Key Takeaways
GPT-4o wins:
- Supports vision
- Supports tool calls
GPT-OSS-20b wins:
- Cheaper input tokens
- Cheaper output tokens
- Larger context window
- Faster response time
- Higher intelligence benchmark
- Better at coding
- Better at math
Price Advantage
GPT-OSS-20b
Benchmark Advantage
GPT-OSS-20b
Context Window
GPT-OSS-20b
Speed
GPT-OSS-20b
Pricing Comparison
Price Comparison
| Metric | GPT-4o | GPT-OSS-20b | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $2.50 | $0.02 | GPT-OSS-20b |
| Output (per 1M tokens) | $10.00 | $0.10 | GPT-OSS-20b |
| Cache Read (per 1M) | $1250000.00 | N/A | GPT-4o |
Using a 3:1 input/output ratio, GPT-OSS-20b is 99% cheaper overall.
GPT-4o Providers
OpenAI $2.50 (Cheapest)
Vercel $2.50 (Cheapest)
OpenRouter $2.50 (Cheapest)
Azure $2.50 (Cheapest)
GPT-OSS-20b Providers
GMICloud $0.02 (Cheapest)
DeepInfra $0.03
Parasail $0.04
Phala $0.04
SiliconFlow $0.04
Benchmark Comparison
8
Benchmarks Compared
0
GPT-4o Wins
3
GPT-OSS-20b Wins
Benchmark Scores
| Benchmark | GPT-4o | GPT-OSS-20b | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 15.6 | 24.7 | |
Coding Index Code generation & understanding | - | 18.1 | - |
Math Index Mathematical reasoning | - | 89.3 | - |
MMLU Pro Academic knowledge | - | 74.8 | - |
GPQA Graduate-level science | 52.1 | 68.8 | |
LiveCodeBench Competitive programming | 31.7 | 77.7 | |
Aider Real-world code editing | 74.4 | - | - |
AIME Competition math | 11.7 | - | - |
GPT-OSS-20b significantly outperforms in coding benchmarks.
Cost vs Quality
X-axis:
Y-axis:
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Other models
Context & Performance
Context Window
GPT-4o
128,000
tokens
Max output: 16,384 tokens
GPT-OSS-20b
131,072
tokens
Max output: 131,072 tokens
GPT-OSS-20b has a 2% larger context window.
Speed Performance
| Metric | GPT-4o | GPT-OSS-20b | Winner |
|---|---|---|---|
| Tokens/second | 77.3 tok/s | 309.0 tok/s | |
| Time to First Token | 0.51s | 0.51s | - |
GPT-OSS-20b responds 300% faster on average.
Capabilities
Feature Comparison
| Feature | GPT-4o | GPT-OSS-20b |
|---|---|---|
| Vision (Image Input) | ||
| Tool/Function Calls | ||
| Reasoning Mode | ||
| Audio Input | ||
| Audio Output | ||
| PDF Input | ||
| Prompt Caching | ||
| Web Search |
License & Release
| Property | GPT-4o | GPT-OSS-20b |
|---|---|---|
| License | Proprietary | Open Source |
| Author | OpenAI | OpenAI |
| Released | May 2024 | Aug 2025 |
GPT-4o Modalities
Input
textimagefile
Output
text
GPT-OSS-20b Modalities
Input
text
Output
text