AI model comparison
Phi 4 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.
Microsoft
Phi 4
[Microsoft Research](/microsoft) Phi-4 is designed to perform well in complex reasoning tasks and can operate efficiently in situations with limited memory or where quick responses are needed.
- Input / 1M
- $0.07
- Output / 1M
- $0.14
- Context
- 16K
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
Llama 3.1 8B Instruct
1.5x cheaper for a typical chat
Higher intelligence score
Llama 3.1 8B Instruct
6.9 vs 5.9 on Artificial Analysis
Larger context window
Llama 3.1 8B Instruct
131K vs 16K tokens
Newer release
Phi 4
Released January 10, 2025
Benchmarks
Benchmark scores
Independent scores from Artificial Analysis. Higher is better.
Intelligence index
Coding index
Agentic index
Pricing
Phi 4 vs Llama 3.1 8B Instruct API pricing
Per-token API rates. Cheaper option highlighted.
| Metric | ||
|---|---|---|
| Input tokensPer 1M tokens | $0.07 | $0.05 |
| Output tokensPer 1M tokens | $0.14 | $0.08 |
| Cached input (read)Per 1M tokens | Not available | $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
Coding task
30K in, 4K out
Long document summary
150K in, 2K out
Specs
Context window and capabilities
How much each model can read, how much it can write, and what it accepts as input.
| Metric | ||
|---|---|---|
| Context window | 16K tokens | 131K tokens |
| Max output | 15K tokens | 118K tokens |
| Input types | Text | Text |
| Output types | Text | Text |
| Reasoning effort levels | Not available | Not available |
| Default reasoning effort | Not available | Not available |
| Release date | January 10, 2025 | July 23, 2024 |
Features
Supported features
API features available for each model.
| Metric | ||
|---|---|---|
| Tool calling | Not supported | Supported |
| Structured outputs | Supported | Supported |
| JSON mode | Supported | Supported |
| Reasoning | Not 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 gpt-oss-20b
- 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 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
Llama 3.1 8B Instruct is 1.5x cheaper for a typical chat. Llama 3.1 8B Instruct scores higher on the Artificial Analysis Intelligence Index (6.9 vs 5.9). Llama 3.1 8B Instruct has the larger context window (131K vs 16K tokens). 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 Phi 4 or Llama 3.1 8B Instruct cheaper?
Llama 3.1 8B Instruct is cheaper for a typical chat (2K input tokens and 500 output tokens). Llama 3.1 8B Instruct costs $0.05 per 1M input tokens and $0.08 per 1M output tokens, while Phi 4 costs $0.07 per 1M input tokens and $0.14 per 1M output tokens.
Which has a bigger context window, Phi 4 or Llama 3.1 8B Instruct?
Llama 3.1 8B Instruct supports up to 131K tokens of context, compared with 16K for Phi 4.
Is Phi 4 smarter than Llama 3.1 8B Instruct?
On the Artificial Analysis Intelligence Index, Phi 4 scores 5.9 and Llama 3.1 8B Instruct scores 6.9, putting Llama 3.1 8B Instruct ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.
Can I use Phi 4 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 Phi 4 and Llama 3.1 8B Instruct answer side by side and keep the better response.
Why choose? Ask both.
Send one prompt to Phi 4 and Llama 3.1 8B Instruct at the same time. Compare the answers side by side and keep the best one.