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GPT-5.6 Sol vs Grok 4.5

Updated October 21, 2026. 119 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace GPT-5.6 Sol Replace Grok 4.5
GPT-5.6 SolOpenAI
Coding
76.7
Overall
47.0
Output $/M
$20.00
101
Grok 4.5xAI
Coding
75.5
Overall
38.8
Output $/M
$6.00
18
vs boards won of 119 shared

Decision reading

GPT-5.6 Sol and Grok 4.5 are level for coding, 76.7 against 75.5 on the Vibe Coding Index, so price and context decide.

Pick Grok 4.5 when output tokens cost 3.3x less, or when a solved task costs $0.62 against $1.20. Pick GPT-5.6 Sol when the context window is larger, 1.05M against 500K tokens, or when what matters is LMArena WebDev or AA Coding Index, where it leads.

Model AGPT-5.6 SolOpenAI76.7/1002 independent benchmarks$1.20 per solved taskModel BGrok 4.5xAI75.5/1002 independent benchmarks$0.62 per solved task
Shared results
119
GPT-5.6 Sol only
17
Grok 4.5 only
1
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
GPT-5.6 Sol 76.7 from 2 benchmarks, Grok 4.5 75.5 from 2 benchmarks.
Widest category
Math, 24.9 points apart on average over 6 shared benchmarks.
Widest single gap
FrontierMath, tier 4: GPT-5.6 Sol 82.9% against Grok 4.5 24.4%, 58.5 points apart on a 0 to 100 scale.
Output price
GPT-5.6 Sol $20.00 against Grok 4.5 $6.00 per million output tokens, 3.3x apart.
Context window
GPT-5.6 Sol takes 1.05M tokens, Grok 4.5 500K.

