GPT-5.4 Pro vs gpt-oss-20b
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5.4 Pro and gpt-oss-20b.
GPT-5.4 Pro
GPT-5.4 Pro is OpenAI's most advanced model, building on GPT-5.4's unified architecture with enhanced reasoning capabilities for complex, high-stakes tasks. It features a 1M+ token context window (922K input, 128K...
gpt-oss-20b
gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license. It uses a Mixture-of-Experts (MoE) architecture with 3.6B active parameters per forward pass, optimized for...
Technical Specifications
| Specification | GPT-5.4 Pro | gpt-oss-20b |
|---|---|---|
| Provider | OpenAI | OpenAI |
| Context Window | 1,050,000 tokens | 131,072 tokens |
| Agent Suitability | N/A | N/A |
| Time to First Token (TTFT) | N/A | N/A |
| Deployment Model | managed api | managed api |
| Production Stability | beta | stable |
| API Available | Yes | Yes |
| Released Date | 2026-03-05 | 2025-08-05 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5.4 Pro
$30.00
gpt-oss-20b
$0.03
Output Price per Million Tokens
GPT-5.4 Pro
$180.00
gpt-oss-20b
$0.14
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5.4 Pro Quirks & Gotchas
No developer gotchas reported.
gpt-oss-20b Quirks & Gotchas
No developer gotchas reported.