Pick GPT-5.2 for strong all-round reasoning or reliable structured output. Pick Muse Spark 1.3 for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2 or deepswe v1.1 long-horizon software engineering (75.4). On a tight budget at scale, Muse Spark 1.3 is the value pick.
GPT-5.2 (OpenAI) and Muse Spark 1.3 (Meta) are two of the models people most often weigh against each other in 2026. GPT-5.2 is a capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Muse Spark 1.3 is meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences
Price: Muse Spark 1.3 is about 1.4× cheaper on input ($1.25/$4.25 per 1M tokens vs $1.75/$14 per 1M tokens) — modest, but it adds up at steady volume.
Context window: Muse Spark 1.3 holds 2.5× more — 1M tokens (~1,500 pages) vs 400K (~600 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
Recency: Muse Spark 1.3 is the newer model by about 9 months (released September 2, 2026), usually meaning fresher training data and capabilities.
Specifications
Spec
GPT-5.2
Muse Spark 1.3
Provider
OpenAI (US)
Meta (US)
Released
December 11, 2025
September 2, 2026
Context window
400K (~600 pages)
1M tokens (~1,500 pages)
Price (in/out)
$1.75/$14 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
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
98.1%
Who wins what
Strong all-round reasoning: GPT-5.2 — Muse Spark 1.3 is comparatively weak here — strongest 'max' reasoning configuration still gated pending additional safety testing
Reliable structured output: GPT-5.2 — GPT-5.2 lists reliable structured output among its strengths; Muse Spark 1.3 does not.
Broad ecosystem and tooling: GPT-5.2 — GPT-5.2 lists broad ecosystem and tooling among its strengths; Muse Spark 1.3 does not.
Agentic coding with ~20% fewer tool calls and ~25% fewer tokens than Muse Spark 1.2: Muse Spark 1.3 — Its 1M tokens window holds about 2.5× more than GPT-5.2's 400K in a single prompt.
DeepSWE v1.1 long-horizon software engineering (75.4): Muse Spark 1.3 — Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review — and it runs cheaper at $1.25/$4.25 per 1M tokens.
Near-perfect long-context retrieval (MRCR v2 512K-1M: 98.1): Muse Spark 1.3 — GPT-5.2 is comparatively weak here — smaller context than flagships
Lowest cost at scale: Muse Spark 1.3 — At $1.25/$4.25 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 1.3 — Its 1M tokens window is about 2.5× larger than GPT-5.2's 400K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume: Muse Spark 1.3 — At $1.25/$4.25 per 1M tokens it undercuts GPT-5.2, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases: Muse Spark 1.3 — Larger 1M tokens window fits more in one prompt.
Anyone whose priority is strong all-round reasoning: GPT-5.2 — It is specifically built for that.
Anyone whose priority is agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2: Muse Spark 1.3 — That is its strongest area.
GPT-5.2: where it fits
A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Released December 11, 2025 by OpenAI, it is built for strong all-round reasoning, reliable structured output, broad ecosystem and tooling, and professional workflows.
Its trade-offs are real: superseded by GPT-5.5, and smaller context than flagships. At $1.75 in / $14 out per million tokens, it sits in the mid price band.
Muse Spark 1.3: where it fits
Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review. Released September 2, 2026 by Meta, it is built for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than Muse Spark 1.2, deepSWE v1.1 long-horizon software engineering (75.4), near-perfect long-context retrieval (MRCR v2 512K-1M: 98.1), and ranks third overall on the Artificial Analysis Intelligence Index (score 61, xhigh variant; the limited-preview max variant scores 62) - behind only Claude Fable 5.1 and Claude Opus 5.
Its trade-offs: strongest 'max' reasoning configuration still gated pending additional safety testing, not yet open-weight, despite Meta roadmapping a future Muse Spark weights release, and no official SWE-bench Verified score published. At $1.25 in / $4.25 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
GPT-5.2 and Muse Spark 1.3 overlap enough that the right pick depends on your specific job. Muse Spark 1.3 costs less per token; Muse Spark 1.3 holds the larger context; and each leads in its own area — GPT-5.2 for strong all-round reasoning, Muse Spark 1.3 for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2. Rather than crowning one, run the same hard task through both once and let the results decide.
Frequently asked questions
Is GPT-5.2 or Muse Spark 1.3 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-5.2 leans toward strong all-round reasoning while Muse Spark 1.3 leans toward agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.2 or Muse Spark 1.3?
Muse Spark 1.3 is cheaper — $1.75/$14 per 1M tokens vs $1.25/$4.25 per 1M tokens, roughly 1.4× apart on input.
Which has the bigger context window?
Muse Spark 1.3 — 1M tokens vs 400K, about 2.5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.2 and Muse Spark 1.3 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.2, Muse Spark 1.3 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-5.2 or Muse Spark 1.3?
Muse Spark 1.3 — released September 2, 2026, about 9 months after GPT-5.2.
GPT-5.2 vs Muse Spark 1.3
OpenAI · US | Meta · US · Updated June 2026
Quick verdict
Pick GPT-5.2 for strong all-round reasoning or reliable structured output. Pick Muse Spark 1.3 for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2 or deepswe v1.1 long-horizon software engineering (75.4). On a tight budget at scale, Muse Spark 1.3 is the value pick.
GPT-5.2 (OpenAI) and Muse Spark 1.3 (Meta) are two of the models people most often weigh against each other in 2026. GPT-5.2 is a capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Muse Spark 1.3 is meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review. They diverge most on price and context window — each quantified below from the models' real specs.
