Head to head

GPT-4o vs GPT-5.6 Sol

GPT-4o (OpenAI) and GPT-5.6 Sol (OpenAI) compared on intelligence, speed, context, and price — and which to choose. Both run on just4o.chat from one chat.

MetricGPT-4oGPT-5.6 Sol
Intelligence (AA index)11
Output speed (tokens/sec)196.6
Context window128K1.1M
Max output128K
Input price / 1M$2.5$5
Output price / 1M$10$30
Released2024-05-132026-07-09

Choose GPT-4o if you want…

  • Lower price ($4.38 / 1M blended)

Choose GPT-5.6 Sol if you want…

  • Larger context window (1.1M)

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 GPT-5.6 Sol?

GPT-4o leads on 1 of the headline metrics (lower price ($4.38 / 1m blended)), while GPT-5.6 Sol wins on larger context window (1.1m). The right pick depends on whether you prioritise capability, speed, or cost.

Is GPT-4o or GPT-5.6 Sol cheaper?

GPT-4o is cheaper at $4.38 per 1M tokens (blended), versus $11.25.

Can I use both GPT-4o and GPT-5.6 Sol?

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