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.
| Metric | GPT-4o | Grok 4.5 |
|---|---|---|
| Intelligence (AA index) | 11 | — |
| Output speed (tokens/sec) | 196.6 | — |
| Context window | 128K | 500K ✓ |
| Max output | — | — |
| Input price / 1M | $2.5 | $2 ✓ |
| Output price / 1M | $10 | $6 ✓ |
| Released | 2024-05-13 | 2026-07-08 |
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.