Grok 4.6 or Muse Spark 1.3: which to choose?

The match-up at a glance

This comparison pits the flagship models of two major developers against each other: Grok 4.6 and Muse Spark 1.3, one from xAI, the other from Meta. The first dates from August 12, 2026, the second from September 2, 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, Grok 4.6 scores 86.1 out of 100 and Muse Spark 1.3 82.7. Grok 4.6 leads by 3.4 points.

On the 3 benchmarks reported for both, Grok 4.6 wins 1 time and Muse Spark 1.3 1:

• OTIS Mock AIME (competition mathematics problems): Grok 4.6 99.2%, Muse Spark 1.3 99.2%
• FrontierMath (very hard research-level mathematics): Grok 4.6 66%, Muse Spark 1.3 74.4%
• APEX-Agents (professional tasks carried out by an agent): Grok 4.6 65.3%, Muse Spark 1.3 58.6%

Which one costs less?

Grok 4.6 costs $2 per million input tokens and $6 per million output tokens; Muse Spark 1.3 costs $0.10 and $0.20.

For a typical agent task (read 20,000 tokens, write 2,000), expect $0.052 with Grok 4.6 versus $0.002 with Muse Spark 1.3. Muse Spark 1.3 is 21.7 times cheaper, a gap that adds up quickly over 1,000 tasks: $49.6 difference.

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

Under the hood

Muse Spark 1.3 reads more in one go: 1,048,576 tokens of context (roughly 1,573 pages), versus 500,000 for Grok 4.6.

Reasoning mode: Grok 4.6 yes, Muse Spark 1.3 yes. Tool calling: Grok 4.6 yes, Muse Spark 1.3 yes. Image input: Grok 4.6 yes, Muse Spark 1.3 yes.

Neither publishes its weights: both are used through an API.

In short

Our reading of the data:

• Choose Grok 4.6 for a higher capability index.
• Choose Muse Spark 1.3 for a lower cost and a larger context window.

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