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Grok 4.5 vs Muse Spark 1.2

Updated October 21, 2026. 94 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace Grok 4.5 Replace Muse Spark 1.2
Grok 4.5xAI
Coding
75.5
Overall
38.8
Output $/M
$6.00
30
Muse Spark 1.2Meta
Coding
65.1
Overall
39.6
Output $/M
$4.25
63
vs boards won of 94 shared, 1 tied

Decision reading

Pick Grok 4.5 for coding: it scores 75.5 on the Vibe Coding Index against 65.1 for Muse Spark 1.2.

Pick Muse Spark 1.2 when output tokens cost 1.4x less, or when the context window is larger, 1.05M against 500K tokens.

Model AGrok 4.5xAI75.5/1002 independent benchmarks$0.62 per solved taskModel BMuse Spark 1.2Meta65.1/1002 independent benchmarks$0.64 per solved task
Shared results
94
Grok 4.5 only
26
Muse Spark 1.2 only
3
Like-for-like categories
8 of 9

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

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

At a glance

Coding index
Grok 4.5 75.5 from 2 benchmarks, Muse Spark 1.2 65.1 from 2 benchmarks.
Widest category
Agentic work, 6.4 points apart on average over 17 shared benchmarks.
Widest single gap
MMMU Pro (Vals AI): Grok 4.5 61.8% against Muse Spark 1.2 86.1%, 24.3 points apart on a 0 to 100 scale.
Output price
Grok 4.5 $6.00 against Muse Spark 1.2 $4.25 per million output tokens, 1.4x apart.
Context window
Grok 4.5 takes 500K tokens, Muse Spark 1.2 1.05M.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
CategoryGrok 4.5BarsMuse Spark 1.2Ties
Coding1071 tie
Intelligence02
Agentic work116
Reasoning28
Math12
Knowledge29
Web design18
General321
All shared boards30631 tie
CodingLike-for-likeFour of these boards feed the Vibe Coding Index107
Coding benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
LiveBench coding94.3%78.2%Grok 4.5
LMArena WebDev15531534Grok 4.5
AA Coding Index72.472.2Grok 4.5
LiveCodeBench (Vals AI)87.3%Not measuredOnly Grok 4.5 measured
SWE-bench Verified (Vals AI)86.6%86.6%Tie
Terminal-Bench 4 (Vals AI)8.6%6.1%Grok 4.5
Vibe Code Bench (Vals AI)69.0%79.1%Muse Spark 1.2
Code migration (Vals AI)36.6%29.9%Grok 4.5
ProgramBench (Vals AI)0.0%0.5%Muse Spark 1.2
IOI (Vals AI)40.6%21.8%Grok 4.5
Terminal-Bench 2.1 (Vals AI)67.8%69.7%Muse Spark 1.2
SkillsBench (Vals AI)66.0%53.0%Grok 4.5
CyberBench (Vals AI)71.0%69.5%Grok 4.5
SciCode55.0%57.4%Muse Spark 1.2
FrontierCode42.4%Not measuredOnly Grok 4.5 measured
FrontierSWENot measured12.0%Only Muse Spark 1.2 measured
WeirdML46.4%60.3%Muse Spark 1.2
ALE-Bench1309.3Not measuredOnly Grok 4.5 measured
LMArena Text: coding14741505Muse Spark 1.2
LMArena Text: software and IT14711505Muse Spark 1.2
LMArena WebDev: React15561526Grok 4.5
LMArena WebDev: HTML15671543Grok 4.5
LMArena WebDev: from an image1562Not measuredOnly Grok 4.5 measured
Neither model has a result on the other 15 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
Intelligence benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
AA Intelligence Index38.839.6Muse Spark 1.2
Epoch Capabilities Index154.1155.1Muse Spark 1.2
Agentic workLike-for-likePublic boards, shown as published, kept out of the index116
Agentic work benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
AA Agentic Index41.243.2Muse Spark 1.2
Design Arena: agents building web apps12171222Muse Spark 1.2
Design Arena: agents building full-stack apps12491210Grok 4.5
Design Arena: agents building mobile apps12211182Grok 4.5
Design Arena: agents building Android apps12421228Grok 4.5
Design Arena: agents building Godot games1229Not measuredOnly Grok 4.5 measured
Design Arena: agents building games12351179Grok 4.5
Design Arena: HTML slides12041135Grok 4.5
Design Arena: PowerPoint slides12321198Grok 4.5
LiveBench research85.9%67.7%Grok 4.5
LiveBench browser44.0%36.0%Grok 4.5
LiveBench long agentic27.9%21.3%Grok 4.5
SREBench (Vals AI)0.8%0.0%Grok 4.5
Finance Agent (Vals AI)48.4%60.6%Muse Spark 1.2
Tax Agent Bench (Vals AI)24.9%32.8%Muse Spark 1.2
Legal Research Bench (Vals AI)38.0%43.8%Muse Spark 1.2
Excel Modeling Benchmark (Vals AI)52.9%57.0%Muse Spark 1.2
BioMysteryBench (Vals AI)Not measured64.8%Only Muse Spark 1.2 measured
Time Horizon Index (Vals AI)6.3%Not measuredOnly Grok 4.5 measured
APEX-Agents56.2%45.4%Grok 4.5
PostTrainBench23.4%Not measuredOnly Grok 4.5 measured
Vending-Bench 2$3,887Not measuredOnly Grok 4.5 measured
LMArena Search1216Not measuredOnly Grok 4.5 measured
Neither model has a result on the other 16 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index28
Reasoning benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
