Grok Build 0.1 vs Step 3.5 Flash
Grok Build 0.1 (2026) and Step 3.5 Flash (2026) compare a coding-specialized model against a standalone API model. Grok Build 0.1 ships a 256k-token context window, while Step 3.5 Flash ships a 256k-token context window. On SWE-bench Verified, Step 3.5 Flash leads by 3.6 pts. This page treats the result as workflow and deployment fit, not a universal model winner.
Treat this as a product-type comparison: Grok Build 0.1 is coding-specialized model, while Step 3.5 Flash 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 Build 0.1 | Step 3.5 Flash |
|---|---|---|
| Product type | Coding-specialized model | Standalone API model |
| Best for | custom coding agents, code generation, and tool loops | reasoning-heavy apps |
| Decision fit | Coding, RAG, and Agents | Coding, Agents, and Long context |
| Context window | 256k | 256k |
| Cheapest output | $2/1M tokens | $0.30/1M tokens |
| Provider routes | 3 tracked | 1 tracked |
| Shared benchmarks | 1 rows | SWE-bench Verified leader |
Decision tradeoffs
- Grok Build 0.1 has broader tracked provider coverage for fallback and procurement flexibility.
- Grok Build 0.1 uniquely exposes Vision, Multimodal, and Function calling in local model data.
- Local decision data tags Grok Build 0.1 for Coding, RAG, and Agents.
- Step 3.5 Flash holds a shared-benchmark lead on SWE-bench Verified, ahead by 3.6 points.
- Step 3.5 Flash has the lower cheapest tracked output price at $0.30/1M tokens.
- Local decision data tags Step 3.5 Flash for Coding, Agents, and Long context.
Monthly cost at traffic
Estimate token spend from the cheapest tracked input and output route or tier on this page.
Grok Build 0.1
$1,300
Cheapest tracked route/tier: xAI Console
Step 3.5 Flash
$155
Cheapest tracked route/tier: OpenRouter
Estimated monthly gap: $1,145. 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.
- Step 3.5 Flash is $1.70/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Check replacement coverage for Vision, Multimodal, and Function calling before moving production traffic.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok Build 0.1 is $1.70/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
- Grok Build 0.1 adds Vision, Multimodal, and Function calling in local capability data.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-05-14 | 2026-01-29 |
| Context window | 256k | 256k |
| Parameters | — | 196B (11B active) |
| Architecture | - | mixture of experts |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | Grok Build 0.1 | Step 3.5 Flash |
|---|---|---|
| Input price |
| $0.10/1M tokens |
| Output price |
| $0.30/1M tokens |
| Providers |
Capabilities
| Capability | Grok Build 0.1 | Step 3.5 Flash |
|---|---|---|
| Vision | Yes | No |
| Multimodal | Yes | No |
| Reasoning | Yes | Yes |
| Function calling | Yes | No |
| Tool use | Yes | No |
| Structured outputs | Yes | No |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Grok Build 0.1 | Step 3.5 Flash |
|---|---|---|
| SWE-bench Verified | 70.8 | 74.4 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has Grok Build 0.1 at 70.8 and Step 3.5 Flash at 74.4, with Step 3.5 Flash ahead by 3.6 points. The largest visible gap is 3.6 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: Grok Build 0.1, multimodal input: Grok Build 0.1, function calling: Grok Build 0.1, tool use: Grok Build 0.1, and structured outputs: Grok Build 0.1. Both models share reasoning mode, 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 Build 0.1 lists tiered pricing: 0-200,001t is $1/1M input and $2/1M output; 200,001t+ is $2/1M input and $4/1M output, while Step 3.5 Flash lists $0.10/1M input and $0.30/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Step 3.5 Flash lower by about $1.14 per million blended tokens. For tiered rows, this cheapest-track view can understate interactive or fast-lane spend, so compare the tier you will actually use. Availability is 3 providers versus 1, so concentration risk also matters.
Choose Grok Build 0.1 when coding workflow support and broader provider choice are central to the workload. Choose Step 3.5 Flash when provider fit 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.
FAQ
Which has a larger context window, Grok Build 0.1 or Step 3.5 Flash?
Grok Build 0.1 supports 256k tokens, while Step 3.5 Flash supports 256k 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 Build 0.1 or Step 3.5 Flash?
Grok Build 0.1 lists tiered pricing: 0-200,001t is $1/1M input and $2/1M output; 200,001t+ is $2/1M input and $4/1M output. Step 3.5 Flash lists $0.10/1M input and $0.30/1M output tokens on the cheapest tracked provider. Compare the tier you will actually use; cheap async pricing can overstate savings for interactive workflows. Provider discounts or batch pricing can still change the final bill.
Is Grok Build 0.1 or Step 3.5 Flash open source?
Grok Build 0.1 is listed under Proprietary. Step 3.5 Flash 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 Build 0.1 or Step 3.5 Flash?
Grok Build 0.1 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.
Which is better for multimodal input, Grok Build 0.1 or Step 3.5 Flash?
Grok Build 0.1 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 Build 0.1 and Step 3.5 Flash?
Grok Build 0.1 is available on xAI Console, Vercel AI Gateway, and OpenRouter. Step 3.5 Flash is available on OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-06-06. Data sourced from public model cards and provider documentation.