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
CategoryGPT-5.6 SolBarsGrok 4.5Ties
Coding193
Intelligence20
Agentic work201
Reasoning141
Math60
Knowledge74
Web design90
General249
All shared boards10118
CodingLike-for-likeFour of these boards feed the Vibe Coding Index193
Coding benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
LiveBench coding89.7%94.3%Grok 4.5
LMArena WebDev16161553GPT-5.6 Sol
AA Coding Index77.472.4GPT-5.6 Sol
LiveCodeBench (Vals AI)82.6%87.3%Grok 4.5
SWE-bench Verified (Vals AI)96.2%86.6%GPT-5.6 Sol
Terminal-Bench 4 (Vals AI)37.9%8.6%GPT-5.6 Sol
Vibe Code Bench (Vals AI)80.5%69.0%GPT-5.6 Sol
Code migration (Vals AI)52.9%36.6%GPT-5.6 Sol
ProgramBench (Vals AI)1.5%0.0%GPT-5.6 Sol
IOI (Vals AI)91.2%40.6%GPT-5.6 Sol
Terminal-Bench 2.1 (Vals AI)85.8%67.8%GPT-5.6 Sol
Vibe Code Bench 1-100 (Vals AI)20.0%Not measuredOnly GPT-5.6 Sol measured
SkillsBench (Vals AI)54.1%66.0%Grok 4.5
CyberBench (Vals AI)76.3%71.0%GPT-5.6 Sol
SciCode57.8%55.0%GPT-5.6 Sol
Terminal-Bench Hard (Artificial Analysis run)65.9%Not measuredOnly GPT-5.6 Sol measured
FrontierCode47.5%42.4%GPT-5.6 Sol
FrontierSWE32.2%Not measuredOnly GPT-5.6 Sol measured
GSO-Bench76.5%Not measuredOnly GPT-5.6 Sol measured
WeirdML88.8%46.4%GPT-5.6 Sol
MirrorCode20.0%Not measuredOnly GPT-5.6 Sol measured
ALE-Bench2176.91309.3GPT-5.6 Sol
LMArena Text: coding14961474GPT-5.6 Sol
LMArena Text: software and IT14891471GPT-5.6 Sol
LMArena WebDev: React16201556GPT-5.6 Sol
LMArena WebDev: HTML16181567GPT-5.6 Sol
LMArena WebDev: from an image16091562GPT-5.6 Sol
Neither model has a result on the other 11 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index20
Intelligence benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
AA Intelligence Index47.038.8GPT-5.6 Sol
Epoch Capabilities Index162.8154.1GPT-5.6 Sol
Agentic workLike-for-likePublic boards, shown as published, kept out of the index201
Agentic work benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
AA Agentic Index50.241.2GPT-5.6 Sol
Design Arena: agents building web apps12451217GPT-5.6 Sol
Design Arena: agents building full-stack apps12611249GPT-5.6 Sol
Design Arena: agents building mobile apps12491221GPT-5.6 Sol
Design Arena: agents building Android apps12461242GPT-5.6 Sol
Design Arena: agents building Godot games12601229GPT-5.6 Sol
Design Arena: agents building games12671235GPT-5.6 Sol
Design Arena: HTML slides12861204GPT-5.6 Sol
Design Arena: PowerPoint slides12401232GPT-5.6 Sol
LiveBench research54.5%85.9%Grok 4.5
LiveBench browser88.0%44.0%GPT-5.6 Sol
LiveBench long agentic48.5%27.9%GPT-5.6 Sol
SREBench (Vals AI)30.5%0.8%GPT-5.6 Sol
Finance Agent (Vals AI)53.8%48.4%GPT-5.6 Sol
Tax Agent Bench (Vals AI)31.1%24.9%GPT-5.6 Sol
Legal Research Bench (Vals AI)48.1%38.0%GPT-5.6 Sol
Excel Modeling Benchmark (Vals AI)72.3%52.9%GPT-5.6 Sol
BioMysteryBench (Vals AI)71.1%Not measuredOnly GPT-5.6 Sol measured
Terminal-Bench-Science (Vals AI)20.0%Not measuredOnly GPT-5.6 Sol measured
Vals Science Index41.5%Not measuredOnly GPT-5.6 Sol measured
Time Horizon Index (Vals AI)23.8%6.3%GPT-5.6 Sol
CUA-bench (Vals AI)8.3%Not measuredOnly GPT-5.6 Sol measured
τ²-Bench Telecom85.1%Not measuredOnly GPT-5.6 Sol measured
APEX-AgentsNot measured56.2%Only Grok 4.5 measured
OSWorld 2.027.3%Not measuredOnly GPT-5.6 Sol measured
BALROG60.0%Not measuredOnly GPT-5.6 Sol measured
PostTrainBench36.2%23.4%GPT-5.6 Sol
Vending-Bench 2$9,619$3,887GPT-5.6 Sol
LMArena Search12611216GPT-5.6 Sol
Neither model has a result on the other 10 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index141
Reasoning benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
GPQA Diamond95.2%92.9%GPT-5.6 Sol
LiveBench reasoning91.7%87.2%GPT-5.6 Sol
MysteryMechanism (Vals AI)33.3%Not measuredOnly GPT-5.6 Sol measured
MMMU Pro (Vals AI)88.8%61.8%GPT-5.6 Sol
GPQA Diamond (Artificial Analysis run)94.1%93.1%GPT-5.6 Sol
Humanity's Last Exam (Artificial Analysis run)49.5%42.7%GPT-5.6 Sol
GPQA Diamond (Epoch AI run)93.5%93.4%GPT-5.6 Sol
ARC-AGI97.5%87.2%GPT-5.6 Sol
ARC-AGI-292.5%52.6%GPT-5.6 Sol
SimpleBench64.8%70.0%Grok 4.5
Chess puzzles59.0%35.0%GPT-5.6 Sol
Mystery game puzzles58.0%Not measuredOnly GPT-5.6 Sol measured
EBR-bench44.8%Not measuredOnly GPT-5.6 Sol measured
LMArena Text: hard prompts14831462GPT-5.6 Sol
LMArena Text: expert15171465GPT-5.6 Sol
LMArena Text: hard prompts in English14771464GPT-5.6 Sol
LMArena Vision: diagrams13051304GPT-5.6 Sol
LMArena Vision: homework13051295GPT-5.6 Sol
Neither model has a result on the other 3 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index60
Math benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
OTIS Mock AIME100.0%97.8%GPT-5.6 Sol
FrontierMath, tiers 1 to 389.1%57.2%GPT-5.6 Sol
FrontierMath, tier 482.9%24.4%GPT-5.6 Sol
ProofBench83.0%31.0%GPT-5.6 Sol
LMArena Text: math14731460GPT-5.6 Sol
LMArena Text: mathematical work14961482GPT-5.6 Sol
Neither model has a result on the other 7 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index74
Knowledge benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
MMLU Pro89.1%89.2%Grok 4.5
LegalBench (Vals AI)87.0%86.0%GPT-5.6 Sol
CorpFin (Vals AI)64.4%67.4%Grok 4.5
TaxEval (Vals AI)74.8%71.7%GPT-5.6 Sol
MortgageTax (Vals AI)67.3%61.8%GPT-5.6 Sol
MedCode (Vals AI)44.0%43.3%GPT-5.6 Sol
SimpleQA Verified69.7%48.3%GPT-5.6 Sol
LMArena Text: science14551464Grok 4.5
LMArena Text: medicine and healthcare14311440Grok 4.5
LMArena Text: legal and government14761463GPT-5.6 Sol
LMArena Text: business and finance14571441GPT-5.6 Sol
Neither model has a result on the other 6 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index90
Web design benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
Design Arena: websites13211281GPT-5.6 Sol
Design Arena: UI components13381279GPT-5.6 Sol
Design Arena: game dev13681263GPT-5.6 Sol
Design Arena: data viz13231267GPT-5.6 Sol
Design Arena: 3D13851257GPT-5.6 Sol
Design Arena: all code categories13411276GPT-5.6 Sol
Design Arena: SVG13161215GPT-5.6 Sol
Design Arena: ASCII art13021257GPT-5.6 Sol
LiveBench design81.6%78.1%GPT-5.6 Sol
GeneralLike-for-likePublic boards, shown as published, kept out of the index249
General benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
LiveBench data analysis79.8%73.0%GPT-5.6 Sol
Public Benefits Bench (Vals AI)66.5%Not measuredOnly GPT-5.6 Sol measured
SAGE (Vals AI)52.6%35.0%GPT-5.6 Sol
MedScribe (Vals AI)85.2%86.9%Grok 4.5
Vals Multimodal Index72.6%63.4%GPT-5.6 Sol
IFBench72.7%Not measuredOnly GPT-5.6 Sol measured
Long context reasoning (AA-LCR)84.0%79.3%GPT-5.6 Sol
DTBench95.7%96.5%Grok 4.5
LMCA58.5%45.2%GPT-5.6 Sol
Surface Evolver Bench93.1%74.4%GPT-5.6 Sol
Furniture assembly56.7%22.5%GPT-5.6 Sol
LMArena Text14571448GPT-5.6 Sol
LMArena Text: instruction following14831445GPT-5.6 Sol
LMArena Text: creative writing14491442GPT-5.6 Sol
LMArena Vision12811287Grok 4.5
LMArena Text: English14571453GPT-5.6 Sol
LMArena Text: non-English14511440GPT-5.6 Sol
LMArena Text: Chinese15251495GPT-5.6 Sol
LMArena Text: German14761448GPT-5.6 Sol
LMArena Text: Japanese14721430GPT-5.6 Sol
LMArena Text: Korean14421406GPT-5.6 Sol
LMArena Text: French14721457GPT-5.6 Sol
LMArena Text: Spanish14431451Grok 4.5
LMArena Text: Russian14711449GPT-5.6 Sol
LMArena Text: Polish14591432GPT-5.6 Sol
LMArena Text: multi-turn14611456GPT-5.6 Sol
LMArena Text: longer queries14811462GPT-5.6 Sol
LMArena Text: writing and language14621445GPT-5.6 Sol
LMArena Text: entertainment and media14501434GPT-5.6 Sol
LMArena Vision: English12801285Grok 4.5
LMArena Vision: Chinese13131345Grok 4.5
LMArena Vision: reading text12901293Grok 4.5
LMArena Vision: humor12461276Grok 4.5
LMArena Vision: creative writing12831293Grok 4.5
LMArena Document14831452GPT-5.6 Sol
Neither model has a result on the other 11 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for GPT-5.6 Sol and Grok 4.5
BenchmarkGPT-5.6 SolGrok 4.5Leader
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

