Grok 4.3 vs Grok Code Fast 1
Grok 4.3 (2026) and Grok Code Fast 1 (2025) are agentic coding models from xAI. Grok 4.3 ships a 1M-token context window, while Grok Code Fast 1 ships a 262K-token context window. On pricing, Grok Code Fast 1 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.
Grok Code Fast 1 is ~525% cheaper at $0.2/1M; pay for Grok 4.3 only for reasoning depth.
Decision scorecard
Local evidence first| Signal | Grok 4.3 | Grok Code Fast 1 |
|---|---|---|
| Decision fit | RAG, Agents, and Long context | Coding, RAG, and Agents |
| Context window | 1M | 262K |
| Cheapest output | $2.5/1M tokens | $1.5/1M tokens |
| Provider routes | 2 tracked | 1 tracked |
| Shared benchmarks | 0 rows | 0 rows |
Decision tradeoffs
- Grok 4.3 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Grok 4.3 has broader tracked provider coverage for fallback and procurement flexibility.
- Grok 4.3 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags Grok 4.3 for RAG, Agents, and Long context.
- Grok Code Fast 1 has the lower cheapest tracked output price at $1.5/1M tokens.
- Local decision data tags Grok Code Fast 1 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output prices on this page.
Grok 4.3
$1,625
Cheapest tracked route: xAI Console
Grok Code Fast 1
$535
Cheapest tracked route: OpenRouter
Estimated monthly gap: $1,090. 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 Code Fast 1 is $1/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Reasoning before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4.3 is $1/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Grok 4.3 adds Vision, Multimodal, and Reasoning in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-05 | 2025-08-27 |
| Context window | 1M | 262K |
| Parameters | ~0.5T | 314B |
| Architecture | - | mixture of experts |
| License | Proprietary | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Grok 4.3 | Grok Code Fast 1 |
|---|---|---|
| Input price | $1.25/1M tokens | $0.2/1M tokens |
| Output price | $2.5/1M tokens | $1.5/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.3 | Grok Code Fast 1 |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | No |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: Grok 4.3, multimodal input: Grok 4.3, and reasoning mode: Grok 4.3. Both models share 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, Grok 4.3 lists $1.25/1M input and $2.5/1M output tokens, while Grok Code Fast 1 lists $0.2/1M input and $1.5/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok Code Fast 1 lower by about $1.04 per million blended tokens. Availability is 2 providers versus 1, so concentration risk also matters.
Choose Grok 4.3 when reasoning depth, larger context windows, and broader provider choice are central to the workload. Choose Grok Code Fast 1 when coding workflow support and lower input-token cost 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.
FAQ
Which has a larger context window, Grok 4.3 or Grok Code Fast 1?
Grok 4.3 supports 1M tokens, while Grok Code Fast 1 supports 262K tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, Grok 4.3 or Grok Code Fast 1?
Grok Code Fast 1 is cheaper on tracked token pricing. Grok 4.3 costs $1.25/1M input and $2.5/1M output tokens. Grok Code Fast 1 costs $0.2/1M input and $1.5/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.3 or Grok Code Fast 1 open source?
Grok 4.3 is listed under Proprietary. Grok Code Fast 1 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, Grok 4.3 or Grok Code Fast 1?
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, Grok 4.3 or Grok Code Fast 1?
Grok 4.3 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.
Where can I run Grok 4.3 and Grok Code Fast 1?
Grok 4.3 is available on xAI Console and OpenRouter. Grok Code Fast 1 is available on OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Continue comparing
Last reviewed: 2026-05-14. Data sourced from public model cards and provider documentation.