GPT-5.4 Nano vs Grok 4.3
GPT-5.4 Nano (2026) and Grok 4.3 (2026) are frontier reasoning models from OpenAI and xAI. GPT-5.4 Nano ships a 400K-token context window, while Grok 4.3 ships a 1M-token context window. On pricing, GPT-5.4 Nano costs $0.2/1M input tokens versus $1.25/1M 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.
GPT-5.4 Nano is ~525% cheaper at $0.2/1M; pay for Grok 4.3 only for reasoning depth.
Decision scorecard
Local evidence first| Signal | GPT-5.4 Nano | Grok 4.3 |
|---|---|---|
| Decision fit | Coding, RAG, and Agents | RAG, Agents, and Long context |
| Context window | 400K | 1M |
| Cheapest output | $1.25/1M tokens | $2.5/1M tokens |
| Provider routes | 2 tracked | 2 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- GPT-5.4 Nano has the lower cheapest tracked output price at $1.25/1M tokens.
- GPT-5.4 Nano uniquely exposes Code execution in local model data.
- Local decision data tags GPT-5.4 Nano for Coding, RAG, and Agents.
- Grok 4.3 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Grok 4.3 uniquely exposes Vision and Reasoning in local model data.
- Local decision data tags Grok 4.3 for RAG, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
GPT-5.4 Nano
$473
Cheapest tracked route: OpenAI API
Grok 4.3
$1,625
Cheapest tracked route: xAI Console
Estimated monthly gap: $1,153. Batch, cache, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4.3 is $1.25/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Check replacement coverage for Code execution before moving production traffic.
- Grok 4.3 adds Vision and Reasoning in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- GPT-5.4 Nano is $1.25/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision and Reasoning before moving production traffic.
- GPT-5.4 Nano adds Code execution in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-03-05 | 2026-05-05 |
| Context window | 400K | 1M |
| Parameters | — | ~0.5T |
| Architecture | decoder only | - |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-08 | - |
Pricing and availability
| Pricing attribute | GPT-5.4 Nano | Grok 4.3 |
|---|---|---|
| Input price | $0.2/1M tokens | $1.25/1M tokens |
| Output price | $1.25/1M tokens | $2.5/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.4 Nano | Grok 4.3 |
|---|---|---|
| Vision | No | Yes |
| Multimodal | Yes | Yes |
| Reasoning | No | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | Yes | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Grok 4.3, reasoning mode: Grok 4.3, and code execution: GPT-5.4 Nano. Both models share multimodal input, function calling, tool use, and structured outputs, 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 Nano lists $0.2/1M input and $1.25/1M output tokens, while Grok 4.3 lists $1.25/1M input and $2.5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts GPT-5.4 Nano lower by about $1.11 per million blended tokens. Availability is 2 providers versus 2, so concentration risk also matters.
Choose GPT-5.4 Nano when coding workflow support and lower input-token cost are central to the workload. Choose Grok 4.3 when reasoning depth and larger context windows are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency.
FAQ
Which has a larger context window, GPT-5.4 Nano or Grok 4.3?
Grok 4.3 supports 1M tokens, while GPT-5.4 Nano supports 400K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, GPT-5.4 Nano or Grok 4.3?
GPT-5.4 Nano is cheaper on tracked token pricing. GPT-5.4 Nano costs $0.2/1M input and $1.25/1M output tokens. Grok 4.3 costs $1.25/1M input and $2.5/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is GPT-5.4 Nano or Grok 4.3 open source?
GPT-5.4 Nano is listed under Proprietary. Grok 4.3 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 Nano or Grok 4.3?
Grok 4.3 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 Nano or Grok 4.3?
Both GPT-5.4 Nano and Grok 4.3 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.
Where can I run GPT-5.4 Nano and Grok 4.3?
GPT-5.4 Nano is available on OpenAI API and OpenRouter. Grok 4.3 is available on xAI Console and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-14. Data sourced from public model cards and provider documentation.