Key differences at a glance
▸Price: Muse Spark 1.3 is about 1.4× cheaper on input ($1.25/$4.25 per 1M tokens vs $1.75/$14 per 1M tokens) — modest, but it adds up at steady volume.
▸Context window: Muse Spark 1.3 holds 2.5× more — 1M tokens (~1,500 pages) vs 400K (~600 pages). But effective recall usually fades long before the advertised ceiling, so the bigger number only helps if the model reasons over it.
▸Recency: Muse Spark 1.3 is the newer model by about 9 months (released September 2, 2026), usually meaning fresher training data and capabilities.
Side-by-side specs
Spec
GPT-5.2
Muse Spark 1.3
Provider
OpenAI (US)
Meta (US)
Released
December 11, 2025
September 2, 2026
Context window
400K (~600 pages)
1M tokens (~1,500 pages)
Price (in/out)
$1.75/$14 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
SWE-Bench Verified
Not published
Not published
MRCR v2 @ 1M
Not published
98.1%
Who wins what
Strong all-round reasoning
GPT-5.2
Muse Spark 1.3 is comparatively weak here — strongest 'max' reasoning configuration still gated pending additional safety testing
Reliable structured output
GPT-5.2
GPT-5.2 lists reliable structured output among its strengths; Muse Spark 1.3 does not.
Broad ecosystem and tooling
GPT-5.2
GPT-5.2 lists broad ecosystem and tooling among its strengths; Muse Spark 1.3 does not.
Agentic coding with ~20% fewer tool calls and ~25% fewer tokens than Muse Spark 1.2
Muse Spark 1.3
Its 1M tokens window holds about 2.5× more than GPT-5.2's 400K in a single prompt.
Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review — and it runs cheaper at $1.25/$4.25 per 1M tokens.
GPT-5.2 is comparatively weak here — smaller context than flagships
Lowest cost at scale
Muse Spark 1.3
At $1.25/$4.25 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 1.3
Its 1M tokens window is about 2.5× larger than GPT-5.2's 400K, fitting roughly 1,500 pages in one prompt.
Which should you pick?
A cost-sensitive startup shipping high volume
→ Muse Spark 1.3
At $1.25/$4.25 per 1M tokens it undercuts GPT-5.2, and on millions of tokens that margin decides the monthly bill.
Someone analysing very long documents or codebases
→ Muse Spark 1.3
Larger 1M tokens window fits more in one prompt.
Anyone whose priority is strong all-round reasoning
→ GPT-5.2
It is specifically built for that.
Anyone whose priority is agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2
→ Muse Spark 1.3
That is its strongest area.
GPT-5.2: where it fits
A capable GPT-5-generation all-rounder, now succeeded by GPT-5.5. Released December 11, 2025 by OpenAI, it is built for strong all-round reasoning, reliable structured output, broad ecosystem and tooling, and professional workflows.
Its trade-offs are real: superseded by GPT-5.5, and smaller context than flagships. At $1.75 in / $14 out per million tokens, it sits in the mid price band.
Muse Spark 1.3: where it fits
Meta's September 2, 2026 agentic-coding model update, cutting tool calls and token usage versus Muse Spark 1.2 while its highest-reasoning mode remains gated for safety review. Released September 2, 2026 by Meta, it is built for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than Muse Spark 1.2, deepSWE v1.1 long-horizon software engineering (75.4), near-perfect long-context retrieval (MRCR v2 512K-1M: 98.1), and ranks third overall on the Artificial Analysis Intelligence Index (score 61, xhigh variant; the limited-preview max variant scores 62) - behind only Claude Fable 5.1 and Claude Opus 5.
Its trade-offs: strongest 'max' reasoning configuration still gated pending additional safety testing, not yet open-weight, despite Meta roadmapping a future Muse Spark weights release, and no official SWE-bench Verified score published. At $1.25 in / $4.25 out per million tokens, it sits in the mid price band.
The bottom line for this matchup
GPT-5.2 and Muse Spark 1.3 overlap enough that the right pick depends on your specific job. Muse Spark 1.3 costs less per token; Muse Spark 1.3 holds the larger context; and each leads in its own area — GPT-5.2 for strong all-round reasoning, Muse Spark 1.3 for agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2. Rather than crowning one, run the same hard task through both once and let the results decide.
Want both GPT-5.2 and Muse Spark 1.3 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-5.2 leans toward strong all-round reasoning while Muse Spark 1.3 leans toward agentic coding with ~20% fewer tool calls and ~25% fewer tokens than muse spark 1.2, and that positioning usually predicts which feels better on your codebase.
Which is cheaper, GPT-5.2 or Muse Spark 1.3?
Muse Spark 1.3 is cheaper — $1.75/$14 per 1M tokens vs $1.25/$4.25 per 1M tokens, roughly 1.4× apart on input.
Which has the bigger context window?
Muse Spark 1.3 — 1M tokens vs 400K, about 2.5× larger. Useful only if the model actually reasons over the full window, which not all do.
Can I use both GPT-5.2 and Muse Spark 1.3 together?
Yes — a multi-model platform like LumiChats gives you GPT-5.2, Muse Spark 1.3 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-5.2 or Muse Spark 1.3?
Muse Spark 1.3 — released September 2, 2026, about 9 months after GPT-5.2.
Specifications and benchmarks reflect publicly reported figures as of June 2026 and may change as providers release updates. Always verify on your own workload.