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Claude Opus 4.8 vs Seed 2.1 Pro

Claude Opus 4.8 leads the LLM Stats Score 51.1 to 46.4.

Anthropic · ByteDance · Updated for 2026

Which is better?

Claude Opus 4.8 leads the overall LLM Stats Score 51.1 to 46.4, ranking #13 overall.

In the 8 individual benchmarks reported for both models, Claude Opus 4.8 wins 5; this is a narrower head-to-head signal than the composite indexes.

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

Choose Claude Opus 4.8

  • overall performance matters — it scores 51.1 and ranks #13 on LLM Stats
  • your work emphasizes coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 5 of 8 exact shared results

Choose Seed 2.1 Pro

  • you want the most recent training data — it shipped Jun 2026

At a glance

The differences that matter most.

Claude Opus 4.8
Anthropic
Seed 2.1 Pro
ByteDance
Core performance indexes
LLM Stats Score
51.1
#13
46.4
#25
Reasoning
50.6
#12
47.2
#22
Coding
41.8
#9
33.7
#31
Agents
35.2
#17
31.3
#26
Cost, coverage & limits
Benchmark wins
5 of 8
3 of 8
Input price
$5.00 / M
— / M
Output price
$25.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

6 shared
Index
Claude Opus 4.8
Seed 2.1 Pro
Math
39.2#19
39.1#20
Vision
36.1#8
34.2#12
Tool use
30.4#16
26.4#27
Long context
20.6#25
28.8#5
Multimodal
35.6#9
37.4#4
1 more shared indexes
Finance
27.3#37
34.0#7
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

27 reported for Claude Opus 4.8 · 94 for Seed 2.1 Pro

8 shared

Claude Opus 4.8 outperforms in 5 benchmarks (CharXiv-R, CyberGym, Humanity's Last Exam, SWE-Bench Pro, Toolathlon), while Seed 2.1 Pro is better at 3 benchmarks (BrowseComp, MCP Atlas, OfficeQA Pro).

Claude Opus 4.8 shows notably better performance in the majority of benchmarks.

Sun Sep 06 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Claude Opus 4.8 specifies input context (1,000,000 tokens). Only Claude Opus 4.8 specifies output context (128,000 tokens).

Anthropic
Claude Opus 4.8
Input1,000,000 tokens
Output128,000 tokens
ByteDance
Seed 2.1 Pro
Input- tokens
Output- tokens
Sun Sep 06 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 4.8 and Seed 2.1 Pro support multimodal inputs.

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

Claude Opus 4.8

Text
Images
Audio
Video

Seed 2.1 Pro

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 4.8

Proprietary

Closed source

Seed 2.1 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 4.8 was released on 2026-05-28, while Seed 2.1 Pro was released on 2026-06-24.

Seed 2.1 Pro is 1 month newer than Claude Opus 4.8.

Claude Opus 4.8

May 28, 2026

3 months ago

Seed 2.1 Pro

Jun 24, 2026

2 months ago

3w newer

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 Opus 4.8 and Seed 2.1 Pro side-by-side, then vote on the output you prefer.

Claude Opus 4.8
✓ Preferred
Seed 2.1 Pro
Open in Playground

FAQ

Common questions about Claude Opus 4.8 vs Seed 2.1 Pro.

Which is better, Claude Opus 4.8 or Seed 2.1 Pro?

Claude Opus 4.8 leads the LLM Stats Score 51.1 to 46.4. Claude Opus 4.8 is made by Anthropic and Seed 2.1 Pro 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 Opus 4.8 compare to Seed 2.1 Pro in benchmarks?

Claude Opus 4.8 scores GPQA: 93.6%, DeepSearchQA: 93.1%, CharXiv-R: 89.9%, SWE-Bench Verified: 88.6%, ScreenSpot Pro: 87.9%. Seed 2.1 Pro scores CharXiv-D: 95.5%, MathVision: 94.5%, MathVista: 90.7%, MathVerse: 89.7%, Video-MME: 89.2%.

What are the context window sizes for Claude Opus 4.8 and Seed 2.1 Pro?

Claude Opus 4.8 supports 1.0M tokens and Seed 2.1 Pro 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 Opus 4.8 and Seed 2.1 Pro?

Key differences include LLM Stats Score (51.1 vs 46.4). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.8 and Seed 2.1 Pro?

Claude Opus 4.8 is developed by Anthropic and Seed 2.1 Pro is developed by ByteDance.

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