GPT-5.4 Mini vs Grok 4.20
GPT-5.4 Mini (2026) and Grok 4.20 (2026) are frontier-tier reasoning models from OpenAI and xAI. GPT-5.4 Mini ships a 400K-token context window, while Grok 4.20 ships a 2M-token context window. On pricing, GPT-5.4 Mini costs $0.75/1M 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 Mini is ~67% cheaper at $0.75/1M; pay for Grok 4.20 only for long-context analysis.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-03-05 | 2026-01-01 |
| Context window | 400K | 2M |
| Parameters | — | — |
| Architecture | decoder only | - |
| License | Proprietary | Proprietary |
| Knowledge cutoff | 2025-08 | - |
Pricing and availability
| Pricing attribute | GPT-5.4 Mini | Grok 4.20 |
|---|---|---|
| Input price | $0.75/1M tokens | $1.25/1M tokens |
| Output price | $4.5/1M tokens | $2.5/1M tokens |
| Providers |
Capabilities
| Capability | GPT-5.4 Mini | Grok 4.20 |
|---|---|---|
| Vision | No | No |
| Multimodal | Yes | No |
| Reasoning | Yes | 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 multimodal input: GPT-5.4 Mini and code execution: GPT-5.4 Mini. Both models share reasoning mode, 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 Mini lists $0.75/1M input and $4.5/1M output tokens, while Grok 4.20 lists $1.25/1M input and $2.5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok 4.20 lower by about $0.25 per million blended tokens. Availability is 2 providers versus 2, so concentration risk also matters.
Choose GPT-5.4 Mini when coding workflow support and lower input-token cost are central to the workload. Choose Grok 4.20 when long-context analysis 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 Mini or Grok 4.20?
Grok 4.20 supports 2M tokens, while GPT-5.4 Mini 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 Mini or Grok 4.20?
GPT-5.4 Mini is cheaper on tracked token pricing. GPT-5.4 Mini costs $0.75/1M input and $4.5/1M output tokens. Grok 4.20 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 Mini or Grok 4.20 open source?
GPT-5.4 Mini is listed under Proprietary. Grok 4.20 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 multimodal input, GPT-5.4 Mini or Grok 4.20?
GPT-5.4 Mini has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for reasoning mode, GPT-5.4 Mini or Grok 4.20?
Both GPT-5.4 Mini and Grok 4.20 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 Mini and Grok 4.20?
GPT-5.4 Mini is available on OpenAI API and OpenRouter. Grok 4.20 is available on xAI Console and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
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Last reviewed: 2026-05-14. Data sourced from public model cards and provider documentation.