Grok Code Fast 1 vs Muse Spark 1.1

xAI · US  |  Meta · US · Updated June 2026

Quick verdict

Pick Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50 or low-latency code generation and terminal tasks. Pick Muse Spark 1.1 for scaled tool use — 88.1 on mcp atlas, ahead of opus 4.8 and gpt-5.5 (vendor-reported) or subagent orchestration — trained to run as a main agent or a subagent that escalates when stuck. On a tight budget at scale, Grok Code Fast 1 is the value pick.

Grok Code Fast 1 (xAI) and Muse Spark 1.1 (Meta) are two of the models people most often weigh against each other in 2026. Grok Code Fast 1 is xAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Muse Spark 1.1 is meta's first paid, closed-weight frontier model — class-leading agentic tool use at a quarter of rivals' price, but it trails on coding. They diverge most on price and context window — each quantified below from the models' real specs.

Key differences at a glance

Side-by-side specs

SpecGrok Code Fast 1Muse Spark 1.1
ProviderxAI (US) Meta (US)
ReleasedAugust 28, 2025 July 9, 2026
Context window256K (~384 pages) 1M (~1,573 pages)
Price (in/out)$0.2/$1.5 per 1M tokens $1.25/$4.25 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, code text, image, video, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published 54.1%

Who wins what

Fast, cheap agentic coding at $0.20/$1.50

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens it undercuts Muse Spark 1.1 ($1.25/$4.25 per 1M tokens), and that gap compounds at volume.

Low-latency code generation and terminal tasks

Grok Code Fast 1

XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality — and it runs cheaper at $0.2/$1.5 per 1M tokens.

High-volume coding pipelines where speed beats peak quality

Grok Code Fast 1

Muse Spark 1.1 is comparatively weak here — not the coding leader its launch framing implied — Meta's own report concedes it trails Opus 4.8 and GPT-5.5 on every coding benchmark

Scaled tool use — 88.1 on MCP Atlas, ahead of Opus 4.8 and GPT-5.5 (vendor-reported)

Muse Spark 1.1

Meta's first paid, closed-weight frontier model — class-leading agentic tool use at a quarter of rivals' price, but it trails on coding — and it carries the larger 1M context.

Subagent orchestration — trained to run as a main agent or a subagent that escalates when stuck

Muse Spark 1.1

Meta's first paid, closed-weight frontier model — class-leading agentic tool use at a quarter of rivals' price, but it trails on coding — and it is the newer of the two.

Professional agentic work — 54.7 on JobBench, a wide margin over rivals (vendor-reported)

Muse Spark 1.1

Muse Spark 1.1 lists professional agentic work — 54.7 on JobBench, a wide margin over rivals (vendor-reported) among its strengths; Grok Code Fast 1 does not.

Lowest cost at scale

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.

Largest single-prompt input

Muse Spark 1.1

Its 1M window is about 4.1× larger than Grok Code Fast 1's 256K, fitting roughly 1,573 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

Grok Code Fast 1

At $0.2/$1.5 per 1M tokens it undercuts Muse Spark 1.1, and on millions of tokens that margin decides the monthly bill.

Someone analysing very long documents or codebases

Muse Spark 1.1

Larger 1M window fits more in one prompt.

Anyone whose priority is fast, cheap agentic coding at $0.20/$1.50

Grok Code Fast 1

It is specifically built for that.

Anyone whose priority is scaled tool use — 88.1 on mcp atlas, ahead of opus 4.8 and gpt-5.5 (vendor-reported)

Muse Spark 1.1

That is its strongest area.

Grok Code Fast 1: where it fits

XAI's speed-tier coding model at $0.20/$1.50 with a 256K window — cheap, fast agentic code over frontier quality. Released August 28, 2025 by xAI, it is built for fast, cheap agentic coding at $0.20/$1.50, low-latency code generation and terminal tasks, high-volume coding pipelines where speed beats peak quality, and a 256K window sized for real codebases.

Its trade-offs are real: text and code only — no image, audio or video input, xAI did not publish a SWE-Bench Verified score, a speed-tier coding model, not a frontier reasoner, and narrow focus — built for code, not general knowledge work. At $0.2 in / $1.5 out per million tokens, it sits in the budget price band.

Muse Spark 1.1: where it fits

Meta's first paid, closed-weight frontier model — class-leading agentic tool use at a quarter of rivals' price, but it trails on coding. Released July 9, 2026 by Meta, it is built for scaled tool use — 88.1 on MCP Atlas, ahead of Opus 4.8 and GPT-5.5 (vendor-reported), subagent orchestration — trained to run as a main agent or a subagent that escalates when stuck, professional agentic work — 54.7 on JobBench, a wide margin over rivals (vendor-reported), and managing its own context: it compacts the 1M window mid-run instead of relying on external windowing.

Its trade-offs: not the coding leader its launch framing implied — Meta's own report concedes it trails Opus 4.8 and GPT-5.5 on every coding benchmark, the 1M window oversells its recall: 54.1 on MRCR v2 at 1M against GPT-5.5's 74.0, closed weights end the free, self-hostable Llama path — this is the first model Meta has charged for, and uS-only public preview behind a waitlist, and every benchmark is vendor-reported with no third-party replication. At $1.25 in / $4.25 out per million tokens, it sits in the mid price band.

The bottom line for this matchup

Grok Code Fast 1 and Muse Spark 1.1 overlap enough that the right pick depends on your specific job. Grok Code Fast 1 costs less per token; Muse Spark 1.1 holds the larger context; and each leads in its own area — Grok Code Fast 1 for fast, cheap agentic coding at $0.20/$1.50, Muse Spark 1.1 for scaled tool use — 88.1 on mcp atlas, ahead of opus 4.8 and gpt-5.5 (vendor-reported). Rather than crowning one, run the same hard task through both once and let the results decide.

Want both Grok Code Fast 1 and Muse Spark 1.1 without two subscriptions? LumiChats gives you these plus 40+ models under one ₹69/day pass (about $1/day) — draft with one, cross-check with the other.

See pricing

Frequently asked questions

Is Grok Code Fast 1 or Muse Spark 1.1 better for coding?

Public SWE-Bench figures are not available for either model, so the honest test is your own repository — run an identical real bug through both. By design, Grok Code Fast 1 leans toward fast, cheap agentic coding at $0.20/$1.50 while Muse Spark 1.1 leans toward scaled tool use — 88.1 on mcp atlas, ahead of opus 4.8 and gpt-5.5 (vendor-reported), and that positioning usually predicts which feels better on your codebase.

Which is cheaper, Grok Code Fast 1 or Muse Spark 1.1?

Grok Code Fast 1 is cheaper — $0.2/$1.5 per 1M tokens vs $1.25/$4.25 per 1M tokens, roughly 6.3× apart on input.

Which has the bigger context window?

Muse Spark 1.1 — 1M vs 256K, about 4.1× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both Grok Code Fast 1 and Muse Spark 1.1 together?

Yes — a multi-model platform like LumiChats gives you Grok Code Fast 1, Muse Spark 1.1 and 40+ others under one ₹69/day pass (about $1/day), so you can draft with one and cross-check with the other instead of buying two subscriptions.

Which is newer, Grok Code Fast 1 or Muse Spark 1.1?

Muse Spark 1.1 — released July 9, 2026, about 11 months after Grok Code Fast 1.

Related comparisons

Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.