just4o.chat logojust4o.chatBeta
Back to features

Feature

Multiple model providers

Pick the model. It actually stays the model.

One place, multiple providers

Choose from OpenAI (GPT‑4o, GPT‑4.1, GPT‑5, o‑series), Anthropic (Claude), Google (Gemini), xAI (Grok), and Echo—right from the composer.

Your choice applies for the whole chat. No hidden routing, no surprise downgrades, no “we switched you to something else.” You pick; we stick to it.

Providers and model families

BasePremiumPremium +

ChatGPT

gpt-4o series

  • GPT-4o latest
  • GPT-4o · May 2024
  • GPT-4o · Aug. 2024
  • GPT-4o · Nov. 2024
  • GPT-4o
  • GPT-4o mini

gpt-5.1 series

  • GPT-5.1

gpt-5 series

  • GPT-5
  • GPT-5 codex
  • GPT-5 chat latest
  • GPT-5 mini
  • GPT-5 nano

gpt-4.1 series

  • GPT-4.1
  • GPT-4.1 mini
  • GPT-4.1 nano

o-series

  • o3
  • o4 mini
  • o3 mini

Claude

Claude

  • Claude Opus 4.5
  • Claude Sonnet 4.5
  • Claude Haiku 4.5

Gemini

Gemini 2.5 Series

  • Gemini 2.5 Pro
  • Gemini 2.5 Flash
  • Gemini 2.5 Flash-Lite

Gemini 3 Series

  • Gemini 3 Pro Preview
  • Gemini 3 Flash Preview

Grok

grok-code

  • Grok Code Fast 1

grok-4

  • Grok-4 Fast Reasoning
  • Grok-4 Fast Non-Reasoning

grok-4.1

  • Grok-4.1 Fast Reasoning
  • Grok-4.1 Fast Non-Reasoning

grok-3

  • Grok-3
  • Grok-3 Mini

just4o.chat

just4o.chat model

  • Echo

Transparent access and cost

Premium badges and cost hints show what each model uses before you send. New chats inherit your last selection so your workflow stays consistent.

Access varies by tier: Explorer gets base models, Builder unlocks Premium, Studio and Aurora unlock Premium+.

We pass through provider pricing and link to rate cards where relevant so cost‑per‑message math is clear.