DeepSeek V4 Flash vs Grok 4.20
DeepSeek V4 Flash (2026) and Grok 4.20 (2026) are frontier-tier reasoning models from DeepSeek and xAI. DeepSeek V4 Flash ships a 1M-token context window, while Grok 4.20 ships a 2M-token context window. On SWE-bench Verified, DeepSeek V4 Flash leads by 2.3 pts. On pricing, DeepSeek V4 Flash costs $0.14/1M input tokens versus $1.25/1M for the alternative. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit.
DeepSeek V4 Flash is ~793% cheaper at $0.14/1M; pay for Grok 4.20 only for long-context analysis.
Specs
| Specification | ||
|---|---|---|
| Released | 2026-04-24 | 2026-01-01 |
| Context window | 1M | 2M |
| Parameters | 284B | — |
| Architecture | mixture of experts | - |
| License | MIT | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| Pricing attribute | DeepSeek V4 Flash | Grok 4.20 |
|---|---|---|
| Input price | $0.14/1M tokens | $1.25/1M tokens |
| Output price | $0.28/1M tokens | $2.5/1M tokens |
| Providers |
Capabilities
| Capability | DeepSeek V4 Flash | Grok 4.20 |
|---|---|---|
| Vision | No | No |
| Multimodal | No | No |
| Reasoning | Yes | Yes |
| Function calling | Yes | Yes |
| Tool use | Yes | Yes |
| Structured outputs | Yes | Yes |
| Code execution | No | No |
Benchmarks
| Benchmark | DeepSeek V4 Flash | Grok 4.20 |
|---|---|---|
| SWE-bench Verified | 79.0 | 76.7 |
Deep dive
On shared benchmark coverage, SWE-bench Verified has DeepSeek V4 Flash at 79 and Grok 4.20 at 76.7, with DeepSeek V4 Flash ahead by 2.3 points. The largest visible gap is 2.3 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 is close: both models cover reasoning mode, function calling, tool use, and structured outputs. 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, DeepSeek V4 Flash lists $0.14/1M input and $0.28/1M 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 DeepSeek V4 Flash lower by about $1.44 per million blended tokens. Availability is 2 providers versus 2, so concentration risk also matters.
Choose DeepSeek V4 Flash when provider fit 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.
FAQ
Which has a larger context window, DeepSeek V4 Flash or Grok 4.20?
Grok 4.20 supports 2M tokens, while DeepSeek V4 Flash supports 1M tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.
Which is cheaper, DeepSeek V4 Flash or Grok 4.20?
DeepSeek V4 Flash is cheaper on tracked token pricing. DeepSeek V4 Flash costs $0.14/1M input and $0.28/1M 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 DeepSeek V4 Flash or Grok 4.20 open source?
DeepSeek V4 Flash is listed under MIT. 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 reasoning mode, DeepSeek V4 Flash or Grok 4.20?
Both DeepSeek V4 Flash 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.
Which is better for function calling, DeepSeek V4 Flash or Grok 4.20?
Both DeepSeek V4 Flash and Grok 4.20 expose function calling. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.
Where can I run DeepSeek V4 Flash and Grok 4.20?
DeepSeek V4 Flash is available on DeepSeek Platform and OpenRouter. Grok 4.20 is available on xAI Console and OpenRouter. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-05-14. Data sourced from public model cards and provider documentation.