Model Comparison

Claude Opus 5 vs GPT OSS 120BWhich is better in 2026?

Claude Opus 5 significantly outperforms across most benchmarks. GPT OSS 120B is 55.6x cheaper per token.

Verdict: Claude Opus 5 vs GPT OSS 120B — which is better?

Claude Opus 5 (by Anthropic) and GPT OSS 120B (by OpenAI) 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 5 outperforms in 1 benchmarks (Humanity's Last Exam), while GPT OSS 120B is better at 0 benchmarks. Claude Opus 5 significantly outperforms across most benchmarks.

On price, GPT OSS 120B is roughly 55.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Claude Opus 5 also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Claude Opus 5 if…

  • you want the strongest raw capability — it leads on 1 of 1 shared benchmarks
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Jul 2026

Choose GPT OSS 120B if…

  • cost matters — it's about 55.6x cheaper per token
  • you need open weights you can self-host or fine-tune

Performance Benchmarks

Comparative analysis across standard metrics

1 benchmarks

Claude Opus 5 outperforms in 1 benchmarks (Humanity's Last Exam), while GPT OSS 120B is better at 0 benchmarks.

Claude Opus 5 significantly outperforms across most benchmarks.

Sat Jul 25 2026 • llm-stats.com

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

GPT OSS 120B costs less

For input processing, Claude Opus 5 ($5.00/1M tokens) is 55.6x more expensive than GPT OSS 120B ($0.09/1M tokens).

For output processing, Claude Opus 5 ($25.00/1M tokens) is 55.6x more expensive than GPT OSS 120B ($0.45/1M tokens).

In conclusion, Claude Opus 5 is more expensive than GPT OSS 120B.*

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

Lowest available price from all providers
Sat Jul 25 2026 • llm-stats.com
Anthropic
Claude Opus 5
Input tokens$5.00
Output tokens$25.00
Best providerAnthropic
OpenAI
GPT OSS 120B
Input tokens$0.09
Output tokens$0.45
Best providerDeepinfra
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Claude Opus 5 accepts 1,000,000 input tokens compared to GPT OSS 120B's 131,072 tokens. GPT OSS 120B can generate longer responses up to 131,072 tokens, while Claude Opus 5 is limited to 128,000 tokens.

Anthropic
Claude Opus 5
Input1,000,000 tokens
Output128,000 tokens
OpenAI
GPT OSS 120B
Input131,072 tokens
Output131,072 tokens
Sat Jul 25 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Claude Opus 5 supports multimodal inputs, whereas GPT OSS 120B does not.

Claude Opus 5 can handle both text and other forms of data like images, making it suitable for multimodal applications.

Claude Opus 5

Text
Images
Audio
Video

GPT OSS 120B

Text
Images
Audio
Video

License

Usage and distribution terms

Claude Opus 5 is licensed under a proprietary license, while GPT OSS 120B uses Apache 2.0.

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

Claude Opus 5

Proprietary

Closed source

GPT OSS 120B

Apache 2.0

Open weights

Release Timeline

When each model was launched

Claude Opus 5 was released on 2026-07-24, while GPT OSS 120B was released on 2025-08-05.

Claude Opus 5 is 12 months newer than GPT OSS 120B.

Claude Opus 5

Jul 24, 2026

1 days ago

11mo newer
GPT OSS 120B

Aug 5, 2025

11 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

Provider Availability

Claude Opus 5 is available from Anthropic. GPT OSS 120B is available from DeepInfra, Novita, OpenAI, Fireworks, Groq.

Claude Opus 5

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

GPT OSS 120B

deepinfra logo
Deepinfra
Input Price:Input: $0.09/1MOutput Price:Output: $0.45/1M
novita logo
Novita
Input Price:Input: $0.10/1MOutput Price:Output: $0.50/1M
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
groq logo
Groq
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→

Key Takeaways

Anthropic
Larger context window (1,000,000 tokens)
Supports multimodal inputs
Higher Humanity's Last Exam score (64.7% vs 14.9%)
OpenAI
Less expensive input tokens
Less expensive output tokens
Has open weights

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Claude Opus 5 and GPT OSS 120B side-by-side, then vote on the output you prefer.

Claude Opus 5
✓ Preferred
GPT OSS 120B
Open in Playground
AI Model Comparison Table
Feature
Anthropic
Claude Opus 5
OpenAI
GPT OSS 120B

FAQ

Common questions about Claude Opus 5 vs GPT OSS 120B.

Which is better, Claude Opus 5 or GPT OSS 120B?

Claude Opus 5 significantly outperforms across most benchmarks. Claude Opus 5 is made by Anthropic and GPT OSS 120B is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Claude Opus 5 compare to GPT OSS 120B in benchmarks?

Claude Opus 5 scores BrowseComp: 90.8%, BioMysteryBench: 90.1%, OSWorld 2.0: 70.6%, DeepSWE 1.1: 68.8%, Humanity's Last Exam: 64.7%. GPT OSS 120B scores MMLU: 90.0%, CodeForces: 82.1%, GPQA: 80.1%, TAU-bench Retail: 67.8%, HealthBench: 57.6%.

Is Claude Opus 5 cheaper than GPT OSS 120B?

GPT OSS 120B is 55.6x cheaper for input tokens. Claude Opus 5 costs $5.00/M input and $25.00/M output via anthropic. GPT OSS 120B costs $0.09/M input and $0.45/M output via deepinfra.

What are the context window sizes for Claude Opus 5 and GPT OSS 120B?

Claude Opus 5 supports 1.0M tokens and GPT OSS 120B 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 5 and GPT OSS 120B?

Key differences include context window (1.0M vs 131K), input pricing ($5.00 vs $0.09/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 5 and GPT OSS 120B?

Claude Opus 5 is developed by Anthropic and GPT OSS 120B is developed by OpenAI.

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