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GPT-5.4 mini vs Muse Spark 1.2

Decision reading

Muse Spark 1.2 has the higher public score estimate, 70.28 versus 61.05, but the 90% score intervals overlap. Treat that as a lead, not a settled winner.

3 results are shared. Category rows resting on Estimated evidence or different benchmark sets are marked directional and do not name a winner.

OpenAI logo
Model A
GPT-5.4 mini

OpenAI

61.05/100

Supported · Public rank #59

90% interval 50.871.3

Meta logo
Model B
Muse Spark 1.2

Meta

70.28/100

Estimated · Public rank #16

90% interval 58.976.0

Updated September 18, 2026. Rank says Muse Spark 1.2 is ahead. Price, access, and your workload can each overturn that. Public scores include evidence status and uncertainty.

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Which one for your work

Recommendations appear only when a shared evidence basis or an explicit operating constraint supports the call. Secondary and unsupported use cases stay disclosed below the initial list.

  • Coding work

    Code generation, repair, and software-engineering tasks

    Muse Spark 1.2

    Muse Spark 1.2 leads on the public coding lane, 60 to 42.6, with Supported evidence for both models, although the 90% intervals overlap.

    Confidence: limited

  • Long documents

    Prompts that approach the documented context limit

    Muse Spark 1.2

    Muse Spark 1.2 has the larger documented context window.

    Confidence: documented

  • Chat turn cost

    1K fresh input + 500 output tokens

    GPT-5.4 mini

    GPT-5.4 mini has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

Show secondary and unsupported calls
  • Cache-heavy agent loop cost

    200K cached + 20K fresh input + 10K output tokens

    GPT-5.4 mini

    GPT-5.4 mini has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Repository review cost

    50K fresh input + 3K output tokens

    GPT-5.4 mini

    GPT-5.4 mini has the lower estimated token cost for this stated workload. Costs use the listed standard API rates.

    Confidence: listed-rates

  • Agentic work

    Tool use, computer use, and multi-step task completion

    Not enough matched evidence

    GPT-5.4 mini is scored on Estimated evidence for agentic, so the reading is directional rather than like-for-like.

    Confidence: limited

Which one for a specific job

Choose a job from the LLM Selector's task catalog to see the category row it rests on, under the same basis rules as the table below. A directional row stays directional; choosing a job never creates a winner.

The same task catalog as the LLM Selector. Each job names the evidence surface it rests on; nothing here adds a new score.

42.6GPT-5.4 mini60.0Muse Spark 1.2

Like-for-like · BenchAlign

Muse Spark 1.2 leads the like-for-like coding row, although the 90% intervals overlap.

Coding scores combine specific tasks and setups. Match the editor, harness, and effort to your workflow.

What is actually comparable

Shared results can support a head-to-head reading. Results present for only one model describe coverage, not superiority.

Shared results
3
GPT-5.4 mini only
16
Muse Spark 1.2 only
5
Like-for-like categories
1 / 8

2 categories rest on Estimated evidence or different evidence sets. Those rows remain visible for coverage context but do not name a winner.

Category results, on a stated basis

Each row shows the public-lane category score for both models: the BenchAlign lane for agentic, coding, and knowledge, and the weighted public rows elsewhere, with the same rank each model page reports. A row is like-for-like only when both scores rest on Supported evidence or the same weighted set. Directional and not-comparable rows remain visible, but they never receive a winner.

Coding

Like-for-like
GPT-5.4 mini
42.6
Supported · #106/154
Muse Spark 1.2
60.0
Supported · #21/154
Basis
BenchAlign lane · 4 vs 5 public rows
Reading
Muse Spark 1.2 leads · intervals overlap

Agentic

Directional only
GPT-5.4 mini
39.1
Estimated · #124/154
Muse Spark 1.2
61.0
Supported · #16/154
Basis
BenchAlign lane · 6 vs 2 public rows
Reading
Directional only

Knowledge

Directional only
GPT-5.4 mini
55.6
Supported · #52/184
Muse Spark 1.2
70.7
Estimated · #10/184
Basis
BenchAlign lane · 5 vs 1 public rows
Reading
Directional only

Reasoning

Not comparable
GPT-5.4 mini
73.9
Unranked · 2 rankable rows
Muse Spark 1.2
75.3
Unranked · 2 rankable rows
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Math

