Which is cheaper, Claude Fable 5.1 and DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash has the lowest input price. Per 1M input tokens: Claude Fable 5.1 from $10.00 and DeepSeek V4.1 Flash from $0.20.

Which has the larger context window, Claude Fable 5.1 and DeepSeek V4.1 Flash?

DeepSeek V4.1 Flash has the largest context window: Claude Fable 5.1 1,000,000 tokens and DeepSeek V4.1 Flash 1,048,576 tokens.

Which is smarter, Claude Fable 5.1 and DeepSeek V4.1 Flash?

Claude Fable 5.1 scores highest on the Artificial Analysis Intelligence Index: Claude Fable 5.1 51.2 and DeepSeek V4.1 Flash 39.5.

Can I switch between Claude Fable 5.1 and DeepSeek V4.1 Flash without changing my code?

Yes. All of them are served through FastRouter's OpenAI-compatible API, so switching is a change of the model parameter (anthropic/claude-fable-5.1, deepseek/deepseek-v4.1-flash).

Claude Fable 5.1 vs DeepSeek V4.1 Flash

Side-by-side pricing per provider, context window, benchmark scores and speed, all on one OpenAI-compatible API.

Claude Fable 5.1 Anthropicanthropic/claude-fable-5.1

DeepSeek V4.1 Flash DeepSeekdeepseek/deepseek-v4.1-flash

Creator

Anthropic

DeepSeek

Released

Sep 1, 2026

Sep 14, 2026

Context window

1.05M

Max output

128K

944K

Input / 1MLowest provider price

$10.00

$0.20$0.20–$0.30 across 5

Output / 1MLowest provider price

$50.00

$0.60$0.60–$1.20 across 5

Providers

IntelligenceArtificial Analysis index

51.2

39.5

CodingArtificial Analysis index

79.1

—

Accepts

Text, Image, Files

Text, Image

Produces

Text

Tool calling

Yes

Structured output

Yes

Reasoning

Yes

Claude Fable 5.1 vs DeepSeek V4.1 Flash: summary

Claude Fable 5.1 and DeepSeek V4.1 Flash are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Claude Fable 5.1, from Anthropic, has a 1,000,000-token context window, costs $10.00/1M input and $50.00/1M output tokens and scores 51.2 on the Artificial Analysis Intelligence Index.

DeepSeek V4.1 Flash, from DeepSeek, has a 1,048,576-token context window, costs from $0.20/1M input and $0.60/1M output tokens across 5 providers and scores 39.5 on the Artificial Analysis Intelligence Index.

DeepSeek V4.1 Flash is the cheapest on input, 50× cheaper than the next model, DeepSeek V4.1 Flash has the largest context window and Claude Fable 5.1 scores highest for intelligence.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="anthropic/claude-fable-5.1", messages=[...]) # or client.chat.completions.create(model="deepseek/deepseek-v4.1-flash", messages=[...])

Full API docs

Frequently asked questions

More comparisons

Benchmark scores sourced from ArtificialAnalysis