Pick GPT-5.4 for strong general-purpose default or coding and software engineering. 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, Muse Spark 1.1 is the value pick.
GPT-5.4 (OpenAI) and Muse Spark 1.1 (Meta) are two of the models people most often weigh against each other in 2026. GPT-5.4 is openAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. 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
Price: Muse Spark 1.1 is about 2× cheaper on input ($1.25/$4.25 per 1M tokens vs $2.5/$15 per 1M tokens) — meaningful once you are processing millions of tokens a month.
Context window: 1M vs 1M — within a few percent of each other, so treat this as a tie and test on your own long inputs, since usable recall varies by model.
Recency: Muse Spark 1.1 is the newer model by about 4 months (released July 9, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
GPT-5.4
Muse Spark 1.1
Provider
OpenAI (US)
Meta (US)
Released
March 5, 2026
July 9, 2026
Context window
1M (~1,500 pages)
1M (~1,573 pages)
Price (in/out)
$2.5/$15 per 1M tokens
$1.25/$4.25 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, video, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
54.1%
Who wins what
Strong general-purpose default: GPT-5.4 — GPT-5.4 lists strong general-purpose default among its strengths; Muse Spark 1.1 does not.
Coding and software engineering: GPT-5.4 — 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
Document understanding and tool use: GPT-5.4 — GPT-5.4 lists document understanding and tool use among its strengths; Muse Spark 1.1 does not.
Scaled tool use — 88.1 on MCP Atlas, ahead of Opus 4.8 and GPT-5.5 (vendor-reported): Muse Spark 1.1 — At $1.25/$4.25 per 1M tokens it undercuts GPT-5.4 ($2.5/$15 per 1M tokens), and that gap compounds at volume.
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 runs cheaper at $1.25/$4.25 per 1M tokens.
Professional agentic work — 54.7 on JobBench, a wide margin over rivals (vendor-reported): Muse Spark 1.1 — GPT-5.4 is comparatively weak here — pricier than open-weight rivals
Lowest cost at scale: Muse Spark 1.1 — At $1.25/$4.25 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume: Muse Spark 1.1 — At $1.25/$4.25 per 1M tokens it undercuts GPT-5.4, 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 strong general-purpose default: GPT-5.4 — 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: where it fits
OpenAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. Released March 5, 2026 by OpenAI, it is built for strong general-purpose default, coding and software engineering, document understanding and tool use, and 1M context with good token efficiency.
Its trade-offs are real: topped by GPT-5.5 on the hardest tasks, and pricier than open-weight rivals. At $2.5 in / $15 out per million tokens, it sits in the mid 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 and Muse Spark 1.1 overlap enough that the right pick depends on your specific job. Muse Spark 1.1 costs less per token; Muse Spark 1.1 holds the larger context; and each leads in its own area — GPT-5.4 for strong general-purpose default, 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.
Frequently asked questions
Is GPT-5.4 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 leans toward strong general-purpose default 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 or Muse Spark 1.1?
Muse Spark 1.1 is cheaper — $2.5/$15 per 1M tokens vs $1.25/$4.25 per 1M tokens, roughly 2× apart on input.
Which has the bigger context window?
Effectively neither — 1M vs 1M is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both GPT-5.4 and Muse Spark 1.1 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.4, 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 or Muse Spark 1.1?
Muse Spark 1.1 — released July 9, 2026, about 4 months after GPT-5.4.
GPT-5.4 vs Muse Spark 1.1
OpenAI · US | Meta · US · Updated June 2026
Quick verdict
Pick GPT-5.4 for strong general-purpose default or coding and software engineering. 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, Muse Spark 1.1 is the value pick.
GPT-5.4 (OpenAI) and Muse Spark 1.1 (Meta) are two of the models people most often weigh against each other in 2026. GPT-5.4 is openAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. 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
▸Price: Muse Spark 1.1 is about 2× cheaper on input ($1.25/$4.25 per 1M tokens vs $2.5/$15 per 1M tokens) — meaningful once you are processing millions of tokens a month.
▸Context window: 1M vs 1M — within a few percent of each other, so treat this as a tie and test on your own long inputs, since usable recall varies by model.
▸Recency: Muse Spark 1.1 is the newer model by about 4 months (released July 9, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
GPT-5.4
Muse Spark 1.1
Provider
OpenAI (US)
Meta (US)
Released
March 5, 2026
July 9, 2026
Context window
1M (~1,500 pages)
1M (~1,573 pages)
Price (in/out)
$2.5/$15 per 1M tokens
$1.25/$4.25 per 1M tokens
Open weight?
No — API only
No — API only
Modalities
text, image, code
text, image, video, code
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
54.1%
Who wins what
Strong general-purpose default
GPT-5.4
GPT-5.4 lists strong general-purpose default among its strengths; Muse Spark 1.1 does not.
Coding and software engineering
GPT-5.4
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
Document understanding and tool use
GPT-5.4
GPT-5.4 lists document understanding and tool use among its strengths; Muse Spark 1.1 does not.
Scaled tool use — 88.1 on MCP Atlas, ahead of Opus 4.8 and GPT-5.5 (vendor-reported)
Muse Spark 1.1
At $1.25/$4.25 per 1M tokens it undercuts GPT-5.4 ($2.5/$15 per 1M tokens), and that gap compounds at volume.
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 runs cheaper at $1.25/$4.25 per 1M tokens.
Professional agentic work — 54.7 on JobBench, a wide margin over rivals (vendor-reported)
Muse Spark 1.1
GPT-5.4 is comparatively weak here — pricier than open-weight rivals
Lowest cost at scale
Muse Spark 1.1
At $1.25/$4.25 per 1M tokens, it is the cheaper of the two — the gap dominates the bill on high-volume workloads.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Muse Spark 1.1
At $1.25/$4.25 per 1M tokens it undercuts GPT-5.4, 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 strong general-purpose default
→ GPT-5.4
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: where it fits
OpenAI's 2026 workhorse — unifies Codex and GPT into a strong default that costs half of GPT-5.5. Released March 5, 2026 by OpenAI, it is built for strong general-purpose default, coding and software engineering, document understanding and tool use, and 1M context with good token efficiency.
Its trade-offs are real: topped by GPT-5.5 on the hardest tasks, and pricier than open-weight rivals. At $2.5 in / $15 out per million tokens, it sits in the mid 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 and Muse Spark 1.1 overlap enough that the right pick depends on your specific job. Muse Spark 1.1 costs less per token; Muse Spark 1.1 holds the larger context; and each leads in its own area — GPT-5.4 for strong general-purpose default, 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 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.
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 leans toward strong general-purpose default 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 or Muse Spark 1.1?
Muse Spark 1.1 is cheaper — $2.5/$15 per 1M tokens vs $1.25/$4.25 per 1M tokens, roughly 2× apart on input.
Which has the bigger context window?
Effectively neither — 1M vs 1M is a difference of a few percent. Remember advertised ≠ usable: recall typically degrades before the ceiling.
Can I use both GPT-5.4 and Muse Spark 1.1 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.4, 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 or Muse Spark 1.1?
Muse Spark 1.1 — released July 9, 2026, about 4 months after GPT-5.4.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.