GPT-5.6 Sol$0.014Fits in one request
Grok 4.5$0.0050Fits in one request

Grok 4.5 costs less

Repository review

50K input + 3K output tokens

GPT-5.6 Sol$0.260Fits in one request
Grok 4.5$0.118Fits in one request

Grok 4.5 costs less

Agent loop

200K input + 10K output tokens

GPT-5.6 Sol$1.00Fits in one request
Grok 4.5$0.460Fits in one request

Grok 4.5 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 GPT-5.6 Sol and Grok 4.5
SpecificationOpenAI GPT-5.6 SolSpaceXAI Grok 4.5
MakerOpenAIxAI
WeightsNo public weights listedNo public weights listed
ReleasedJuly 9, 2026July 8, 2026
Context window1.05M500K
Input $/Mtok$4.00$2.00
Output $/Mtok$20.00$6.00
Coding index76.775.5
Independent measurements behind it22
Cost per solved task$1.20$0.62
SourceOpenRouter listingOpenRouter listing

Questions

Is GPT-5.6 Sol better than Grok 4.5 for coding?

GPT-5.6 Sol and Grok 4.5 are level for coding, 76.7 against 75.5 on the Vibe Coding Index, so price and context decide. Pick Grok 4.5 when output tokens cost 3.3x less, or when a solved task costs $0.62 against $1.20. Pick GPT-5.6 Sol when the context window is larger, 1.05M against 500K tokens, or when what matters is LMArena WebDev or AA Coding Index, where it leads.

Which is cheaper, GPT-5.6 Sol or Grok 4.5?

GPT-5.6 Sol costs $4.00 per million input tokens and $20.00 per million output tokens; Grok 4.5 costs $2.00 and $6.00. Per solved SWE-bench Verified task, GPT-5.6 Sol costs $1.20 and Grok 4.5 $0.62.

Which has the bigger context window, GPT-5.6 Sol or Grok 4.5?

GPT-5.6 Sol, with 1.05M tokens against 500K.

How many benchmarks is the GPT-5.6 Sol vs Grok 4.5 comparison based on?

119 benchmarks have a result for both models as of October 21, 2026. GPT-5.6 Sol's coding index rests on 2 independent benchmarks and Grok 4.5's on 2. Where only one model has a result, the page says so instead of naming a winner.

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