Head to head

GPT-4o vs Grok 4.5

GPT-4o (OpenAI) and Grok 4.5 (xAI) compared on intelligence, speed, context, and price — and which to choose. Both run on just4o.chat from one chat.

MetricGPT-4oGrok 4.5
Intelligence (AA index)11
Output speed (tokens/sec)196.6
Context window128K500K
Max output
Input price / 1M$2.5$2
Output price / 1M$10$6
Released2024-05-132026-07-08

Choose GPT-4o if you want…

  • A comparable all-rounder — they trade blows on the headline metrics.

Choose Grok 4.5 if you want…

  • Lower price ($3 / 1M blended)
  • Larger context window (500K)

GPT-4o

Speed is GPT-4o's defining trait. Where comparable models average 61 tokens per second, GPT-4o delivers nearly 200 — and its native audio pipeline hits 320ms response latency, making it the practical choice for voice interfaces and real-time chat. It also collapses text, image, and audio processing into a single unified model rather than routing across separate systems, which produces more coherent multimodal reasoning without the awkward handoffs. Users feel this difference acutely. When OpenAI tried to retire GPT-4o in early 2026, the backlash was fierce enough to reverse the decision — petitions, mass unsubscribe threats, and user surveys suggesting 95% found no adequate replacement. That kind of loyalty comes from how the model feels in practice: snappy, versatile, fluent across 50+ languages, and capable of web search that reasoning-focused models like o1 lack. The honest caveat: GPT-4o trades raw reasoning depth for speed. It scores below average on Artificial Analysis's Intelligence Index and struggles with complex multi-step logic. For hard reasoning or large-document tasks, newer models outclass it. For fast, general-purpose, multimodal work, few match it.

Full GPT-4o details →

FAQ

Which is better, GPT-4o or Grok 4.5?

Grok 4.5 leads on 2 of the headline metrics (lower price ($3 / 1m blended); larger context window (500k)), while GPT-4o wins on other factors. The right pick depends on your priorities.

Is GPT-4o or Grok 4.5 cheaper?

Grok 4.5 is cheaper at $3 per 1M tokens (blended), versus $4.38.

Can I use both GPT-4o and Grok 4.5?

Yes. Both are available on just4o.chat from a single chat — you can switch between them per message with no separate subscriptions.