Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed
  1. Home
  2. /
  3. Compare
  4. /
  5. GPT-4o (Omni)vsLlama 3.1 405B
Updated Jul 2024

GPT-4o (Omni)vsLlama 3.1 405B

GPT-4o (Omni) is cheaper than Llama 3.1 405B at $2.5/M vs $2.7/M input tokens.

GPT-4o (Omni) and Llama 3.1 405B compared across 12 shared prompts
SpecGPT-4o (Omni)Llama 3.1 405B
Input price$2.5/M tokens$2.7/M tokens
Output price$10/M tokens$3.1/M tokens
Context window128K tokens128K tokens
ParametersNot disclosed405B
WeightsClosedOpen
Free API (OpenRouter)NoNo
ReleasedMay 2024Jul 2024
MMLU88.7%88.6%
Our Verdict
GPT-4o (Omni)
GPT-4o (Omni)
Llama 3.1 405B
Llama 3.1 405B

Not enough votes to call it. On the specs, nothing separates them.

Llama 3.1 405B costs 3.2x less per token.

Too close to call

Reviewing agent-written code?See a Brief PR report

API pricing

Cost per 1M tokens

GPT-4o (Omni)
Input
$2.50
1.1× cheaper
Output
$10.00
Llama 3.1 405B
Input
$2.70
Output
$3.10
3.2× cheaper

GPT-4o (Omni) wins input (1.1× cheaper)·Llama 3.1 405B wins output (3.2× cheaper)

Where to run it

2 hosts

GPT-4o (Omni)2 hosts
HostInOutContextUptime
Azure AI Foundry$2.50 in·$10.00 out·128k·99.8% upOpenAI$2.50 in·$10.00 out·128k·99.9% up
Llama 3.1 405B

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 23 Sep 2026.

Writing DNA

Style Comparison

Similarity
45%

GPT-4o (Omni) uses 734.5x more bold

GPT-4o (Omni)
Llama 3.1 405B
54%Vocabulary55%
18wSentence Length15w
0.72Hedging0.41
7.3Bold0.0
5.6Lists1.9
0.03Emoji0.03
1.40Headings0.00
0.26Transitions0.16
Based on 24 + 5 text responses
Research

What we learned reading every model

FAQ

Common questions

GPT-4o (Omni) is developed by OpenAI while Llama 3.1 405B is developed by Meta AI. GPT-4o (Omni) has a 128K token context window vs Llama 3.1 405B's 128K. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.

It depends on your use case. GPT-4o (Omni) and Llama 3.1 405B each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.

GPT-4o (Omni) costs $2.5/M input tokens and Llama 3.1 405B costs $2.7/M input tokens. GPT-4o (Omni) is $0.20/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

This page shows a side-by-side comparison of GPT-4o (Omni) and Llama 3.1 405B across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

Keep exploring

More comparisons

Against the newest arrivals

GPT-4o (Omni) logoDeepSeek V4 Flash Vision Exp logo
GPT-4o (Omni) vs DeepSeek V4 Flash Vision ExpLanded Sep 2026
Llama 3.1 405B logoSolar Pro 4 logo
Llama 3.1 405B vs Solar Pro 4Landed Sep 2026
GPT-4o (Omni) logoHy3 logo
GPT-4o (Omni) vs Hy3Landed Sep 2026
Llama 3.1 405B logoQwen3.7 Flash logo
Llama 3.1 405B vs Qwen3.7 FlashLanded Sep 2026
GPT-4o (Omni) logoLing 3.0 Flash logo
GPT-4o (Omni) vs Ling 3.0 FlashLanded Sep 2026
Llama 3.1 405B logoMuse Glimmer 30B logo
Llama 3.1 405B vs Muse Glimmer 30BLanded Sep 2026
GPT-4o (Omni) logoGLM 5.3 logo
GPT-4o (Omni) vs GLM 5.3Landed Sep 2026
Llama 3.1 405B logoTernary Bonsai 2 27B logo
Llama 3.1 405B vs Ternary Bonsai 2 27BLanded Sep 2026

Same lab, same size, long tail

GPT-4o (Omni) logoGPT-6 Astra Pro logo
GPT-4o (Omni) vs GPT-6 Astra ProVersion compare
GPT-4o (Omni) logoGPT-6 Astra logo
GPT-4o (Omni) vs GPT-6 AstraVersion compare
Llama 3.1 405B logoMuse Spark 1.3 logo
Llama 3.1 405B vs Muse Spark 1.3Same lab
Llama 3.1 405B logoMuse Spark 1.3 Contributor logo
Llama 3.1 405B vs Muse Spark 1.3 ContributorSame lab
GPT-4o (Omni) logoSolar Pro 3 logo
GPT-4o (Omni) vs Solar Pro 3New provider
GPT-4o (Omni) logoSolar Pro 4 logo
GPT-4o (Omni) vs Solar Pro 4New provider
GPT-4o (Omni) logoTernary Bonsai 2 27B logo
GPT-4o (Omni) vs Ternary Bonsai 2 27BNew provider
GPT-4o (Omni) logoTrinity Large Preview logo
GPT-4o (Omni) vs Trinity Large PreviewSame size

Model pages

GPT-4o (Omni) logo
GPT-4o (Omni)54 outputs, specs and price
Llama 3.1 405B logo
Llama 3.1 405B12 outputs, specs and price
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare Models
  • All Models
  • Image Comparison
  • Audio Comparison
  • Image Generation
  • Best AI For...
  • Arena
  • API Pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model Updates
  • Provider Status
  • AI Creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy Policy
  • Terms
  • RSS Feed