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Claude Opus 4.5 vs GPT OSS 120B High

Claude Opus 4.5 leads the LLM Stats Score 38.3 to 25.5. GPT OSS 120B High is 50.0x cheaper per token.

Anthropic · OpenAI · Updated for 2026

Which is better?

Claude Opus 4.5 leads the overall LLM Stats Score 38.3 to 25.5, ranking #63 overall.

In the 2 individual benchmarks reported for both models, Claude Opus 4.5 wins 2; this is a narrower head-to-head signal than the composite indexes.

On price, GPT OSS 120B High is roughly 50.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 4.5 also accepts a larger context window (200,000 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 4.5

  • overall performance matters — it scores 38.3 and ranks #63 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 2 of 2 exact shared results
  • you process long inputs — it offers a 200,000 token context window
  • you want the most recent training data — it shipped Nov 2025

Choose GPT OSS 120B High

  • cost matters — it's about 50.0x cheaper per token
  • you need open weights you can self-host or fine-tune

At a glance

The differences that matter most.

Core performance indexes
38.3
#63
25.5
#148
40.2
#50
25.6
#141
17.7
#66
2.9
#153
Cost, coverage & limits
Benchmark wins
2 of 2
0 of 2
Input price
$5.00 / M
$0.10 / M
Output price
$25.00 / M
$0.50 / M
Context window
200,000
131,072

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
Claude Opus 4.5
GPT OSS 120B High
32.1#59
24.1#116
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

11 reported for Claude Opus 4.5 · 7 for GPT OSS 120B High

2 shared

Claude Opus 4.5 outperforms in 2 benchmarks (GPQA, MMMLU), while GPT OSS 120B High is better at 0 benchmarks.

Claude Opus 4.5 significantly outperforms across most benchmarks.

Sun Sep 06 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Pricing Analysis

Price comparison per million tokens

GPT OSS 120B High costs less

For input processing, Claude Opus 4.5 ($5.00/1M tokens) is 50.0x more expensive than GPT OSS 120B High ($0.10/1M tokens).

For output processing, Claude Opus 4.5 ($25.00/1M tokens) is 50.0x more expensive than GPT OSS 120B High ($0.50/1M tokens).

In conclusion, Claude Opus 4.5 is more expensive than GPT OSS 120B High.*

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

Lowest available price from all providers
Sun Sep 06 2026 • llm-stats.com
Anthropic
Claude Opus 4.5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT OSS 120B High
Input tokens$0.10
Output tokens$0.50
Best providerOpenAI
Notice missing or incorrect data?Start an Issue

Context Window

Maximum input and output token capacity

Claude Opus 4.5 accepts 200,000 input tokens compared to GPT OSS 120B High's 131,072 tokens. GPT OSS 120B High can generate longer responses up to 131,072 tokens, while Claude Opus 4.5 is limited to 64,000 tokens.

Anthropic
Claude Opus 4.5
Input200,000 tokens
Output64,000 tokens
OpenAI
GPT OSS 120B High
Input131,072 tokens
Output131,072 tokens
Sun Sep 06 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Claude Opus 4.5 supports multimodal inputs, whereas GPT OSS 120B High does not.

Claude Opus 4.5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 4.5

Text
Images
Audio
Video

GPT OSS 120B High

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 4.5 is licensed under a proprietary license, while GPT OSS 120B High uses Apache 2.0.

License differences may affect how you can use these models in commercial or open-source projects.

Claude Opus 4.5

Proprietary

Closed source

GPT OSS 120B High

Apache 2.0

Open weights

Release Timeline

When each model was launched

Claude Opus 4.5 was released on 2025-11-24, while GPT OSS 120B High was released on 2025-08-05.

Claude Opus 4.5 is 4 months newer than GPT OSS 120B High.

Claude Opus 4.5

Nov 24, 2025

9 months ago

3mo newer
GPT OSS 120B High

Aug 5, 2025

1.1 years ago

Knowledge Cutoff

When training data ends

Claude Opus 4.5 has a documented knowledge cutoff of 2025-03-31, while GPT OSS 120B High'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 GPT OSS 120B High's cutoff date.

Claude Opus 4.5

Mar 2025

GPT OSS 120B High

Provider Availability

Claude Opus 4.5 is available from Anthropic. GPT OSS 120B High is available from OpenAI, Fireworks.

Claude Opus 4.5

anthropic logo
Anthropic
Input Price:Input: $5.00/1MOutput Price:Output: $25.00/1M

GPT OSS 120B High

openai logo
OpenAI
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
fireworks logo
Fireworks
Input Price:Input: $0.15/1MOutput Price:Output: $0.60/1M
* 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 Opus 4.5 and GPT OSS 120B High side-by-side, then vote on the output you prefer.

Claude Opus 4.5
✓ Preferred
GPT OSS 120B High
Open in Playground

FAQ

Common questions about Claude Opus 4.5 vs GPT OSS 120B High.

Which is better, Claude Opus 4.5 or GPT OSS 120B High?

Claude Opus 4.5 leads the LLM Stats Score 38.3 to 25.5. Claude Opus 4.5 is made by Anthropic and GPT OSS 120B High is made by OpenAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Claude Opus 4.5 compare to GPT OSS 120B High 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%. GPT OSS 120B High scores AIME 2025: 92.5%, MMMLU: 83.8%, LiveCodeBench v6: 81.9%, GPQA: 80.9%, MMLU-Pro: 80.7%.

Is Claude Opus 4.5 cheaper than GPT OSS 120B High?

GPT OSS 120B High is 50.0x cheaper for input tokens. Claude Opus 4.5 costs $5.00/M input and $25.00/M output via anthropic. GPT OSS 120B High costs $0.10/M input and $0.50/M output via openai.

What are the context window sizes for Claude Opus 4.5 and GPT OSS 120B High?

Claude Opus 4.5 supports 200K tokens and GPT OSS 120B High supports 131K 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 4.5 and GPT OSS 120B High?

Key differences include LLM Stats Score (38.3 vs 25.5), context window (200K vs 131K), input pricing ($5.00 vs $0.10/M), multimodal support (yes vs no), licensing (Proprietary vs Apache 2.0). See the full comparison above for benchmark-by-benchmark results.

Who makes Claude Opus 4.5 and GPT OSS 120B High?

Claude Opus 4.5 is developed by Anthropic and GPT OSS 120B High is developed by OpenAI.