Key Takeaways
GPT-4o-mini 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-mini | GPT-OSS-20b | Winner |
|---|---|---|---|
| Input (per 1M tokens) | $0.15 | $0.03 | GPT-OSS-20b |
| Output (per 1M tokens) | $0.60 | $0.14 | GPT-OSS-20b |
| Cache Read (per 1M) | $0.07 | N/A | GPT-4o-mini |
Using a 3:1 input/output ratio, GPT-OSS-20b is 78% cheaper overall.
GPT-4o-mini Providers
OpenAI $0.15 (Cheapest)
Vercel $0.15 (Cheapest)
Azure $0.15 (Cheapest)
GPT-OSS-20b Providers
DeepInfra $0.03 (Cheapest)
Parasail $0.04
Novita $0.04
NCompass $0.04
Clarifai $0.04
Benchmark Comparison
8
Benchmarks Compared
0
GPT-4o-mini Wins
5
GPT-OSS-20b Wins
Benchmark Scores
| Benchmark | GPT-4o-mini | GPT-OSS-20b | Winner |
|---|---|---|---|
Intelligence Index Overall intelligence score | 12.6 | 24.5 | |
Coding Index Code generation & understanding | - | 18.5 | - |
Math Index Mathematical reasoning | 14.7 | 89.3 | |
MMLU Pro Academic knowledge | 64.8 | 74.8 | |
GPQA Graduate-level science | 42.6 | 68.8 | |
LiveCodeBench Competitive programming | 23.4 | 77.7 | |
Aider Real-world code editing | 55.6 | - | - |
AIME Competition math | 11.7 | - | - |
GPT-OSS-20b significantly outperforms in coding benchmarks.
Cost vs Quality
X-axis:
Y-axis:
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GPT-4o-mini
Other models
Context & Performance
Context Window
GPT-4o-mini
128,000
tokens
Max output: 16,384 tokens
GPT-OSS-20b
131,072
tokens
GPT-OSS-20b has a 2% larger context window.
Speed Performance
| Metric | GPT-4o-mini | GPT-OSS-20b | Winner |
|---|---|---|---|
| Tokens/second | 58.0 tok/s | 321.8 tok/s | |
| Time to First Token | 0.54s | 0.45s |
GPT-OSS-20b responds 455% faster on average.
Capabilities
Feature Comparison
| Feature | GPT-4o-mini | 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-mini | GPT-OSS-20b |
|---|---|---|
| License | Proprietary | Open Source |
| Author | OpenAI | OpenAI |
| Released | Jul 2024 | Aug 2025 |
GPT-4o-mini Modalities
Input
textimagefile
Output
text
GPT-OSS-20b Modalities
Input
text
Output
text