AI Models · Open-Source vs Paid

Llama 3.1 8B Instruct Open vs GPT-5 Nano Paid

Llama 3.1 8B Instruct vs GPT-5 Nano compared — price per token, context window, multimodality, openness and which to choose. Can the open-source model replace the paid one? Full 2026 breakdown.

Prices & specs refreshed from live data · OpenSourceAI.tech

Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.

Choose Llama 3.1 8B Instruct if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-5 Nano if you want frontier capability through a managed API with zero infrastructure to run.

Llama 3.1 8B Instruct vs GPT-5 Nano specs

SpecLlama 3.1 8B InstructGPT-5 Nano
MakerMetaOpenAI
TypeOpen-weightProprietary
Context window131K tokens400K tokens
Input price$0.05/M · free self-host$0.05/M
Output price$0.08/M · free self-host$0.4/M
Vision / multimodalNoYes
Tool / function callingYesYes
Self-hostableYesNo (API only)
LicenseLlama CommunityProprietary

Feature comparison

CapabilityLlama 3.1 8B InstructGPT-5 Nano
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Llama 3.1 8B Instruct vs GPT-5 Nano

Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).

Llama 3.1 8B Instruct
GPT-5 Nano
Intelligence index
19.9
Math index
83.7
GPQA
67.6%
MMLU-Pro
78%
Humanity's Last Exam
8.2%
Long Context Reasoning
41.7%
LiveCodeBench
78.9%
SciCode
36.6%
AIME 2025
83.7%
IFBench
67.6%
τ²-Bench
36.5%
Terminal-Bench Hard
12.1%
Speed
174.3 tok/s
Latency
88.73s
Intelligence per $
144.2

Benchmark data by Artificial Analysis.

How Llama 3.1 8B Instruct and GPT-5 Nano score

🏆 Best value & openness: Llama 3.1 8B Instruct (4.4 vs 3.4 / 5)
CriterionLlama 3.1 8B InstructGPT-5 Nano
Cost-efficiency5.05.0
Context window3.54.5
Openness5.01.5
Self-hosting5.01.0
Multimodality3.55.0

Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.

What each model is

Llama 3.1 8B Instruct Open

Meta · Open-weight

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. It has demonstrated strong performance compared to...

GPT-5 Nano Paid

OpenAI · Proprietary

GPT-5-Nano is the smallest and fastest variant in the GPT-5 system, optimized for developer tools, rapid interactions, and ultra-low latency environments. While limited in reasoning depth compared to its larger...

Other models in these families

These variants are tracked but not compared here — one page per family keeps the comparison readable.

Other variants tracked
Llama 4 MaverickLlama 3.3 70B InstructLlama 4 ScoutLlama 3.1 70B InstructLlama Guard 4 12BLlama 3.2 3B InstructLlama 3.2 1B InstructHermes 3 405B InstructHermes 3 70B InstructR1 Distill Llama 70BAion-RP 1.0 (8B)
Other variants tracked
GPT-5.4 Nano

Frequently asked questions

Is Llama 3.1 8B Instruct as good as GPT-5 Nano?

Llama 3.1 8B Instruct is open-weight and competitive on many tasks, but GPT-5 Nano may still lead on the hardest reasoning and agentic work. The gap keeps narrowing — benchmark both on your actual use case before deciding.

Can I run Llama 3.1 8B Instruct locally?

Yes. Llama 3.1 8B Instruct has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. GPT-5 Nano is API-only and cannot be self-hosted.

How much cheaper is Llama 3.1 8B Instruct?

Llama 3.1 8B Instruct costs $0.08/M output vs $0.4/M for GPT-5 Nano — roughly 5x cheaper via API, and free if you self-host.

Llama 3.1 8B Instruct vs GPT-5 Nano — which should I pick in 2026?

Choose Llama 3.1 8B Instruct if you want to self-host, keep your data private and skip per-token fees — it's open-weight and runs on your own hardware. Choose GPT-5 Nano if you want frontier capability through a managed API with zero infrastructure to run.

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