Not comparable
GPT-5.4 mini
44.3
Unranked · 2 rankable rows
Muse Spark 1.2
Not ranked
Basis
Provisional lane · 2 vs 0 weighted rows
Reading
Not comparable

Multilingual

Not comparable
GPT-5.4 mini
Not ranked
Muse Spark 1.2
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Multimodal

Not comparable
GPT-5.4 mini
57.3
#31/48
Muse Spark 1.2
Not ranked
Basis
Provisional lane · 1 vs 0 weighted rows
Reading
Not comparable

Instruction following

Not comparable
GPT-5.4 mini
88.5
#24/124
Muse Spark 1.2
Not ranked
Basis
Provisional lane · 0 vs 0 weighted rows
Reading
Not comparable

Ranks count the models scored in each category’s lane, so the agentic, coding, and knowledge denominators (BenchAlign) differ from the provisional-lane categories. Unranked scores sit on the lane’s scale but never name a winner. Like-for-like rows within 0.5 points read as a practical tie.

Shape of the matched evidence

Only shared public evidence is shown. Sparse evidence stays a ruled list rather than being closed into a radar shape.

Too few matched category axes support a radar. The ruled list below shows only shared benchmark results; positions use each benchmark’s normalized display scale when available.

What each workload costs

Three fixed token mixes turn per-token rates into comparable decisions. Each scenario states context fit and whether cached input had to fall back to the published list-input rate.

Chat turn

1K fresh input + 500 output tokens

GPT-5.4 mini
$0.003
Fits in one request
Muse Spark 1.2
$0.00338
Fits in one request

GPT-5.4 mini has the lower modeled cost

Costs use the listed standard API rates.

Repository review

50K fresh input + 3K output tokens

GPT-5.4 mini
$0.051
Fits in one request
Muse Spark 1.2
$0.07525
Fits in one request

GPT-5.4 mini has the lower modeled cost

Costs use the listed standard API rates.

Cache-heavy agent loop

200K cached + 20K fresh input + 10K output tokens

GPT-5.4 mini
$0.075
Fits in one request
Muse Spark 1.2
$0.0975
Fits in one request

GPT-5.4 mini has the lower modeled cost

Costs use the listed standard API rates.

Specification differences

Sourced differences are shown directly. Missing facts stay explicit instead of being inferred from a model name or family.

Cached-input rate

A missing cached-input rate falls back to the listed input rate only in the stated workload estimate.

GPT-5.4 mini

$0.075 per 1M cached input tokens

OpenAI pricing

Muse Spark 1.2

$0.15 per 1M cached input tokens

Meta: Muse Spark 1.2 model page

Provider availability

GPT-5.4 mini

Generally Available · OpenAI Responses API

OpenAI model catalog

Muse Spark 1.2

Not sourced

Reasoning profile

GPT-5.4 mini

Reasoning

Muse Spark 1.2

Reasoning

Weight access

GPT-5.4 mini

Proprietary

Muse Spark 1.2

Proprietary

License

GPT-5.4 mini

Proprietary

Muse Spark 1.2

Proprietary

Release date

GPT-5.4 mini

2026-03-17

Muse Spark 1.2

2026-08-05

If you already use one of these models
Deployment change
The models list different providers, so authentication, endpoint behavior, limits, and feature support may change.
Quality signal
Muse Spark 1.2 has the higher public score estimate, 70.28 versus 61.05, but the 90% score intervals overlap.
Workload cost
Repository review: $0.051 vs $0.07525. Cache-heavy agent loop: $0.075 vs $0.0975.
Context tradeoff
Muse Spark 1.2 has the larger documented window (1M).

Run the same representative tasks against both endpoints before changing production traffic.

Benchmark evidence

The full public result ledger is available for audit without forcing a wide desktop table onto a phone.

