AI Models · Open-Source vs Paid

Hermes 4 405B Open vs GPT-6 Sol Pro (batch) Paid

Hermes 4 405B vs GPT-6 Sol Pro (batch) 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
GPT-6 Sol Pro (batch)PaidOpenAI
$1 /M input
$5 /M outputManaged API (no infra to run)
TypeProprietary
Context window1.1M 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 GPT-6 Sol Pro (batch) if you want frontier capability through a managed API with zero infrastructure to run.

Hermes 4 405B vs GPT-6 Sol Pro (batch) specs

SpecHermes 4 405BGPT-6 Sol Pro (batch)Winner
MakerNous ResearchOpenAI–
TypeOpen-weightProprietaryHermes 4 405B
Context window131K tokens1.1M tokensGPT-6 Sol Pro (batch)
Input price$1/M · free self-host$1/M= Tie
Output price$3/M · free self-host$5/MHermes 4 405B
Vision / multimodalNoYesGPT-6 Sol Pro (batch)
Tool / function callingNoYesGPT-6 Sol Pro (batch)
Self-hostableYesNo (API only)Hermes 4 405B
LicenseOpen weightsProprietaryHermes 4 405B

Price gap & when to choose each

1.7×cheaper per output token

Hermes 4 405B is ~1.7× cheaper than GPT-6 Sol Pro (batch) on output tokens ($3 vs $5 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 GPT-6 Sol Pro (batch) if…
  • You want frontier performance through a managed API
  • You need the longer 1.1M context window
  • You value reliability & ecosystem
  • You don't want to manage infrastructure

Feature comparison

CapabilityHermes 4 405BGPT-6 Sol Pro (batch)
Open weights (downloadable)✓✗
Self-hostable✓✗
Runs fully offline✓✗
Vision / multimodal✗✓
Tool / function calling✗✓
1M+ context window✗✓

Benchmarks: Hermes 4 405B vs GPT-6 Sol Pro (batch)

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

Hermes 4 405B
GPT-6 Sol Pro (batch)
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 GPT-6 Sol Pro (batch) score

🏆 Best value & openness: Hermes 4 405B (3.9 vs 3.3 / 5)
CriterionHermes 4 405BGPT-6 Sol Pro (batch)
Cost-efficiency4.04.0
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...

GPT-6 Sol Pro (batch) Paid

OpenAI · Proprietary

GPT-6 Sol Pro is the same underlying model as [GPT-6 Sol](https://openrouter.ai/openai/gpt-6-sol), served with `reasoning.mode` set to `pro` for higher-quality responses on complex tasks. **Cost note:** pro mode spends far more...

Frequently asked questions

Is Hermes 4 405B as good as GPT-6 Sol Pro (batch)?

Hermes 4 405B is open-weight and competitive on many tasks, but GPT-6 Sol Pro (batch) 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. GPT-6 Sol Pro (batch) is API-only and cannot be self-hosted.

How much cheaper is Hermes 4 405B?

Hermes 4 405B costs $3/M output vs $5/M for GPT-6 Sol Pro (batch) — roughly 2x cheaper via API, and free if you self-host.

Hermes 4 405B vs GPT-6 Sol Pro (batch) — 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 GPT-6 Sol Pro (batch) if you want frontier capability through a managed API with zero infrastructure to run.

People also compare

Explore more open-source AI

Browse the full open-source model leaderboard, thousands of tools and live benchmarks — all in one place.

Open the leaderboard →