Enter opens the highlighted result. Esc closes.

GPT-5.1 vs Grok 4.3

GPT-5.1 leads Grok 4.3 on coding, 40.4 to 37.4 on the Vibe Coding Index, and Grok 4.3 costs 4.0x less per output token ($2.50 vs $10.00 per million). Updated October 21, 2026; 79 benchmarks have a result for both.

Replace GPT-5.1 Replace Grok 4.3
GPT-5.1OpenAI
Coding
40.4
Overall
55.0
Output $/M
$10.00
61
Grok 4.3xAI
Coding
37.4
Overall
53.1
Output $/M
$2.50
18
vs boards won of 79 shared

GPT-5.1 or Grok 4.3: which to pick

Pick GPT-5.1 for coding: it scores 40.4 on the Vibe Coding Index against 37.4 for Grok 4.3.

Pick Grok 4.3 for output tokens 4.0x cheaper ($2.50 vs $10.00 per million) and a lower cost per solved task ($0.31 against $1.02).

Model AGPT-5.1OpenAI40.4/1003 independent benchmarks$1.02 per solved taskModel BGrok 4.3xAI37.4/1003 independent benchmarks$0.31 per solved task
Shared results
79
GPT-5.1 only
22
Grok 4.3 only
25
Like-for-like categories
8 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

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-5.1 40.4 from 3 benchmarks, Grok 4.3 37.4 from 3 benchmarks.
Widest category
Agentic work, 12.4 points apart on average over 2 shared benchmarks.
Widest single gap
Chess puzzles: GPT-5.1 42.0% against Grok 4.3 18.0%, 24.0 points apart on a 0 to 100 scale.
Output price
GPT-5.1 $10.00 against Grok 4.3 $2.50 per million output tokens, 4.0x apart.
Context window
GPT-5.1 takes 400K tokens, Grok 4.3 1M.

