GPT-5.4 Mini vs Muse Spark 1.1

OpenAI · US  |  Meta · US · Updated June 2026

Quick verdict

Pick GPT-5.4 Mini for free for every chatgpt user or fast, low-cost general 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, GPT-5.4 Mini is the value pick.

GPT-5.4 Mini (OpenAI) and Muse Spark 1.1 (Meta) are two of the models people most often weigh against each other in 2026. GPT-5.4 Mini is openAI's free, fast workhorse — capable general AI with no subscription needed. 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

SpecGPT-5.4 MiniMuse Spark 1.1
ProviderOpenAI (US) Meta (US)
ReleasedMarch 17, 2026 July 9, 2026
Context window400K (~600 pages) 1M (~1,573 pages)
Price (in/out)$0.75/$4.5 per 1M tokens $1.25/$4.25 per 1M tokens
Open weight?No — API only No — API only
Modalitiestext, image, code text, image, video, code
SWE-Bench VerifiedNot published Not published
MRCR v2 @ 1MNot published 54.1%

Who wins what

Free for every ChatGPT user

GPT-5.4 Mini

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

Fast, low-cost general tasks

GPT-5.4 Mini

At $0.75/$4.5 per 1M tokens it undercuts Muse Spark 1.1 ($1.25/$4.25 per 1M tokens), and that gap compounds at volume.

Subagent capabilities

GPT-5.4 Mini

OpenAI's free, fast workhorse — capable general AI with no subscription needed — and it runs cheaper at $0.75/$4.5 per 1M tokens.

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; GPT-5.4 Mini does not.

Lowest cost at scale

GPT-5.4 Mini

At $0.75/$4.5 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 2.6× larger than GPT-5.4 Mini's 400K, fitting roughly 1,573 pages in one prompt.

Which should you pick?

A cost-sensitive startup shipping high volume

GPT-5.4 Mini

At $0.75/$4.5 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 free for every chatgpt user

GPT-5.4 Mini

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.

GPT-5.4 Mini: where it fits

OpenAI's free, fast workhorse — capable general AI with no subscription needed. Released March 17, 2026 by OpenAI, it is built for free for every ChatGPT user, fast, low-cost general tasks, subagent capabilities, and native multimodal reasoning.

Its trade-offs are real: smaller context than flagship models, and not for the hardest reasoning. At $0.75 in / $4.5 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

GPT-5.4 Mini and Muse Spark 1.1 overlap enough that the right pick depends on your specific job. GPT-5.4 Mini costs less per token; Muse Spark 1.1 holds the larger context; and each leads in its own area — GPT-5.4 Mini for free for every chatgpt user, 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 GPT-5.4 Mini 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 GPT-5.4 Mini 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, GPT-5.4 Mini leans toward free for every chatgpt user 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, GPT-5.4 Mini or Muse Spark 1.1?

GPT-5.4 Mini is cheaper — $0.75/$4.5 per 1M tokens vs $1.25/$4.25 per 1M tokens, roughly 1.7× apart on input.

Which has the bigger context window?

Muse Spark 1.1 — 1M vs 400K, about 2.6× larger. Useful only if the model actually reasons over the full window, which not all do.

Can I use both GPT-5.4 Mini and Muse Spark 1.1 together?

Yes — a multi-model platform like LumiChats gives you GPT-5.4 Mini, 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, GPT-5.4 Mini or Muse Spark 1.1?

Muse Spark 1.1 — released July 9, 2026, about 4 months after GPT-5.4 Mini.

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.