AI Models · Open-Source vs Paid

Hermes 4 405B Open vs Gemini 3.1 Pro Preview Paid

Hermes 4 405B vs Gemini 3.1 Pro Preview 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 · olud.ai

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

Hermes 4 405BOpenNous Research
$1 /M input
$3 /M outputNo per-token fees if you self-host
TypeOpen-weight
Context window131K tokens
MultimodalNo
Self-hostYes
Gemini 3.1 Pro PreviewPaidGoogle
$2 /M input
$12 /M outputManaged API (no infra to run)
TypeProprietary
Context window1M tokens
MultimodalYes
Self-hostNo
Choose Hermes 4 405B 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 Gemini 3.1 Pro Preview if you want frontier capability through a managed API with zero infrastructure to run.

Hermes 4 405B vs Gemini 3.1 Pro Preview specs

SpecHermes 4 405BGemini 3.1 Pro PreviewWinner
MakerNous ResearchGoogle
TypeOpen-weightProprietaryHermes 4 405B
Context window131K tokens1M tokensGemini 3.1 Pro Preview
Input price$1/M · free self-host$2/MHermes 4 405B
Output price$3/M · free self-host$12/MHermes 4 405B
Vision / multimodalNoYesGemini 3.1 Pro Preview
Tool / function callingNoYesGemini 3.1 Pro Preview
Self-hostableYesNo (API only)Hermes 4 405B
LicenseOpen weightsProprietaryHermes 4 405B

Price gap & when to choose each

4.0×cheaper per output token

Hermes 4 405B is ~4.0× cheaper than Gemini 3.1 Pro Preview on output tokens ($3 vs $12 per M tokens).

Choose Hermes 4 405B if…
  • You want to self-host or run on your cloud
  • You prioritize data privacy & control
  • You want the lowest operating costs
  • You are building open or reproducible AI
Choose Gemini 3.1 Pro Preview if…
  • You want frontier performance through a managed API
  • You need the longer 1M context window
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityHermes 4 405BGemini 3.1 Pro Preview
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Hermes 4 405B vs Gemini 3.1 Pro Preview

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

Hermes 4 405B
Gemini 3.1 Pro Preview
Intelligence index
7.5
30.4
Math index
69.7
GPQA
72.7%
94.1%
MMLU-Pro
82.9%
Humanity's Last Exam
10.9%
47%
Long Context Reasoning
22.3%
82%
LiveCodeBench
68.6%
AIME 2025
69.7%
IFBench
32.7%
77.1%
τ²-Bench
22.2%
95.6%
Terminal-Bench Hard
11.4%
53.8%
Coding index
68.8
SciCode
58.7%
τ-Bench Banking
21.4%
Terminal-Bench
73.8%
Speed
43.4 tok/s
125.2 tok/s
Latency
0.74s
24.48s
Intelligence per $
5
6.8

Benchmark data by Artificial Analysis.

How Hermes 4 405B and Gemini 3.1 Pro Preview score

🏆 Best value & openness: Hermes 4 405B (3.9 vs 3.2 / 5)
CriterionHermes 4 405BGemini 3.1 Pro Preview
Cost-efficiency4.03.5
Context window3.55.0
Openness5.01.5
Self-hosting5.01.0
Multimodality2.05.0

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

Hermes 4 405B Open

Nous Research · Open-weight

Hermes 4 is a large-scale reasoning model built on Meta-Llama-3.1-405B and released by Nous Research. It introduces a hybrid reasoning mode, where the model can choose to deliberate internally with...

Gemini 3.1 Pro Preview Paid

Google · Proprietary

Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation.

Other models in these families

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

Other variants tracked
Gemini 3.1 Pro Preview (batch)Gemini 2.5 ProGemini 2.5 Pro (batch)Gemini 2.5 Pro Preview 05-06Gemini 3.1 Pro Preview Custom ToolsNano Banana Pro (Gemini 3 Pro Image Preview)

Frequently asked questions

Is Hermes 4 405B as good as Gemini 3.1 Pro Preview?

Hermes 4 405B is open-weight and competitive on many tasks, but Gemini 3.1 Pro Preview 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 Hermes 4 405B locally?

Yes. Hermes 4 405B has open weights, so you can self-host it on your own GPUs or run it via a low-cost API. Gemini 3.1 Pro Preview is API-only and cannot be self-hosted.

How much cheaper is Hermes 4 405B?

Hermes 4 405B costs $3/M output vs $12/M for Gemini 3.1 Pro Preview — roughly 4x cheaper via API, and free if you self-host.

Hermes 4 405B vs Gemini 3.1 Pro Preview — which should I pick in 2026?

Choose Hermes 4 405B 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 Gemini 3.1 Pro Preview if you want frontier capability through a managed API with zero infrastructure to run.

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