# Claude Haiku 5.5 vs DeepSeek V4.1 Flash

> Markdown mirror of https://router.one/models/compare/claude-haiku-5-5-vs-deepseek-v4-1-flash for AI assistants and crawlers. Router One is a unified, OpenAI-compatible LLM API gateway.

Claude Haiku 5.5 is the lower-priced of the two on Router One at base-tier rates (Claude Haiku 5.5: request input ≤ 100,000 tokens) — about 88% less on a 1M-input + 1M-output mix. Claude Haiku 5.5 offers 1.05M of context vs 1M for DeepSeek V4.1 Flash. Claude Haiku 5.5 answers on /v1/chat/completions and /v1/messages (Claude Code); DeepSeek V4.1 Flash on /v1/chat/completions, /v1/messages (Claude Code) and /v1/responses (Codex CLI).

Claude Haiku 5.5 and DeepSeek V4.1 Flash compared on current per-token rates, context window, and capabilities — both callable through one OpenAI-compatible endpoint with per-request cost traces.

## Claude Haiku 5.5 vs DeepSeek V4.1 Flash: rates, context window, and capabilities

| Spec | Claude Haiku 5.5 | DeepSeek V4.1 Flash |
| --- | --- | --- |
| Input / 1M tokens | $0.06 | $0.60 |
| Output / 1M tokens | $0.30 | $2.40 |
| Cached input / 1M tokens | $0.006 | $0.012 |
| Context window | 1.05M | 1M |
| Capabilities | Chat, Streaming, Tool calling, Vision | Chat, Streaming, Tool calling, Vision |
| Subscription plans | Not in any plan — wallet | Not in any plan — wallet |
| Detail page | [Claude Haiku 5.5](https://router.one/models/claude-haiku-5-5) | [DeepSeek V4.1 Flash](https://router.one/models/deepseek-v4-1-flash) |

Claude Haiku 5.5: request input ≤ 100,000 tokens: Input $0.06 / 1M tokens, Output $0.30 / 1M tokens, Cache write $0.075 / 1M tokens, Cached input $0.006 / 1M tokens; request input > 100,000 tokens: Input $0.30 / 1M tokens, Output $1.50 / 1M tokens, Cache write $0.375 / 1M tokens, Cached input $0.03 / 1M tokens. The total input tokens in each request select the tier; its rates apply to the whole request, not only tokens above the threshold.

## What does 1M tokens cost on Claude Haiku 5.5 vs DeepSeek V4.1 Flash?

Base-tier rates: For a workload of 1M input plus 1M output tokens at current rates: Claude Haiku 5.5 comes to $0.36, DeepSeek V4.1 Flash comes to $3.00 — Claude Haiku 5.5 is about 88% cheaper on this mix. Real workloads skew heavily toward input tokens, so weigh the input rate by your own ratio; the cached-input row above is the posted catalog rate for that model.

## Switch between Claude Haiku 5.5 and DeepSeek V4.1 Flash

The API key and base URL stay the same, but this is not a one-string switch for every client. Router One serves Claude Haiku 5.5 on /v1/messages and /v1/chat/completions and DeepSeek V4.1 Flash on /v1/chat/completions, /v1/messages and /v1/responses, so Codex CLI (/v1/responses) runs only the DeepSeek side. Requests written for DeepSeek V4.1 Flash may need changes first: per Anthropic's Claude Haiku 5.5 migration guide (checked 2026-10-10), Claude Haiku 5.5 returns a 400 for sampling settings it does not accept (omit temperature, top_p and top_k) and for an assistant prefill as the last turn.

`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": "anthropic/claude-haiku-5.5", "messages": [{"role": "user", "content": "Hello"}]}'

# Same request, other model — change one string:
#   "model": "deepseek-v4.1-flash"
```

## FAQ

### Is Claude Haiku 5.5 cheaper than DeepSeek V4.1 Flash?

Compared at base-tier rates (Claude Haiku 5.5: request input ≤ 100,000 tokens). Input: Claude Haiku 5.5 $0.06 vs DeepSeek V4.1 Flash $0.60 / 1M tokens; Claude Haiku 5.5 has the lower rate. Output: Claude Haiku 5.5 $0.30 vs DeepSeek V4.1 Flash $2.40 / 1M tokens; Claude Haiku 5.5 has the lower rate. Total cost depends on the workload's input, output and cache usage. Claude Haiku 5.5: request input ≤ 100,000 tokens: Input $0.06 / 1M tokens, Output $0.30 / 1M tokens, Cache write $0.075 / 1M tokens, Cached input $0.006 / 1M tokens; request input > 100,000 tokens: Input $0.30 / 1M tokens, Output $1.50 / 1M tokens, Cache write $0.375 / 1M tokens, Cached input $0.03 / 1M tokens. The total input tokens in each request select the tier; its rates apply to the whole request, not only tokens above the threshold. Rates change; the /models page is the live source of truth.

### Is Claude Haiku 5.5 or DeepSeek V4.1 Flash included in a Router One subscription?

Neither Claude Haiku 5.5 nor DeepSeek V4.1 Flash is in a Router One plan, so every call to either bills the wallet per token.

### Can I switch between Claude Haiku 5.5 and DeepSeek V4.1 Flash without changing code?

The API key and base URL stay the same, but this is not a one-string switch for every client. Router One serves Claude Haiku 5.5 on /v1/messages and /v1/chat/completions and DeepSeek V4.1 Flash on /v1/chat/completions, /v1/messages and /v1/responses, so Codex CLI (/v1/responses) runs only the DeepSeek side. Requests written for DeepSeek V4.1 Flash may need changes first: per Anthropic's Claude Haiku 5.5 migration guide (checked 2026-10-10), Claude Haiku 5.5 returns a 400 for sampling settings it does not accept (omit temperature, top_p and top_k) and for an assistant prefill as the last turn.

### 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. Rates on this page were read from the live catalog on 2026-10-28 (UTC) and refresh within the hour.

## More comparisons

- [Claude Haiku 5.5 vs Claude Sonnet 5.5](https://router.one/models/compare/claude-haiku-5-5-vs-claude-sonnet-5-5)
- [DeepSeek V4.1 Flash vs Gemini 3.8 Flash](https://router.one/models/compare/deepseek-v4-1-flash-vs-gemini-3-8-flash)
- [DeepSeek V4.1 Flash vs Claude Haiku 4.5](https://router.one/models/compare/deepseek-v4-1-flash-vs-claude-haiku-4-5)
- [Claude Haiku 5.5 vs Claude Haiku 4.5](https://router.one/models/compare/claude-haiku-5-5-vs-claude-haiku-4-5)

## See also

- Canonical page: https://router.one/models/compare/claude-haiku-5-5-vs-deepseek-v4-1-flash
- All model comparisons: https://router.one/models/compare
- All models & prices: https://router.one/models (markdown: https://router.one/models.md)
- Pricing: https://router.one/pricing
- Claude API access: https://router.one/cheap-claude-api
- OpenAI-compatible API: https://router.one/openai-compatible-api
- Claude Haiku 5.5 API guide: https://router.one/blog/claude-haiku-5-5-api-guide
- Cost calculator: https://router.one/llm-cost-calculator
- Pricing methodology: https://router.one/pricing-methodology