Head to head
GPT-5.4 vs Grok 4.3
GPT-5.4 (OpenAI) and Grok 4.3 (xAI) compared on intelligence, speed, context, and price — and which to choose. Both run on just4o.chat from one chat.
| Metric | GPT-5.4 | Grok 4.3 |
|---|---|---|
| Intelligence (AA index) | 57 ✓ | 53 |
| Output speed (tokens/sec) | 163.4 | 168.7 ✓ |
| Context window | 1.1M ✓ | 1M |
| Max output | — | 1M |
| Input price / 1M | $2.5 | $1.25 ✓ |
| Output price / 1M | $15 | $2.5 ✓ |
| Released | 2026-03 | 2026-04 |
Choose GPT-5.4 if you want…
- Higher intelligence (Artificial Analysis index 57)
- Larger context window (1.1M)
Choose Grok 4.3 if you want…
- Faster output (~168.7 tokens/sec)
- Lower price ($1.56 / 1M blended)
GPT-5.4
GPT-5.4 was built for the actual work that happens inside offices — financial modeling, legal analysis, complex codebases, and multi-step document workflows — rather than for chasing narrow benchmarks. That strategic shift shows in the numbers: it matched or outperformed human professionals in 83% of head-to-head comparisons, and developers have called its coding output "flawless," with some declaring it the definitive choice for complex software engineering work. Native computer-use capabilities let it operate browsers and desktop apps directly, and it scored above the human baseline on UI interaction tasks. The 1.05 million token context window handles large codebases and lengthy legal documents in a single pass, though you need to configure it explicitly — the default is 272K. Where GPT-5.4 falls short is nuance: it tends to interpret requests too literally, missing the intent behind ambiguous prompts in ways that Claude handles more naturally. Writing personality is another common frustration, with verbose follow-up suggestions that can feel mechanical. For structured professional tasks where thoroughness and tool integration matter more than prose feel, it is the strongest model in the GPT-5 line prior to the release of GPT-5.5.
Full GPT-5.4 details →Grok 4.3
Grok 4.3 made a deliberate trade: xAI stopped chasing frontier performance and built something more practical instead. The result is a model that earns its keep through native X/Twitter integration — pulling posts seconds old when news breaks — and a 1 million token context window that handles entire codebases or lengthy regulatory documents in a single pass. At $1.25 per million input tokens, it arrives 40-60% cheaper than its predecessor Grok-4, and users find real value in its DeepSearch mode, which combines live web data with X discussions in a way that rivals Perplexity for current-events research. Frontend developers report genuinely polished web UI output, moving past the "cheap AI demo" look. The honest trade-off: creative writers consistently find it too literal and verbose, and its 16-second time-to-first-token sits at the high end for reasoning models in this price range. If your work is anchored in real-time information or long-document analysis rather than narrative craft, Grok 4.3 offers a focused, cost-sensible tool.
Full Grok 4.3 details →FAQ
Which is better, GPT-5.4 or Grok 4.3?
GPT-5.4 leads on 2 of the headline metrics (higher intelligence (artificial analysis index 57); larger context window (1.1m)), while Grok 4.3 wins on faster output (~168.7 tokens/sec); lower price ($1.56 / 1m blended). The right pick depends on whether you prioritise capability, speed, or cost.
Is GPT-5.4 or Grok 4.3 cheaper?
Grok 4.3 is cheaper at $1.56 per 1M tokens (blended), versus $5.63.
Can I use both GPT-5.4 and Grok 4.3?
Yes. Both are available on just4o.chat from a single chat — you can switch between them per message with no separate subscriptions.