Nous

Hermes 4 405B

nousresearch/hermes-4-405b
Model weightsReleased Aug 26, 2025Open Weights
Thinkingopen weights

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...

Cost / 1M tokens

Medium usage

$1.00

input

$0.20

cached input

$3.00

output

Context Window

131K

Up to 118K max output

Modalities

text → text

Other tokenizer

Quickstart & API

nousresearch/hermes-4-405b
Open the model picker in ChatOSS Desktop (Code, Kanban, or Chat) and select or paste this model ID.

Best for & Strengths

Key Strengths

Open weightsExtended reasoning

Recommended Workloads in ChatOSS

  • Complex reasoning & debugging
  • Open-source AI workflows
Available in ChatOSS Code, Kanban Orchestrate, and Chat modes via Plus, Max, or BYOK.

Verified Evaluations

Benchmarks & Frontier Comparison

How Hermes 4 405B compares against leading open-weight and proprietary frontier models across independent agentic coding and reasoning suites.

View full Top 40 Leaderboard →
Benchmark (Metric)Hermes 4 405BDeepSeek V4.1 FlashGLM 5.3Kimi K3.1 ProClaude Opus 5.5
Agentic & Software Engineering
ChatOSS Agentic Coding Index (%)—63.2%58.3%65%74.1%
SWE-Bench Verified (%)—91.5%95.4%94.8%97%
DeepSWE v1.1 (Pass@1 %)—77%69%73.5%74.2%
Vibe Code Bench v1.1 (%)—87.7%78.1%88.4%90.3%
Terminal-Bench 4.0 (%)—42.3%42%46.2%65.2%
Code Migration (%)—45.6%44.2%52%66.7%
Intelligence & Token Economics
Artificial Analysis Intelligence Index (0–100)7.539.544.855.157.6
Input Price (/ 1M tokens)$1.00$0.15$1.40$2.00$4.00
Output Price (/ 1M tokens)$3.00$0.60$4.40$10.00$20.00

Artificial Analysis Intelligence Index

Artificial Analysis

7.5

Active Provider Endpoints (1)

Upstream inference providers serving Hermes 4 405B, with per-provider pricing, context limits, quantization, and 24-hour uptime.

ProviderInput / 1MOutput / 1MCache Read / 1MContextMax OutputQuantizationUptime (24h)
Nebiuscache
nebius/fp8
$1.00$3.00$0.20131K118Kfp8100.0%

Supported API Parameters

Parameters accepted by this model when called through ChatOSS or OpenRouter.

frequency_penaltyinclude_reasoninglogprobsmax_tokenspresence_penaltyreasoningrepetition_penaltyresponse_formatstructured_outputstemperaturetop_ktop_logprobstop_p

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