Browse raw public benchmark evidence24 rows

Agentic

  • Terminal-Bench 2.0

    GPT-5.4 mini60%
    Source
    Muse Spark 1.2

    Not directly comparable

  • OSWorld-Verified

    GPT-5.4 mini72.1%
    Source
    Muse Spark 1.2

    Not directly comparable

  • MCP Atlas

    GPT-5.4 mini57.7%
    Source
    Muse Spark 1.2

    Not directly comparable

  • Toolathlon

    GPT-5.4 mini42.9%
    Source
    Muse Spark 1.2

    Not directly comparable

  • τ²-bench results

    GPT-5.4 mini93.4%
    Source
    Muse Spark 1.2

    Not directly comparable

  • Terminal-Bench 2.1 (Vals)

    GPT-5.4 mini54.7%
    Source
    Muse Spark 1.269.7%
    Source

    Muse Spark 1.2 leads this result

  • Terminal-Bench 2.1

    GPT-5.4 mini
    Muse Spark 1.282.9%
    Source

    Not directly comparable

Coding

  • Vibe Code Bench

    GPT-5.4 mini47.97%
    Source
    Muse Spark 1.2

    Not directly comparable

  • FrontierCode 1.1 Main

    GPT-5.4 mini27.0%
    Source
    Muse Spark 1.2

    Not directly comparable

  • LiveCodeBench (Vals)

    GPT-5.4 mini81.5%
    Source
    Muse Spark 1.2

    Not directly comparable

  • SWE-bench (Vals)

    GPT-5.4 mini73.0%
    Source
    Muse Spark 1.286.6%
    Source

    Muse Spark 1.2 leads this result

  • Terminal-Bench 2.1

    GPT-5.4 mini
    Muse Spark 1.282.9%
    Source

    Not directly comparable

  • DeepSWE

    GPT-5.4 mini
    Muse Spark 1.259.3%
    Source

    Not directly comparable

  • VulcanBench v3

    GPT-5.4 mini
    Muse Spark 1.287.0%
    Source

    Not directly comparable

  • FrontierSWE v2

    GPT-5.4 mini
    Muse Spark 1.212.0%
    Source

    Not directly comparable

Knowledge

  • GPQA

    GPT-5.4 mini88%
    Source
    Muse Spark 1.2

    Not directly comparable

  • HLE

    GPT-5.4 mini41.5%
    Source
    Muse Spark 1.2

    Not directly comparable

  • HLE w/o tools

    GPT-5.4 mini28.2%
    Source
    Muse Spark 1.2

    Not directly comparable

  • GPQA Diamond (Vals)

    GPT-5.4 mini83.1%
    Source
    Muse Spark 1.2

    Not directly comparable

  • MMLU-Pro (Vals)

    GPT-5.4 mini84.6%
    Source
    Muse Spark 1.288.3%
    Source

    Muse Spark 1.2 leads this result

Math

  • FrontierMath v2 (Tiers 1-3)

    GPT-5.4 mini28.280%
    Source
    Muse Spark 1.2

    Not directly comparable

  • FrontierMath v2 (Tier 4)

    GPT-5.4 mini2.080%
    Source
    Muse Spark 1.2

    Not directly comparable

Multimodal

  • MMMU-Pro

    GPT-5.4 mini76.6%
    Source
    Muse Spark 1.2

    Not directly comparable

  • MMMU-Pro w/ Python

    GPT-5.4 mini78%
    Source
    Muse Spark 1.2

    Not directly comparable

Questions

Which is better, GPT-5.4 mini or Muse Spark 1.2?

Muse Spark 1.2 has the higher public score estimate, 70.28 versus 61.05, but the 90% score intervals overlap. The higher estimate is not a decisive winner because the uncertainty ranges overlap.

Which is better for coding, GPT-5.4 mini or Muse Spark 1.2?

Muse Spark 1.2 leads the public coding lane, 60 to 42.6, with Supported evidence for both models, although the 90% intervals overlap.

Which is better for agentic tasks, GPT-5.4 mini or Muse Spark 1.2?

Muse Spark 1.2 scores higher for agentic tasks on the public lane, 61 to 39.1. GPT-5.4 mini is scored on Estimated evidence for agentic tasks, so the reading is directional rather than like-for-like. BenchLM does not name a winner for agentic tasks from a directional reading; read the shared benchmark rows directly and test the models on the same task set.

Which costs less, GPT-5.4 mini or Muse Spark 1.2?

For the stated presets, chat costs $0.003 on GPT-5.4 mini and $0.00337 on Muse Spark 1.2; repository review costs $0.051 and $0.07525; the cache-heavy agent loop costs $0.075 and $0.0975. Costs use the listed standard API rates.

Which has the larger context window, GPT-5.4 mini or Muse Spark 1.2?

Muse Spark 1.2 has the larger documented context window: 1M, compared with 400K.

Related comparisons

Last updated September 18, 2026

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