Grok Code Fast 1 vs o3
Grok Code Fast 1 (2025) and o3 (2025) compare a coding-specialized model against a standalone API model. Grok Code Fast 1 ships a 262k-token context window, while o3 ships a 200k-token context window. On SWE-bench Verified, o3 leads by 0.9 pts. On pricing, Grok Code Fast 1 costs $0.20/1M input tokens versus $2/1M for the alternative. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Grok Code Fast 1 is coding-specialized model, while o3 is standalone API model. Choose based on workflow fit before reading any benchmark or price row as decisive.
Decision scorecard
Local evidence first| Signal | Grok Code Fast 1 | o3 |
|---|---|---|
| Product type | Coding-specialized model | Standalone API model |
| Best for | custom coding agents, code generation, and tool loops | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 262k | 200k |
| Cheapest output | $1.50/1M tokens | $8/1M tokens |
| Provider routes | 3 tracked | 3 tracked |
| Shared benchmarks | 1 shared | SWE-bench Verified leader |
Decision tradeoffs
- Grok Code Fast 1 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Grok Code Fast 1 has the lower cheapest tracked output price at $1.50/1M tokens.
- Local decision data tags Grok Code Fast 1 for Coding, RAG, and Agents.
- o3 holds a shared-benchmark lead on SWE-bench Verified, ahead by 0.9 points.
- o3 uniquely exposes Vision, Multimodal, and Reasoning in local model data.
- Local decision data tags o3 for Coding, RAG, and Agents.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Grok Code Fast 1
$535
Cheapest tracked route/tier: OpenRouter
o3
$3,600
Cheapest tracked route/tier: OpenAI API
Estimated monthly gap: $3,065. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.
Switch friction
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- o3 is $6.50/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- o3 adds Vision, Multimodal, and Reasoning in local capability data.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok Code Fast 1 is $6.50/1M 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.
Specs
| Specification | ||
|---|---|---|
| Released | 2025-08-27 | 2025-04-16 |
| Context window | 262k | 200k |
| Parameters | 314B | — |
| Architecture | Mixture of Experts | Decoder Only |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use: conditional | Commercial use: conditional |
| Knowledge cutoff | - | 2024-06 |
Pricing and availability
| Pricing attribute | Grok Code Fast 1 | o3 |
|---|---|---|
| Input price | $0.20/1M tokens | $2/1M tokens |
| Output price | $1.50/1M tokens | $8/1M tokens |
| Providers |
Capabilities
| Capability | Grok Code Fast 1 | o3 |
|---|---|---|
| Vision | No | Yes |
| Multimodal | No | Yes |
| Reasoning | No | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | Yes |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Grok Code Fast 1 | o3 |
|---|---|---|
| SWE-bench Verified | 70.8 | 71.7 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has Grok Code Fast 1 at 70.8 and o3 at 71.7, with o3 ahead by 0.9 points. The largest visible gap is 0.9 points on SWE-bench Verified, 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: o3, multimodal input: o3, reasoning mode: o3, and code execution: o3. 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 Code Fast 1 lists $0.20/1M input and $1.50/1M output tokens on the cheapest tracked provider, while o3 lists $2/1M input and $8/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Grok Code Fast 1 lower by about $3.21 per million blended tokens. Availability is 3 providers versus 3, so concentration risk also matters.
Choose Grok Code Fast 1 when coding workflow support, larger context windows, and lower input-token cost are central to the workload. Choose o3 when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.
FAQ
Which has a larger context window, Grok Code Fast 1 or o3?
Grok Code Fast 1 supports 262k tokens, while o3 supports 200k 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 Code Fast 1 or o3?
Grok Code Fast 1 is cheaper on tracked token pricing. Grok Code Fast 1 costs $0.20/1M input and $1.50/1M output tokens. o3 costs $2/1M input and $8/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok Code Fast 1 or o3 open source?
Grok Code Fast 1 is listed under Proprietary. o3 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 Code Fast 1 or o3?
o3 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 Code Fast 1 or o3?
o3 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 Code Fast 1 and o3?
Grok Code Fast 1 is available on OpenRouter, Microsoft Foundry, and xAI Console. o3 is available on OpenAI API, OpenRouter, and Vercel AI Gateway. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-15. Data sourced from public model cards and provider documentation.