AI Models · Open-Source vs Paid

Hermes 4 405B Open vs PEPerceptron Mk1.5 Paid

Hermes 4 405B vs Perceptron Mk1.5 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
PEPerceptron Mk1.5PaidPerceptron
$0.15 /M input
$1.5 /M outputManaged API (no infra to run)
TypeProprietary
Context window37K 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 Perceptron Mk1.5 if you want frontier capability through a managed API with zero infrastructure to run.

Hermes 4 405B vs Perceptron Mk1.5 specs

SpecHermes 4 405BPerceptron Mk1.5Winner
MakerNous ResearchPerceptron–
TypeOpen-weightProprietaryHermes 4 405B
Context window131K tokens37K tokensHermes 4 405B
Input price$1/M · free self-host$0.15/MPEPerceptron Mk1.5
Output price$3/M · free self-host$1.5/MPEPerceptron Mk1.5
Vision / multimodalNoYesPEPerceptron Mk1.5
Tool / function callingNoYesPEPerceptron Mk1.5
Self-hostableYesNo (API only)Hermes 4 405B
LicenseOpen weightsProprietaryHermes 4 405B

Price gap & when to choose each

2.0×cheaper per output token

Perceptron Mk1.5 is ~2.0× cheaper than Hermes 4 405B on output tokens ($1.5 vs $3 per M tokens).

Choose Hermes 4 405B if…
  • You want to self-host or run on your cloud
  • You need the longer 131K context window
  • You prioritize data privacy & control
  • You are building open or reproducible AI
PEChoose Perceptron Mk1.5 if…
  • You want frontier performance through a managed API
  • You want the lower output price
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityHermes 4 405BPerceptron Mk1.5
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✗✓
Tool / function calling✗✓
1M+ context window✗✗

Benchmarks: Hermes 4 405B vs Perceptron Mk1.5

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

Hermes 4 405B
Perceptron Mk1.5
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 Perceptron Mk1.5 score

🏆 Best value & openness: Hermes 4 405B (3.9 vs 2.9 / 5)
CriterionHermes 4 405BPerceptron Mk1.5
Cost-efficiency4.04.5
Context window3.52.5
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...

Perceptron Mk1.5 Paid

Perceptron · Proprietary

Perceptron Mk1.5 is Perceptron's embodied reasoning model for physical agents. It accepts text, image, video, and audio input, and answers with text plus optional structured annotations: points, boxes, polygons, tracks,...

Frequently asked questions

Is Hermes 4 405B as good as Perceptron Mk1.5?

Hermes 4 405B is open-weight and competitive on many tasks, but Perceptron Mk1.5 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. Perceptron Mk1.5 is API-only and cannot be self-hosted.

Hermes 4 405B vs Perceptron Mk1.5 — 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 Perceptron Mk1.5 if you want frontier capability through a managed API with zero infrastructure to run.

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