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Claude Opus 5.5 vs Seed 2.0 Pro

Claude Opus 5.5 leads the LLM Stats Score 60.3 to 39.5. Seed 2.0 Pro is 7.1x cheaper per token.

Anthropic · ByteDance · Updated for 2026

Which is better?

Claude Opus 5.5 leads the overall LLM Stats Score 60.3 to 39.5, ranking #1 overall.

On price, Seed 2.0 Pro is roughly 7.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 5.5 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 Opus 5.5

  • overall performance matters — it scores 60.3 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • 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 Seed 2.0 Pro

  • cost matters — it's about 7.1x cheaper per token

At a glance

The differences that matter most.

Claude Opus 5.5
Anthropic
Seed 2.0 Pro
ByteDance
Core performance indexes
LLM Stats Score
60.3
#1
39.5
#63
Reasoning
58.4
#1
39.0
#64
Coding
51.4
#1
22.0
#91
Agents
45.7
#2
16.8
#85
Cost, coverage & limits
Benchmark wins
—
—
Input price
$4.00 / M
$0.50 / M
Output price
$20.00 / M
$3.00 / M
Context window
1,000,000
256,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 5.5
Seed 2.0 Pro
Math
42.7#4
32.2#64
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

31 reported for Claude Opus 5.5 · 6 for Seed 2.0 Pro

No common benchmarks found

Claude Opus 5.5 and Seed 2.0 Prodon'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

Seed 2.0 Pro costs less

For input processing, Claude Opus 5.5 ($4.00/1M tokens) is 8.0x more expensive than Seed 2.0 Pro ($0.50/1M tokens).

For output processing, Claude Opus 5.5 ($20.00/1M tokens) is 6.7x more expensive than Seed 2.0 Pro ($3.00/1M tokens).

In conclusion, Claude Opus 5.5 is more expensive than Seed 2.0 Pro.*

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

Lowest available price from all providers
Fri Oct 02 2026 • llm-stats.com
Anthropic
Claude Opus 5.5
Input tokens$4.00
Output tokens$20.00
Best providerAnthropic
ByteDance
Seed 2.0 Pro
Input tokens$0.50
Output tokens$3.00
Best providerDeepinfra
Notice missing or incorrect data?

Context Window

Maximum input and output token capacity

Claude Opus 5.5 accepts 1,000,000 input tokens compared to Seed 2.0 Pro's 256,000 tokens. Seed 2.0 Pro can generate longer responses up to 131,072 tokens, while Claude Opus 5.5 is limited to 128,000 tokens.

Anthropic
Claude Opus 5.5
Input1,000,000 tokens
Output128,000 tokens
ByteDance
Seed 2.0 Pro
Input256,000 tokens
Output131,072 tokens
Fri Oct 02 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both Claude Opus 5.5 and Seed 2.0 Pro support multimodal inputs.

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

Claude Opus 5.5

Text
Images
Audio
Video

Seed 2.0 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 5.5

Proprietary

Closed source

Seed 2.0 Pro

Proprietary

Closed source

Release Timeline

When each model was launched

Claude Opus 5.5 was released on 2026-09-22, while Seed 2.0 Pro was released on 2026-02-14.

Claude Opus 5.5 is 7 months newer than Seed 2.0 Pro.

Claude Opus 5.5

Sep 22, 2026

1 weeks ago

7mo newer
Seed 2.0 Pro

Feb 14, 2026

7 months ago

Knowledge Cutoff

When training data ends

Claude Opus 5.5 has a knowledge cutoff of 2026-06-01, while Seed 2.0 Pro has a cutoff of 2024-01-01.

Claude Opus 5.5 has more recent training data (up to 2026-06-01), making it potentially better informed about events through that date compared to Seed 2.0 Pro (2024-01-01).

Claude Opus 5.5

Jun 2026

2.4 yr newer
Seed 2.0 Pro

Jan 2024

Provider Availability

Claude Opus 5.5 is available from Anthropic. Seed 2.0 Pro is available from DeepInfra.

Claude Opus 5.5

anthropic logo
Anthropic
Input Price:Input: $4.00/1MOutput Price:Output: $20.00/1M

Seed 2.0 Pro

deepinfra logo
Deepinfra
Input Price:Input: $0.50/1MOutput Price:Output: $3.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?

Judge for yourself.

Run your own prompts against Claude Opus 5.5 and Seed 2.0 Pro side-by-side, then vote on the output you prefer.

Claude Opus 5.5
✓ Preferred
Seed 2.0 Pro
Open in Playground

FAQ

Common questions about Claude Opus 5.5 vs Seed 2.0 Pro.

Which is better, Claude Opus 5.5 or Seed 2.0 Pro?

Claude Opus 5.5 leads the LLM Stats Score 60.3 to 39.5. Claude Opus 5.5 is made by Anthropic and Seed 2.0 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 5.5 compare to Seed 2.0 Pro in benchmarks?

Claude Opus 5.5 scores BenchCAD (with Python tool): 96.2%, Global-MMLU: 94.3%, SWE-bench Multilingual: 93.9%, MILU: 93.1%, ArXivMath: 91.2%. Seed 2.0 Pro scores AIME 2025: 98.3%, AIME 2026: 94.2%, GPQA: 88.9%, LiveCodeBench v6: 87.8%, BrowseComp: 77.3%.

Is Claude Opus 5.5 cheaper than Seed 2.0 Pro?

Seed 2.0 Pro is 8.0x cheaper for input tokens. Claude Opus 5.5 costs $4.00/M input and $20.00/M output via anthropic. Seed 2.0 Pro costs $0.50/M input and $3.00/M output via deepinfra.

What are the context window sizes for Claude Opus 5.5 and Seed 2.0 Pro?

Claude Opus 5.5 supports 1.0M tokens and Seed 2.0 Pro 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 Opus 5.5 and Seed 2.0 Pro?

Key differences include LLM Stats Score (60.3 vs 39.5), context window (1.0M vs 256K), input pricing ($4.00 vs $0.50/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 5.5 and Seed 2.0 Pro?

Claude Opus 5.5 is developed by Anthropic and Seed 2.0 Pro is developed by ByteDance.

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