Claude Opus 4.5 vs gpt-oss-120b (Comparative Analysis)
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Comparative Analysis: Claude Opus 4.5 vs. gpt-oss-120b
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Overview
gpt-oss-120b was released 3 months before Claude Opus 4.5.
 Claude Opus 4.5 |  gpt-oss-120b | |
|---|---|---|
Model Provider The organization behind this AI's development | Anthropic | OpenAI |
Input Context Window Maximum input tokens this model can process at once | 200K tokens | 131.1K tokens |
Output Token Limit Maximum output tokens this model can generate at once | 64K tokens | 131.1K tokens |
Release Date When this model first became publicly available | November 24, 2025 8 months ago November 24th, 2025 | August 5, 2025 11 months ago August 5th, 2025 |
Knowledge Cutoff Latest training-data date reported by the provider | Not reported | June 30, 2024 |
Capabilities & Features
Compare supported features, modalities, and advanced capabilities
Claude Opus 4.5 | gpt-oss-120b | |
|---|---|---|
Input Types Supported input formats | 📁File🖼️Image📝Text | 📝Text |
Reasoning Controls Defaults and configurable reasoning effort | Optional | Always enabledEffort: High, Medium, LowDefault: Medium |
Output Types Supported output formats | 📝Text | 📝Text |
Tokenizer Text encoding system | Claude | GPT |
Key Features Advanced capabilities | ✓Function Calling✓Structured Output✓Reasoning Mode✓Content Moderation | ✓Function Calling✓Structured Output✓Reasoning ModeContent Moderation |
Open Source Model availability | Proprietary | Available on HuggingFace → |
Pricing
Claude Opus 4.5 is roughly 125.0x more expensive compared to gpt-oss-120b for input tokens and roughly 147.1x more expensive for output tokens.
| Claude Opus 4.5 | gpt-oss-120b | |
|---|---|---|
Input Token Cost Cost per million input tokens | $5.00 per million tokens | $0.04 per million tokens |
Output Token Cost Cost per million output tokens | $25.00 per million tokens | $0.17 per million tokens |
Web Search Cost Additional cost for each web search operation | $0.01 per search | Not specified |
Cache Read Cost Cost to reuse cached input tokens | $0.50 per million tokens | Not specified |
Cache Write Cost Cost to write input tokens to the cache | $6.25 per million tokens | Not specified |
1-Hour Cache Write Cost Cost to cache input tokens for one hour | $10.00 per million tokens | Not specified |
Benchmarks
Compare relevant benchmarks between Claude Opus 4.5 and gpt-oss-120b.
| Claude Opus 4.5 | gpt-oss-120b | |
|---|---|---|
Intelligence Index Overall model quality across independent evaluations | Benchmark not available. | 23.8 (Artificial Analysis index; higher is better) |
Coding Index Programming performance across independent evaluations | Benchmark not available. | 30.4 (Artificial Analysis index; higher is better) |
Agentic Index Ability to complete multi-step agentic tasks | Benchmark not available. | 13.2 (Artificial Analysis index; higher is better) |
Best Design Arena Score Highest human-preference Elo score across design arenas | 1,288 Elo (#20 in Game Dev (59.4% win rate)) | 1,052 Elo (#90 in Game Dev (40.6% win rate)) |
At a Glance
Quick overview of what makes Claude Opus 4.5 and gpt-oss-120b unique.
Claude Opus 4.5 by Anthropic understands both text and images, can use external tools and APIs, offers advanced reasoning, generates structured data. It can handle standard conversations with its 200K token context window. Premium pricing at $5.00/M input and $25.00/M output tokens. Includes built-in content moderation for safer outputs. Released November 24th, 2025.gpt-oss-120b by OpenAI can use external tools and APIs, offers advanced reasoning, generates structured data. It can handle standard conversations with its 131.1K token context window. Very affordable at $0.04/M input and $0.17/M output tokens. Released August 5th, 2025.Explore More Comparisons
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Compare gpt-oss-120b with:
🚀Programming
Best models for coding and development
🎨Creative & Roleplay
Models optimized for creative writing
📢Marketing
Content creation and marketing tasks
💻Technology
Technical analysis and explanations
🔬Science
Scientific research and analysis
🌐Translation
Multilingual translation tasks