AI Models · Open-Source vs Paid

Hermes 4 405B Open vs AIAion 3.5 Mini Paid

Hermes 4 405B vs Aion 3.5 Mini 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
AIAion 3.5 MiniPaidAionLabs
$0.7 /M input
$1.4 /M outputManaged API (no infra to run)
TypeProprietary
Context window262K tokens
MultimodalNo
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 Aion 3.5 Mini if you want frontier capability through a managed API with zero infrastructure to run.

Hermes 4 405B vs Aion 3.5 Mini specs

SpecHermes 4 405BAion 3.5 MiniWinner
MakerNous ResearchAionLabs–
TypeOpen-weightProprietaryHermes 4 405B
Context window131K tokens262K tokensAIAion 3.5 Mini
Input price$1/M · free self-host$0.7/MAIAion 3.5 Mini
Output price$3/M · free self-host$1.4/MAIAion 3.5 Mini
Vision / multimodalNoNo–
Tool / function callingNoYesAIAion 3.5 Mini
Self-hostableYesNo (API only)Hermes 4 405B
LicenseOpen weightsProprietaryHermes 4 405B

Price gap & when to choose each

2.1×cheaper per output token

Aion 3.5 Mini is ~2.1× cheaper than Hermes 4 405B on output tokens ($1.4 vs $3 per M tokens).

Choose Hermes 4 405B if…
  • You want to self-host or run on your cloud
  • You prioritize data privacy & control
  • You are building open or reproducible AI
AIChoose Aion 3.5 Mini if…
  • You want frontier performance through a managed API
  • You need the longer 262K context window
  • You want the lower output price
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityHermes 4 405BAion 3.5 Mini
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✗✗
Tool / function calling✗✓
1M+ context window✗✗

Benchmarks: Hermes 4 405B vs Aion 3.5 Mini

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

Hermes 4 405B
Aion 3.5 Mini
Intelligence index
7.4
–
Math index
15.3
–
GPQA
53.6%
–
MMLU-Pro
72.9%
–
Humanity's Last Exam
4.2%
–
Long Context Reasoning
22%
–
LiveCodeBench
54.6%
–
AIME 2025
15.3%
–
IFBench
34.8%
–
τ²-Bench
26.6%
–
Terminal-Bench Hard
9.8%
–
Speed
41.3 tok/s
–
Latency
0.64s
–
Intelligence per $
4.9
–

Benchmark data by Artificial Analysis.

How Hermes 4 405B and Aion 3.5 Mini score

🏆 Best value & openness: Hermes 4 405B (3.9 vs 2.9 / 5)
CriterionHermes 4 405BAion 3.5 Mini
Cost-efficiency4.04.5
Context window3.54.0
Openness5.01.5
Self-hosting5.01.0
Multimodality2.03.5

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...

Aion 3.5 Mini Paid

AionLabs · Proprietary

Aion 3.5 Mini is a multi-model roleplaying and storytelling system from AionLabs, built on the GLM family of models. It is the smaller, lower-cost sibling of Aion 3.5 and uses...

Frequently asked questions

Is Hermes 4 405B as good as Aion 3.5 Mini?

Hermes 4 405B is open-weight and competitive on many tasks, but Aion 3.5 Mini 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. Aion 3.5 Mini is API-only and cannot be self-hosted.

Hermes 4 405B vs Aion 3.5 Mini — 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 Aion 3.5 Mini if you want frontier capability through a managed API with zero infrastructure to run.

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