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-5.1BarsGrok 4.3Ties
Coding102
Intelligence01
Agentic work11
Reasoning74
Math21
Knowledge102
Web design35
General282
All shared boards6118
CodingLike-for-likeSix of these boards feed the Vibe Coding Index102
Coding benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
SWE-bench Verified66.0%Not measuredOnly GPT-5.1 measured
LMArena WebDev13961358GPT-5.1
AA Coding Index49.442.2GPT-5.1
LiveCodeBench (Vals AI)86.5%84.5%GPT-5.1
SWE-bench Verified (Vals AI)69.8%71.4%Grok 4.3
Vibe Code Bench (Vals AI)24.6%19.4%GPT-5.1
Code migration (Vals AI)Not measured6.8%Only Grok 4.3 measured
ProgramBench (Vals AI)Not measured0.0%Only Grok 4.3 measured
Terminal-Bench 2.1 (Vals AI)Not measured42.0%Only Grok 4.3 measured
SkillsBench (Vals AI)Not measured40.6%Only Grok 4.3 measured
LiveCodeBench (Artificial Analysis run)86.8%Not measuredOnly GPT-5.1 measured
SciCodeNot measured48.3%Only Grok 4.3 measured
Terminal-Bench Hard (Artificial Analysis run)45.5%37.9%GPT-5.1
Terminal-Bench47.6%Not measuredOnly GPT-5.1 measured
GSO-Bench13.7%Not measuredOnly GPT-5.1 measured
WeirdML60.8%49.9%GPT-5.1
ALE-BenchNot measured944.2Only Grok 4.3 measured
LMArena Text: coding14531415GPT-5.1
LMArena Text: software and IT14541416GPT-5.1
LMArena WebDev: React13071353Grok 4.3
LMArena WebDev: HTML14051367GPT-5.1
LMArena WebDev: from an image14211375GPT-5.1
Neither model has a result on the other 17 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
Intelligence benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
AA Intelligence Index24.724.9Grok 4.3
Epoch Capabilities Index149.8Not measuredOnly GPT-5.1 measured
Agentic workLike-for-likePublic boards, shown as published, kept out of the index11
Agentic work benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
AA Agentic IndexNot measured15.5Only Grok 4.3 measured
Design Arena: agents building web appsNot measured1126Only Grok 4.3 measured
Design Arena: agents building full-stack appsNot measured1006Only Grok 4.3 measured
Design Arena: agents building mobile appsNot measured1059Only Grok 4.3 measured
Design Arena: agents building Android appsNot measured961Only Grok 4.3 measured
Design Arena: agents building Godot gamesNot measured914Only Grok 4.3 measured
Design Arena: agents building gamesNot measured1007Only Grok 4.3 measured
Design Arena: HTML slidesNot measured1008Only Grok 4.3 measured
Design Arena: PowerPoint slidesNot measured1013Only Grok 4.3 measured
Finance Agent (Vals AI)Not measured37.7%Only Grok 4.3 measured
Tax Agent Bench (Vals AI)Not measured6.2%Only Grok 4.3 measured
Legal Research Bench (Vals AI)Not measured15.4%Only Grok 4.3 measured
Excel Modeling Benchmark (Vals AI)Not measured18.4%Only Grok 4.3 measured
τ²-Bench Telecom81.9%97.7%Grok 4.3
DeepResearch Bench42.8%Not measuredOnly GPT-5.1 measured
Vending-Bench 2$1,473$35GPT-5.1
LMArena SearchNot measured1166Only Grok 4.3 measured
Neither model has a result on the other 24 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index74
Reasoning benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
GPQA Diamond86.6%91.4%Grok 4.3
MMMU Pro (Vals AI)83.2%83.1%GPT-5.1
GPQA Diamond (Artificial Analysis run)87.3%90.1%Grok 4.3
Humanity's Last Exam (Artificial Analysis run)28.5%37.2%Grok 4.3
GPQA Diamond (Epoch AI run)87.6%88.8%Grok 4.3
ARC-AGI72.8%Not measuredOnly GPT-5.1 measured
ARC-AGI-217.6%Not measuredOnly GPT-5.1 measured
SimpleBench53.2%Not measuredOnly GPT-5.1 measured
Chess puzzles42.0%18.0%GPT-5.1
Mystery game puzzles19.0%Not measuredOnly GPT-5.1 measured
VPCT58.7%Not measuredOnly GPT-5.1 measured
LMArena Text: hard prompts14571396GPT-5.1
LMArena Text: expert14701384GPT-5.1
LMArena Text: hard prompts in English14621402GPT-5.1
LMArena Vision: diagrams12641241GPT-5.1
LMArena Vision: homework12721241GPT-5.1
Neither model has a result on the other 6 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index21
Math benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
AIME93.3%Not measuredOnly GPT-5.1 measured
MGSM (Vals AI)93.0%Not measuredOnly GPT-5.1 measured
AA Math Index94.0Not measuredOnly GPT-5.1 measured
AIME 2025 (Artificial Analysis run)94.0%Not measuredOnly GPT-5.1 measured
OTIS Mock AIME88.6%93.3%Grok 4.3
FrontierMath, tiers 1 to 3Not measured42.8%Only Grok 4.3 measured
FrontierMath, tier 4Not measured14.6%Only Grok 4.3 measured
ProofBenchNot measured11.0%Only Grok 4.3 measured
LMArena Text: math14461387GPT-5.1
LMArena Text: mathematical work14491396GPT-5.1
Neither model has a result on the other 3 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index102
Knowledge benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
MMLU Pro86.4%85.8%GPT-5.1
LegalBench (Vals AI)85.7%84.5%GPT-5.1
CaseLaw (Vals AI)73.4%79.3%Grok 4.3
CorpFin (Vals AI)63.8%68.5%Grok 4.3
TaxEval (Vals AI)74.9%70.8%GPT-5.1
MortgageTax (Vals AI)61.4%48.3%GPT-5.1
MedQA (Vals AI)96.4%Not measuredOnly GPT-5.1 measured
MedCode (Vals AI)52.7%38.1%GPT-5.1
MMLU Pro (Artificial Analysis run)87.0%Not measuredOnly GPT-5.1 measured
SimpleQA Verified48.0%33.2%GPT-5.1
LMArena Text: science14591399GPT-5.1
LMArena Text: medicine and healthcare14561384GPT-5.1
LMArena Text: legal and government14591386GPT-5.1
LMArena Text: business and finance14311381GPT-5.1
FACTS Benchmark Suite45.0%Not measuredOnly GPT-5.1 measured
Neither model has a result on the other 3 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index35
Web design benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
Design Arena: websites11871196Grok 4.3
Design Arena: UI components11661192Grok 4.3
Design Arena: game dev11791174GPT-5.1
Design Arena: data viz12041179GPT-5.1
Design Arena: 3D10611125Grok 4.3
Design Arena: all code categories11711187Grok 4.3
Design Arena: SVG11491081GPT-5.1
Design Arena: ASCII art11191125Grok 4.3
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index282
General benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
Public Benefits Bench (Vals AI)Not measured51.7%Only Grok 4.3 measured
SAGE (Vals AI)43.2%19.7%GPT-5.1
MedScribe (Vals AI)88.1%74.4%GPT-5.1
Vals Multimodal IndexNot measured43.3%Only Grok 4.3 measured
IFBench72.9%83.3%Grok 4.3
Long context reasoning (AA-LCR)80.0%75.0%GPT-5.1
DTBench90.1%90.7%Grok 4.3
LMCA43.9%38.3%GPT-5.1
CL-bench23.7%Not measuredOnly GPT-5.1 measured
CL-bench Life17.3%Not measuredOnly GPT-5.1 measured
LMArena Text14431397GPT-5.1
LMArena Text: instruction following14431366GPT-5.1
LMArena Text: creative writing14271380GPT-5.1
LMArena Vision12501229GPT-5.1
LMArena Text: English14511404GPT-5.1
LMArena Text: non-English14311385GPT-5.1
LMArena Text: Chinese14951422GPT-5.1
LMArena Text: German14381395GPT-5.1
LMArena Text: Japanese14531379GPT-5.1
LMArena Text: Korean14011354GPT-5.1
LMArena Text: French14501411GPT-5.1
LMArena Text: Spanish14331399GPT-5.1
LMArena Text: Russian14351399GPT-5.1
LMArena Text: Polish14401398GPT-5.1
LMArena Text: multi-turn14501406GPT-5.1
LMArena Text: longer queries14481393GPT-5.1
LMArena Text: writing and language14281385GPT-5.1
LMArena Text: entertainment and media14151370GPT-5.1
LMArena Vision: English12521235GPT-5.1
LMArena Vision: Chinese12701257GPT-5.1
LMArena Vision: reading text12551235GPT-5.1
LMArena Vision: humor12631222GPT-5.1
LMArena Vision: captioning1252Not measuredOnly GPT-5.1 measured
LMArena Vision: recognizing things12321217GPT-5.1
LMArena Vision: creative writing12661237GPT-5.1
LMArena Document1403Not measuredOnly GPT-5.1 measured
Neither model has a result on the other 10 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for GPT-5.1 and Grok 4.3
BenchmarkGPT-5.1Grok 4.3Leader
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-5.1$0.0063Fits in one request
Grok 4.3$0.0025Fits in one request

