Model Comparison

Claude Opus 4.5 vs Seed 2.1 TurboWhich is better in 2026?

Seed 2.1 Turbo significantly outperforms across most benchmarks.

Verdict: Claude Opus 4.5 vs Seed 2.1 Turbo — which is better?

Claude Opus 4.5 (by Anthropic) and Seed 2.1 Turbo (by ByteDance) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

Claude Opus 4.5 outperforms in 0 benchmarks, while Seed 2.1 Turbo is better at 2 benchmarks (MCP Atlas, OSWorld). Seed 2.1 Turbo significantly outperforms across most benchmarks.

Choose Claude Opus 4.5 if…

  • you want predictable pricing at $5.00/M input and $25.00/M output

Choose Seed 2.1 Turbo if…

  • you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
  • you want the most recent training data — it shipped Jun 2026
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Performance Benchmarks

Comparative analysis across standard metrics

2 benchmarks

Claude Opus 4.5 outperforms in 0 benchmarks, while Seed 2.1 Turbo is better at 2 benchmarks (MCP Atlas, OSWorld).

Seed 2.1 Turbo significantly outperforms across most benchmarks.

Thu Jun 25 2026 • llm-stats.com

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Claude Opus 4.5 specifies input context (200,000 tokens). Only Claude Opus 4.5 specifies output context (64,000 tokens).

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
ByteDance
Seed 2.1 Turbo
Input- tokens
Output- tokens
Thu Jun 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Claude Opus 4.5 and Seed 2.1 Turbo support multimodal inputs.

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

Claude Opus 4.5

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 Opus 4.5

Proprietary

Closed source

Seed 2.1 Turbo

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while Seed 2.1 Turbo was released on 2026-06-24.

Seed 2.1 Turbo is 7 months newer than Claude Opus 4.5.

Claude Opus 4.5

Nov 24, 2025

7 months ago

Seed 2.1 Turbo

Jun 24, 2026

1 days ago

7mo newer

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while Seed 2.1 Turbo's cutoff date is not specified.

We can confirm Claude Opus 4.5's training data extends to 2025-03-31, but cannot make a direct comparison without Seed 2.1 Turbo's cutoff date.

Claude Opus 4.5

Mar 2025

Seed 2.1 Turbo

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Outputs Comparison

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Key Takeaways

Anthropic
Larger context window (200,000 tokens)
ByteDance
Higher MCP Atlas score (80.3% vs 62.3%)
Higher OSWorld score (76.4% vs 66.3%)

Detailed Comparison

AI Model Comparison Table
Feature
Anthropic
Claude Opus 4.5
ByteDance
Seed 2.1 Turbo

FAQ

Common questions about Claude Opus 4.5 vs Seed 2.1 Turbo.

Which is better, Claude Opus 4.5 or Seed 2.1 Turbo?

Seed 2.1 Turbo significantly outperforms across most benchmarks. Claude Opus 4.5 is made by Anthropic and Seed 2.1 Turbo is made by ByteDance. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 4.5 compare to Seed 2.1 Turbo in benchmarks?

Claude Opus 4.5 scores Tau2 Telecom: 98.2%, MMMLU: 90.8%, Tau2 Retail: 88.9%, GPQA: 87.0%, SWE-Bench Verified: 80.9%. 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 Opus 4.5 and Seed 2.1 Turbo?

Claude Opus 4.5 supports 200K 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.

Who makes Claude Opus 4.5 and Seed 2.1 Turbo?

Claude Opus 4.5 is developed by Anthropic and Seed 2.1 Turbo is developed by ByteDance.

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