Grok 4.20 vs Step 3.7 Flash
Grok 4.20 (2026) and Step 3.7 Flash (2026) are frontier-tier reasoning models from xAI and StepFun. Grok 4.20 ships a 1m-token context window, while Step 3.7 Flash ships a 256k-token context window. On Humanity's Last Exam, Step 3.7 Flash leads by 15 pts. On pricing, Step 3.7 Flash costs $0.20/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.
Step 3.7 Flash is ~525% cheaper at $0.20/1M; pay for Grok 4.20 only for long-context analysis.
Decision scorecard
Local evidence first| Signal | Grok 4.20 | Step 3.7 Flash |
|---|---|---|
| Best for | reasoning-heavy apps, multimodal apps, and tool-calling agents | reasoning-heavy apps, multimodal apps, and tool-calling agents |
| Decision fit | Coding, RAG, and Agents | Coding, RAG, and Agents |
| Context window | 1m | 256k |
| Cheapest output | $2.50/1M tokens | $1.15/1M tokens |
| Provider routes | 2 tracked | 3 tracked |
| Shared benchmarks | 1 rows | Humanity's Last Exam leader |
Decision tradeoffs
- Grok 4.20 has the larger context window for long prompts, retrieval packs, or transcript analysis.
- Local decision data tags Grok 4.20 for Coding, RAG, and Agents.
- Step 3.7 Flash holds a shared-benchmark lead on Humanity's Last Exam, ahead by 15 points.
- Step 3.7 Flash has the lower cheapest tracked output price at $1.15/1M tokens.
- Step 3.7 Flash has broader tracked provider coverage for fallback and procurement flexibility.
- Local decision data tags Step 3.7 Flash 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 4.20
$1,625
Cheapest tracked route/tier: xAI Console
Step 3.7 Flash
$448
Cheapest tracked route/tier: StepFun
Estimated monthly gap: $1,178. 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 3.7 Flash is $1.35/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
- Provider overlap exists on OpenRouter; start route-level A/B tests there.
- Grok 4.20 is $1.35/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-02-17 | 2026-05-29 |
| Context window | 1m | 256k |
| Parameters | — | 198B (11B active) |
| Architecture | - | mixture of experts |
| License | Proprietary | Proprietary |
| Openness | Proprietary | Proprietary |
| Commercial use | Commercial use with conditions | Commercial use with conditions |
| Knowledge cutoff | 2024-11 | - |
Pricing and availability
| Pricing attribute | Grok 4.20 | Step 3.7 Flash |
|---|---|---|
| Input price | $1.25/1M tokens | $0.20/1M tokens |
| Output price | $2.50/1M tokens | $1.15/1M tokens |
| Providers |
Capabilities
| Capability | Grok 4.20 | Step 3.7 Flash |
|---|---|---|
| Vision | Yes | Yes |
| Multimodal | Yes | Yes |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
| IDE integration | No | No |
| Computer use | No | No |
| Parallel agents | No | No |
Benchmarks
| Benchmark | Grok 4.20 | Step 3.7 Flash |
|---|---|---|
| Humanity's Last Exam | 32.2 | 47.2 |
Deep dive
On shared benchmark coverage, Humanity's Last Exam has Grok 4.20 at 32.2 and Step 3.7 Flash at 47.2, with Step 3.7 Flash ahead by 15 points. The largest visible gap is 15 points on Humanity's Last Exam, 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 is close: both models cover vision, multimodal input, reasoning mode, function calling, and tool use. That makes context budget, benchmark fit, and provider maturity more important than a simple checklist. If your application depends on one integration detail, verify it against the provider route you plan to use, not just the base model listing.
For cost, Grok 4.20 lists $1.25/1M input and $2.50/1M output tokens on the cheapest tracked provider, while Step 3.7 Flash lists $0.20/1M input and $1.15/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Step 3.7 Flash lower by about $1.14 per million blended tokens. Availability is 2 providers versus 3, so concentration risk also matters.
Choose Grok 4.20 when long-context analysis and larger context windows are central to the workload. Choose Step 3.7 Flash when vision-heavy evaluation, lower input-token cost, and broader provider choice 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 4.20 or Step 3.7 Flash?
Grok 4.20 supports 1m tokens, while Step 3.7 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 4.20 or Step 3.7 Flash?
Step 3.7 Flash is cheaper on tracked token pricing. Grok 4.20 costs $1.25/1M input and $2.50/1M output tokens. Step 3.7 Flash costs $0.20/1M input and $1.15/1M output tokens. Provider discounts or batch pricing can still change the final bill.
Is Grok 4.20 or Step 3.7 Flash open source?
Grok 4.20 is listed under Proprietary. Step 3.7 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 4.20 or Step 3.7 Flash?
Both Grok 4.20 and Step 3.7 Flash expose vision. 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.
Which is better for multimodal input, Grok 4.20 or Step 3.7 Flash?
Both Grok 4.20 and Step 3.7 Flash expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run Grok 4.20 and Step 3.7 Flash?
Grok 4.20 is available on xAI Console and OpenRouter. Step 3.7 Flash is available on StepFun, OpenRouter, and NVIDIA NIM. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-29. Data sourced from public model cards and provider documentation.