbo

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to 43.2.

Anthropic · ByteDance · Updated for 2026

Which is better?

Claude Mythos 5.1 leads the overall LLM Stats Score 45.1 to 43.2, ranking #33 overall.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Claude Mythos 5.1

  • overall performance matters — it scores 45.1 and ranks #33 on LLM Stats
  • your work emphasizes coding and agents — it leads those capability indexes
  • you want the most recent training data — it shipped Sep 2026

Choose Seed 2.1 Turbo

  • you are already invested in the ByteDance ecosystem

At a glance

The differences that matter most.

Claude Mythos 5.1
Anthropic
Seed 2.1 Turbo
ByteDance
Core performance indexes
LLM Stats Score
45.1
#33
43.2
#42
Reasoning
44.2
#37
44.5
#34
Coding
37.9
#17
31.0
#46
Agents
34.6
#23
29.1
#39
Cost, coverage & limits
Benchmark wins
—
—
Input price
$10.00 / M
— / M
Output price
$50.00 / M
— / M
Context window
1,000,000
—

Individual benchmarks

1 reported for Claude Mythos 5.1 · 90 for Seed 2.1 Turbo

No common benchmarks found

Claude Mythos 5.1 and Seed 2.1 Turbodon'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

Context Window

Maximum input and output token capacity

Only Claude Mythos 5.1 specifies input context (1,000,000 tokens). Only Claude Mythos 5.1 specifies output context (128,000 tokens).

Anthropic
Claude Mythos 5.1
Input1,000,000 tokens
Output128,000 tokens
ByteDance
Seed 2.1 Turbo
Input- tokens
Output- tokens
Sun Sep 20 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Mythos 5.1 and Seed 2.1 Turbo support multimodal inputs.

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

Claude Mythos 5.1

Text
Images
Audio
Video

Seed 2.1 Turbo

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 5.1

Proprietary

Closed source

Seed 2.1 Turbo

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Mythos 5.1 was released on 2026-09-01, while Seed 2.1 Turbo was released on 2026-06-24.

Claude Mythos 5.1 is 2 months newer than Seed 2.1 Turbo.

Claude Mythos 5.1

Sep 1, 2026

2 weeks ago

2mo newer
Seed 2.1 Turbo

Jun 24, 2026

2 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

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Claude Mythos 5.1 and Seed 2.1 Turbo side-by-side, then vote on the output you prefer.

Claude Mythos 5.1
✓ Preferred
Seed 2.1 Turbo
Open in Playground

FAQ

Common questions about Claude Mythos 5.1 vs Seed 2.1 Turbo.

Which is better, Claude Mythos 5.1 or Seed 2.1 Turbo?

Claude Mythos 5.1 leads the LLM Stats Score 45.1 to 43.2. Claude Mythos 5.1 is made by Anthropic and Seed 2.1 Turbo is made by ByteDance. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Mythos 5.1 compare to Seed 2.1 Turbo in benchmarks?

Claude Mythos 5.1 scores Terminal-Bench 4.0: 60.9%. Seed 2.1 Turbo scores CharXiv-D: 94.6%, MathVision: 92.7%, MathVista: 90.5%, MathVerse: 89.2%, Video-MME: 89.0%.

What are the context window sizes for Claude Mythos 5.1 and Seed 2.1 Turbo?

Claude Mythos 5.1 supports 1.0M tokens and Seed 2.1 Turbo supports an unknown number of 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 5.1 and Seed 2.1 Turbo?

Key differences include LLM Stats Score (45.1 vs 43.2). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Mythos 5.1 and Seed 2.1 Turbo?

Claude Mythos 5.1 is developed by Anthropic and Seed 2.1 Turbo is developed by ByteDance.

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