GPT-5.4 vs Grok-3
GPT-5.4 (2026) and Grok-3 (2026) are frontier-tier reasoning models from OpenAI and xAI. GPT-5.4 ships a not-yet-sourced context window, while Grok-3 ships a 1M-token context window. On MMLU PRO, GPT-5.4 leads by 7.6 pts. On pricing, Grok-3 costs $0.8/1M input tokens versus $2.5/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing.
Grok-3 is ~213% cheaper at $0.8/1M; pay for GPT-5.4 only for coding workflow support.
Specs
Pricing and availability
| GPT-5.4 | Grok-3 | |
|---|---|---|
| Input price | $2.5/1M tokens | $0.8/1M tokens |
| Output price | $15/1M tokens | $2.4/1M tokens |
| Providers |
Capabilities
| GPT-5.4 | Grok-3 | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
| Benchmark | GPT-5.4 | Grok-3 |
|---|---|---|
| MMLU PRO | 87.5 | 79.9 |
| Massive Multi-discipline Multimodal Understanding | 82.1 | 78.0 |
Deep dive
On shared benchmark coverage, MMLU PRO has GPT-5.4 at 87.5 and Grok-3 at 79.9, with GPT-5.4 ahead by 7.6 points; Massive Multi-discipline Multimodal Understanding has GPT-5.4 at 82.1 and Grok-3 at 78, with GPT-5.4 ahead by 4.1 points. The largest visible gap is 7.6 points on MMLU PRO, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.
The capability footprint differs most on vision: Grok-3 and code execution: GPT-5.4. Both models share multimodal input, reasoning mode, function calling, and tool use, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
For cost, GPT-5.4 lists $2.5/1M input and $15/1M output tokens, while Grok-3 lists $0.8/1M input and $2.4/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok-3 lower by about $4.97 per million blended tokens. Availability is 2 providers versus 3, so concentration risk also matters.
Choose GPT-5.4 when coding workflow support are central to the workload. Choose Grok-3 when vision-heavy evaluation, lower input-token cost, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which is cheaper, GPT-5.4 or Grok-3?
Grok-3 is cheaper on tracked token pricing. GPT-5.4 costs $2.5/1M input and $15/1M output tokens. Grok-3 costs $0.8/1M input and $2.4/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is GPT-5.4 or Grok-3 open source?
GPT-5.4 is listed under Proprietary. Grok-3 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, GPT-5.4 or Grok-3?
Grok-3 has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GPT-5.4 or Grok-3?
Both GPT-5.4 and Grok-3 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for reasoning mode, GPT-5.4 or Grok-3?
Both GPT-5.4 and Grok-3 expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run GPT-5.4 and Grok-3?
GPT-5.4 is available on OpenAI API and OpenRouter. Grok-3 is available on OpenRouter, xAI Console, and Chutes AI. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.