DeepSeek V4.1 Flash 1017 or Muse Spark Open: which to choose?

What are we comparing?

This comparison pits two open-weight models that you can install on your own servers against each other: DeepSeek V4.1 Flash 1017 and Muse Spark Open, one from DeepSeek, the other from Meta. The first dates from October 17, 2026, the second from October 15, 2026.

All figures below come from public sources checked on October 22, 2026: models.dev and OpenRouter for prices and capabilities, Epoch AI for scores.

Which one is more capable?

On our capability index, DeepSeek V4.1 Flash 1017 scores 90.6 out of 100 and Muse Spark Open 75.2. DeepSeek V4.1 Flash 1017 leads by 15.4 points.

On the 3 benchmarks reported for both, DeepSeek V4.1 Flash 1017 wins 3 times and Muse Spark Open 0:

• GPQA Diamond (PhD-level science questions): DeepSeek V4.1 Flash 1017 93.2%, Muse Spark Open 88.6%
• OTIS Mock AIME (competition mathematics problems): DeepSeek V4.1 Flash 1017 99.4%, Muse Spark Open 98.1%
• FrontierMath (very hard research-level mathematics): DeepSeek V4.1 Flash 1017 71.2%, Muse Spark Open 69.8%

Budget

DeepSeek V4.1 Flash 1017 costs $0.15 per million input tokens and $0.60 per million output tokens; Muse Spark Open costs $1.25 and $4.25.

For a typical agent task (read 20,000 tokens, write 2,000), expect $0.004 with DeepSeek V4.1 Flash 1017 versus $0.034 with Muse Spark Open. DeepSeek V4.1 Flash 1017 is 8 times cheaper, a gap that adds up quickly over 1,000 tasks: $29.3 difference.

Run the numbers with your own volumes in the agent cost calculator.

Context and capabilities

Both models have the same context window: 1,048,576 tokens, roughly 1,573 pages.

Reasoning mode: DeepSeek V4.1 Flash 1017 yes, Muse Spark Open yes. Tool calling: DeepSeek V4.1 Flash 1017 yes, Muse Spark Open yes. Image input: DeepSeek V4.1 Flash 1017 yes, Muse Spark Open yes.

Both publish their weights: you can host them yourself.

Knowledge cutoff: May 2025 for DeepSeek V4.1 Flash 1017, January 4, 2026 for Muse Spark Open.

In short

Our reading of the data:

• Choose DeepSeek V4.1 Flash 1017 for a higher capability index and a lower cost.

This verdict relies on public figures; it does not replace a trial on your own tasks.