GPQA Diamond92.9%Not measuredOnly Grok 4.5 measured
LiveBench reasoning87.2%90.0%Muse Spark 1.2
MMMU Pro (Vals AI)61.8%86.1%Muse Spark 1.2
GPQA Diamond (Artificial Analysis run)93.1%90.4%Grok 4.5
Humanity's Last Exam (Artificial Analysis run)42.7%45.5%Muse Spark 1.2
GPQA Diamond (Epoch AI run)93.4%Not measuredOnly Grok 4.5 measured
ARC-AGI87.2%Not measuredOnly Grok 4.5 measured
ARC-AGI-252.6%Not measuredOnly Grok 4.5 measured
SimpleBench70.0%74.5%Muse Spark 1.2
Chess puzzles35.0%27.0%Grok 4.5
LMArena Text: hard prompts14621489Muse Spark 1.2
LMArena Text: expert14651475Muse Spark 1.2
LMArena Text: hard prompts in English14641487Muse Spark 1.2
LMArena Vision: diagrams13041317Muse Spark 1.2
LMArena Vision: homework1295Not measuredOnly Grok 4.5 measured
Neither model has a result on the other 6 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index12
Math benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
OTIS Mock AIME97.8%Not measuredOnly Grok 4.5 measured
FrontierMath, tiers 1 to 357.2%Not measuredOnly Grok 4.5 measured
FrontierMath, tier 424.4%Not measuredOnly Grok 4.5 measured
ProofBench31.0%43.0%Muse Spark 1.2
LMArena Text: math14601484Muse Spark 1.2
LMArena Text: mathematical work14821480Grok 4.5
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index29
Knowledge benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
MMLU Pro89.2%88.3%Grok 4.5
LegalBench (Vals AI)86.0%85.3%Grok 4.5
CorpFin (Vals AI)67.4%70.9%Muse Spark 1.2
TaxEval (Vals AI)71.7%80.4%Muse Spark 1.2
MortgageTax (Vals AI)61.8%65.4%Muse Spark 1.2
MedCode (Vals AI)43.3%49.4%Muse Spark 1.2
SimpleQA Verified48.3%60.3%Muse Spark 1.2
LMArena Text: science14641500Muse Spark 1.2
LMArena Text: medicine and healthcare14401496Muse Spark 1.2
LMArena Text: legal and government14631517Muse Spark 1.2
LMArena Text: business and finance14411484Muse Spark 1.2
Neither model has a result on the other 6 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index18
Web design benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
Design Arena: websites12811313Muse Spark 1.2
Design Arena: UI components12791300Muse Spark 1.2
Design Arena: game dev12631302Muse Spark 1.2
Design Arena: data viz12671334Muse Spark 1.2
Design Arena: 3D12571301Muse Spark 1.2
Design Arena: all code categories12761313Muse Spark 1.2
Design Arena: SVG12151285Muse Spark 1.2
Design Arena: ASCII art12571284Muse Spark 1.2
LiveBench design78.1%67.1%Grok 4.5
GeneralLike-for-likePublic boards, shown as published, kept out of the index321
General benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
LiveBench data analysis73.0%76.5%Muse Spark 1.2
Public Benefits Bench (Vals AI)Not measured68.5%Only Muse Spark 1.2 measured
SAGE (Vals AI)35.0%47.7%Muse Spark 1.2
MedScribe (Vals AI)86.9%90.1%Muse Spark 1.2
Vals Multimodal Index63.4%69.8%Muse Spark 1.2
Long context reasoning (AA-LCR)79.3%79.0%Grok 4.5
DTBench96.5%94.7%Grok 4.5
LMCA45.2%48.4%Muse Spark 1.2
Surface Evolver Bench74.4%Not measuredOnly Grok 4.5 measured
Furniture assembly22.5%Not measuredOnly Grok 4.5 measured
LMArena Text14481482Muse Spark 1.2
LMArena Text: instruction following14451462Muse Spark 1.2
LMArena Text: creative writing14421436Grok 4.5
LMArena Vision12871304Muse Spark 1.2
LMArena Text: English14531483Muse Spark 1.2
LMArena Text: non-English14401476Muse Spark 1.2
LMArena Text: Chinese14951509Muse Spark 1.2
LMArena Text: German1448Not measuredOnly Grok 4.5 measured
LMArena Text: Japanese1430Not measuredOnly Grok 4.5 measured
LMArena Text: Korean14061462Muse Spark 1.2
LMArena Text: French14571495Muse Spark 1.2
LMArena Text: Spanish14511484Muse Spark 1.2
LMArena Text: Russian14491483Muse Spark 1.2
LMArena Text: Polish1432Not measuredOnly Grok 4.5 measured
LMArena Text: multi-turn14561502Muse Spark 1.2
LMArena Text: longer queries14621473Muse Spark 1.2
LMArena Text: writing and language14451453Muse Spark 1.2
LMArena Text: entertainment and media14341443Muse Spark 1.2
LMArena Vision: English12851291Muse Spark 1.2
LMArena Vision: Chinese1345Not measuredOnly Grok 4.5 measured
LMArena Vision: reading text12931313Muse Spark 1.2
LMArena Vision: humor1276Not measuredOnly Grok 4.5 measured
LMArena Vision: creative writing1293Not measuredOnly Grok 4.5 measured
LMArena Document1452Not measuredOnly Grok 4.5 measured
Neither model has a result on the other 12 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for Grok 4.5 and Muse Spark 1.2
BenchmarkGrok 4.5Muse Spark 1.2Leader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Grok 4.5$0.0050Fits in one request
Muse Spark 1.2$0.0034Fits in one request

