GPT-4o vs gpt-oss-20b
API pricing, context window and capabilities for GPT-4o and gpt-oss-20b, side by side. Prices are the cheapest serving route per 1M tokens, verified against LiteLLM and OpenRouter.
Verdict
computed from the published numbersgpt-oss-20b wins on price and on intelligence. Benchmark data is unavailable for one or both models.
Price
gpt-oss-20b
Coding
Not called
Intelligence
gpt-oss-20b
Context window
Tied
Key takeaways
who wins on what, from the published numbersGPT-4o wins
- Supports audio
gpt-oss-20b wins
- Cheaper input ($2.50 vs $0.01 /1M)
- Cheaper output ($10.00 vs $0.07 /1M)
- Higher max output (16K vs 131K)
- More serving providers (6 vs 12)
- Has reasoning mode
- Has web search
Cheaper overall
gpt-oss-20b
$0.01 + $0.07 /1M
Larger context
Tied
More providers
gpt-oss-20b
12 providers
Pricing & specs
cheapest serving route · per 1M tokens| GPT-4o | gpt-oss-20b | |
|---|---|---|
| Input $/1M | $2.50 | $0.01 best |
| Output $/1M | $10.00 | $0.07 best |
| Context window | 131K | 131K |
| Max output | 16K | 131K best |
| Serving providers | 6 | 12 best |
| Released | 2024-05-13 | 2026-03-01 |
Benchmarks
Artificial Analysis indices, side by side| GPT-4o | gpt-oss-20b | |
|---|---|---|
| Intelligence | 11.2 | 14.9 best |
| Coding | Not available | 20.7 |
| GPQA Diamond | 54% | 69% best |
| Output speed | 99 t/s | 139 t/s best |
| Latency (TTFT) | 5.19s best | 5.83s |
Cost calculator
choose a serving route for each sideInput tokens / month
Output tokens / month
GPT-4o
via Azure
$23
gpt-oss-20b
via Darkbloom
$0.14
Capabilities
feature support, side by side| Feature | GPT-4o | gpt-oss-20b |
|---|---|---|
| Vision | ✓ | ✓ |
| Tool use | ✓ | ✓ |
| Reasoning | — | ✓ |
| Audio | ✓ | — |
| Prompt caching | ✓ | ✓ |
| Structured output | ✓ | ✓ |
| Web search | — | ✓ |
Related comparisons
Frequently asked questions
Which is cheaper, GPT-4o or gpt-oss-20b?
gpt-oss-20b is cheaper for input ($2.50 vs $0.01 per 1M tokens). gpt-oss-20b is cheaper for output ($10.00 vs $0.07 per 1M tokens).
What is the context window difference between GPT-4o and gpt-oss-20b?
Both GPT-4o and gpt-oss-20b have about a 131K-token context window.
How do GPT-4o and gpt-oss-20b compare on benchmarks?
On the tracked Artificial Analysis indices, gpt-oss-20b leads on intelligence.
Pricing verified against LiteLLM + OpenRouter + provider pages · refreshed daily
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