# Grok 4.20 vs DeepSeek V4 Flash

> Markdown mirror of https://router.one/models/compare/grok-4-20-vs-deepseek-v4-flash for AI assistants and crawlers. Router One is an OpenAI-compatible LLM API gateway.

Grok 4.20 and DeepSeek V4 Flash compared on current per-token rates, context window, and capabilities — both callable through one OpenAI-compatible endpoint with per-request cost traces.

## Grok 4.20 vs DeepSeek V4 Flash: rates, context window, and capabilities

| Spec | Grok 4.20 | DeepSeek V4 Flash |
| --- | --- | --- |
| Input / 1M tokens | $0.50 | $0.80 |
| Output / 1M tokens | $1.00 | $1.60 |
| Cached input / 1M tokens | $0.08 | $0.08 |
| Context window | 1.0M | 1.0M |
| Capabilities | Chat, Streaming, Tool calling | Chat, Streaming, Tool calling |
| Detail page | [Grok 4.20](https://router.one/models/grok-4-20-0309-non-reasoning) | [DeepSeek V4 Flash](https://router.one/models/deepseek-v4-flash) |

## What does 1M tokens cost on Grok 4.20 vs DeepSeek V4 Flash?

For a workload of 1M input plus 1M output tokens at current rates: Grok 4.20 comes to $1.50, DeepSeek V4 Flash comes to $2.40 — Grok 4.20 is about 38% cheaper on this mix. Real workloads skew heavily toward input tokens, so weigh the input rate by your own ratio; prompt-cache hits bill at the cached-input rate where supported.

## Switch between Grok 4.20 and DeepSeek V4 Flash without changing code

Both models are behind the same OpenAI-compatible endpoint, so an A/B test is a one-string change — same key, same code, and every request traced with tokens, cost, and latency in the dashboard:

`compare.sh`

```bash
curl https://api.router.one/v1/chat/completions \
  -H "Authorization: Bearer sk-your-router-one-key" \
  -H "Content-Type: application/json" \
  -d '{"model": "grok-4.20-0309-non-reasoning", "messages": [{"role": "user", "content": "Hello"}]}'

# Same request, other model — change one string:
#   "model": "deepseek-v4-flash"
```

## FAQ

### Is Grok 4.20 cheaper than DeepSeek V4 Flash?

At current posted rates, Grok 4.20 is the cheaper of the two (input $0.50 vs $0.80, output $1.00 vs $1.60 per 1M tokens). Rates change; the /models page is the live source of truth.

### Can I switch between Grok 4.20 and DeepSeek V4 Flash without changing code?

Yes. Both are served through the same OpenAI-compatible endpoint, so switching is changing the model string in the request — the key, base URL, and request shape stay identical.

### Where do these numbers come from?

Specs and prices on this page render from the live Router One catalog — the same data as the /models page — and refresh with it. Pricing methodology is documented on /pricing-methodology.

## More comparisons

- [Doubao Seed 2.0 Lite vs DeepSeek V4 Flash](https://router.one/models/compare/doubao-seed-2-0-lite-260428-vs-deepseek-v4-flash)
- [DeepSeek V4 Pro vs DeepSeek V4 Flash](https://router.one/models/compare/deepseek-v4-pro-vs-deepseek-v4-flash)

All model comparisons: https://router.one/models/compare

## See also

- Canonical page: https://router.one/models/compare/grok-4-20-vs-deepseek-v4-flash
- All models & prices: https://router.one/models (markdown: https://router.one/models.md)
- Pricing: https://router.one/pricing