Muse Spark 1.2 costs less

Repository review

50K input + 3K output tokens

Grok 4.5$0.118Fits in one request
Muse Spark 1.2$0.075Fits in one request

Muse Spark 1.2 costs less

Agent loop

200K input + 10K output tokens

Grok 4.5$0.460Fits in one request
Muse Spark 1.2$0.292Fits in one request

Muse Spark 1.2 costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Grok 4.5 and Muse Spark 1.2
SpecificationSpaceXAI Grok 4.5Meta Muse Spark 1.2
MakerxAIMeta
WeightsNo public weights listedNo public weights listed
ReleasedJuly 8, 2026August 5, 2026
Context window500K1.05M
Input $/Mtok$2.00$1.25
Output $/Mtok$6.00$4.25
Coding index75.565.1
Independent measurements behind it22
Cost per solved task$0.62$0.64
SourceOpenRouter listingOpenRouter listing

Questions

Is Grok 4.5 better than Muse Spark 1.2 for coding?

Pick Grok 4.5 for coding: it scores 75.5 on the Vibe Coding Index against 65.1 for Muse Spark 1.2. Pick Muse Spark 1.2 when output tokens cost 1.4x less, or when the context window is larger, 1.05M against 500K tokens.

Which is cheaper, Grok 4.5 or Muse Spark 1.2?

Grok 4.5 costs $2.00 per million input tokens and $6.00 per million output tokens; Muse Spark 1.2 costs $1.25 and $4.25. Per solved SWE-bench Verified task, Grok 4.5 costs $0.62 and Muse Spark 1.2 $0.64.

Which has the bigger context window, Grok 4.5 or Muse Spark 1.2?

Muse Spark 1.2, with 1.05M tokens against 500K.

How many benchmarks is the Grok 4.5 vs Muse Spark 1.2 comparison based on?

94 benchmarks have a result for both models as of October 21, 2026. Grok 4.5's coding index rests on 2 independent benchmarks and Muse Spark 1.2's on 2. Where only one model has a result, the page says so instead of naming a winner.

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<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/grok-4-5-vs-meta-muse-spark-1-2">LLMBenchmark.ai, Grok 4.5 vs Muse Spark 1.2</a></p>