Grok 4.3 costs less

Repository review

50K input + 3K output tokens

GPT-5.1$0.092Fits in one request
Grok 4.3$0.070Fits in one request

Grok 4.3 costs less

Agent loop

200K input + 10K output tokens

GPT-5.1$0.350Fits in one request
Grok 4.3$0.275Fits in one request

Grok 4.3 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-5.1 and Grok 4.3
SpecificationOpenAI GPT-5.1SpaceXAI Grok 4.3
MakerOpenAIxAI
WeightsNo public weights listedNo public weights listed
ReleasedNovember 13, 2025April 30, 2026
Context window400K1M
Input $/Mtok$1.25$1.25
Output $/Mtok$10.00$2.50
Coding index40.437.4
Independent measurements behind it33
Cost per solved task$1.02$0.31
SourceOpenRouter listingOpenRouter listing

Questions

Is GPT-5.1 better than Grok 4.3 for coding?

Pick GPT-5.1 for coding: it scores 40.4 on the Vibe Coding Index against 37.4 for Grok 4.3. Pick Grok 4.3 for output tokens 4.0x cheaper ($2.50 vs $10.00 per million) and a lower cost per solved task ($0.31 against $1.02).

Which is cheaper, GPT-5.1 or Grok 4.3?

GPT-5.1 costs $1.25 per million input tokens and $10.00 per million output tokens; Grok 4.3 costs $1.25 and $2.50. Per solved SWE-bench Verified task, GPT-5.1 costs $1.02 and Grok 4.3 $0.31.

Which has the bigger context window, GPT-5.1 or Grok 4.3?

Grok 4.3, with 1M tokens against 400K.

How many benchmarks is the GPT-5.1 vs Grok 4.3 comparison based on?

79 benchmarks have a result for both models as of October 21, 2026. GPT-5.1's coding index rests on 3 independent benchmarks and Grok 4.3's on 3. Where only one model has a result, the page says so instead of naming a winner.

Compare next

Embed this comparison on your site

Free under CC BY 4.0, while the source link stays visible. Preview the frame · Terms and other embeds

<iframe src="https://llmbenchmark.ai/embed/compare/gpt-5-1-vs-grok-4-3" title="GPT-5.1 vs Grok 4.3, LLMBenchmark.ai" width="100%" height="360" style="border:0;max-width:100%" loading="lazy"></iframe>
<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/gpt-5-1-vs-grok-4-3">LLMBenchmark.ai, GPT-5.1 vs Grok 4.3</a></p>