AI Models · Open-Source vs Paid

Hermes 4 405B Open vs GPT-5.6 Terra Paid

Hermes 4 405B vs GPT-5.6 Terra 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.

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-5.6 Terra if you want frontier capability through a managed API with zero infrastructure to run.

Hermes 4 405B vs GPT-5.6 Terra specs

SpecHermes 4 405BGPT-5.6 Terra
MakerNous ResearchOpenAI
TypeOpen-weightProprietary
Context window131K tokens1.1M tokens
Input price$1/M · free self-host$1.25/M
Output price$3/M · free self-host$7.5/M
Vision / multimodalNoYes
Tool / function callingNoYes
Self-hostableYesNo (API only)
LicenseOpen weightsProprietary

Feature comparison

CapabilityHermes 4 405BGPT-5.6 Terra
Open weights (downloadable)
Self-hostable
Runs fully offline
Vision / multimodal
Tool / function calling
1M+ context window

Benchmarks: Hermes 4 405B vs GPT-5.6 Terra

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

Hermes 4 405B
GPT-5.6 Terra
Intelligence index
8.8
55
Math index
15.3
GPQA
53.6%
92.5%
MMLU-Pro
72.9%
Humanity's Last Exam
4.2%
41.8%
Long Context Reasoning
20%
74%
LiveCodeBench
54.6%
SciCode
34.6%
53.9%
AIME 2025
15.3%
IFBench
34.8%
71.2%
τ²-Bench
26.6%
86.3%
Terminal-Bench Hard
9.8%
57.6%
Coding index
76.7
τ-Bench Banking
31.8%
Terminal-Bench
88%
Speed
30.1 tok/s
136.5 tok/s
Latency
0.73s
106.97s
Intelligence per $
5.9
9.8

Benchmark data by Artificial Analysis.

How Hermes 4 405B and GPT-5.6 Terra score

🏆 Best value & openness: Hermes 4 405B (3.9 vs 3.3 / 5)
CriterionHermes 4 405BGPT-5.6 Terra
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-5.6 Terra Paid

OpenAI · Proprietary

GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...

Other models in these families

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

Other variants tracked
Hermes 4 70B

Frequently asked questions

Is Hermes 4 405B as good as GPT-5.6 Terra?

Hermes 4 405B is open-weight and competitive on many tasks, but GPT-5.6 Terra 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-5.6 Terra is API-only and cannot be self-hosted.

How much cheaper is Hermes 4 405B?

Hermes 4 405B costs $3/M output vs $7.5/M for GPT-5.6 Terra — roughly 3x cheaper via API, and free if you self-host.

Hermes 4 405B vs GPT-5.6 Terra — 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-5.6 Terra if you want frontier capability through a managed API with zero infrastructure to run.

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