AI model comparison
gpt-oss-20b vs Llama 3.1 8B Instruct
Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.
OpenAI
gpt-oss-20b
gpt-oss-20b is an open-weight 21B parameter model released by OpenAI under the Apache 2.0 license.
- Input / 1M
- $0.02
- Output / 1M
- $0.09
- Context
- 131K
Meta's latest class of model (Llama 3.1) launched with a variety of sizes & flavors. This 8B instruct-tuned version is fast and efficient.
- Input / 1M
- $0.05
- Output / 1M
- $0.08
- Context
- 131K
At a glance
Quick verdict
How the two models stack up on the things people ask about most.
Lower price
gpt-oss-20b
1.7x cheaper for a typical chat
Higher intelligence score
gpt-oss-20b
10 vs 6.9 on Artificial Analysis
Larger context window
Tie
131K vs 131K tokens
Newer release
gpt-oss-20b
Released August 5, 2025
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
gpt-oss-20b10Coding index
gpt-oss-20bNot availableAgentic index
gpt-oss-20bNot availablePricing
gpt-oss-20b vs Llama 3.1 8B Instruct API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | gpt-oss-20b | |
|---|---|---|
| Input tokensPer 1M tokens | $0.02 | $0.05 |
| Output tokensPer 1M tokens | $0.09 | $0.08 |
| Cached input (read)Per 1M tokens | $0.01 | $0.03 |
| Cache writePer 1M tokens | Not available | Not available |
What it costs in practice
Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.
Chat message
2K in, 500 out
gpt-oss-20b$0.08Coding task
30K in, 4K out
gpt-oss-20b$0.90$0.63 cachedLong document summary
150K in, 2K out
gpt-oss-20b$2.88$1.53 cachedSpecs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | gpt-oss-20b | |
|---|---|---|
| Context window | 131K tokens | 131K tokens |
| Max output | 33K tokens | 118K tokens |
| Input types | Text | Text |
| Output types | Text | Text |
| Reasoning effort levels | High, Medium, Low | Not available |
| Default reasoning effort | Medium | Not available |
| Release date | August 5, 2025 | July 23, 2024 |
Features
Supported features
API features available for each model.
| Metric | gpt-oss-20b | |
|---|---|---|
| Tool calling | Supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Supported | Not supported |
| Temperature | Supported | Supported |
| Stop sequences | Supported | Supported |
| Deterministic seed | Supported | Supported |
| Verbosity control | Not supported | Not supported |
Keep exploring
More on these models
Other head-to-heads, the full model page, and the alternatives list for each model.
- Llama 3.1 8B Instruct vs Mistral Nemo
- Llama 3.1 8B Instruct vs Llama 3.3 70B Instruct
- Llama 3.1 8B Instruct vs Nova Micro 1.0
- Llama 3.1 8B Instruct vs Mistral Small 3
- Llama 3.1 8B Instruct vs Llama 4 Scout
- Llama 3.1 8B Instruct vs Ministral 3 8B 2512
- Llama 3.1 8B Instruct vs Ministral 3 3B 2512
- Llama 3.1 8B Instruct vs Phi 4
- Llama 3.1 8B Instruct vs Granite 4.0 Micro
- Llama 3.1 8B Instruct vs Llama 3.1 70B Instruct
- Llama 3.1 8B Instruct vs Llama 3.2 3B Instruct
- Llama 3.1 8B Instruct vs Reka Flash 3
- Llama 3.1 8B Instruct vs Gemma 3 4B
- Llama 3.1 8B Instruct vs Llama 3.2 1B Instruct
Our take
gpt-oss-20b is 1.7x cheaper for a typical chat. gpt-oss-20b scores higher on the Artificial Analysis Intelligence Index (10 vs 6.9). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.
FAQ
Frequently asked questions
Is gpt-oss-20b or Llama 3.1 8B Instruct cheaper?
gpt-oss-20b is cheaper for a typical chat (2K input tokens and 500 output tokens). gpt-oss-20b costs $0.02 per 1M input tokens and $0.09 per 1M output tokens, while Llama 3.1 8B Instruct costs $0.05 per 1M input tokens and $0.08 per 1M output tokens.
Which has a bigger context window, gpt-oss-20b or Llama 3.1 8B Instruct?
gpt-oss-20b supports up to 131K tokens of context, compared with 131K for Llama 3.1 8B Instruct.
Is gpt-oss-20b smarter than Llama 3.1 8B Instruct?
On the Artificial Analysis Intelligence Index, gpt-oss-20b scores 10 and Llama 3.1 8B Instruct scores 6.9, putting gpt-oss-20b ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use gpt-oss-20b and Llama 3.1 8B Instruct at the same time?
Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see gpt-oss-20b and Llama 3.1 8B Instruct answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to gpt-oss-20b and Llama 3.1 8B Instruct at the same time. Compare the answers side by side and keep the best one.