Model Comparison → Compare

Phi-4 vs Llama 3.1 8B

Our verdict

Phi-4 (14B) beats Llama 3.1 8B on quality despite being slightly larger. If VRAM allows, Phi-4 is the better SLM.

Microsoft Phi-4 (14B, $0.07/M input) vs Meta Llama 3.1 8B ($0.05/M input). Phi-4 is 40% more expensive but 20-30% better on reasoning benchmarks. If VRAM allows both (14GB vs 5GB at Q4), Phi-4 is worth the premium. If VRAM is severely constrained (mobile / edge), Llama 3.1 8B is your ceiling.

Side-by-side pricing

Phi-4Llama 3.1 8B
ProviderMicrosoftMeta
Input price/1M$0.070$0.050
Output price/1M$0.14$0.080
Cache read/1M
Context window16K128K
Vision
Tool use
Prompt caching
Speed tierFastFast

Prices verified 2026-08-20. See changelog for history.

Winner by task

Reasoning quality
Phi-4
20-30% better on MMLU, MATH, HumanEval despite smaller apparent size
Cost
Llama 3.1 8B
$0.05 vs $0.07/M — 40% cheaper
VRAM efficiency
Llama 3.1 8B
5GB at Q4 vs 9GB at Q4 — fits lower-end hardware
On-device / edge deployment
Llama 3.1 8B
Better tooling and format support for mobile deployment

Calculate costs for each model

Phi-4 pricing →Llama 3.1 8B pricing →Calculate for your workload →

Frequently Asked Questions

What makes Phi-4 good for its size?

Microsoft trained Phi-4 on a curated synthetic dataset specifically designed to maximize reasoning quality. Unlike larger models trained on web-crawled data, Phi-4's training data was filtered for quality and educational value. This "textbook learning" approach gives it disproportionate reasoning ability relative to its 14B parameters.

Prices verified 2026-08-20. See methodology for calculation details.