Model comparison

GPT-5.6 Sol vs Grok 4.3

Data verified July 23, 2026

Head-to-head evidence from 18 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

GPT-5.6 Sol

OpenAI

81.96/100

Margin

16.9pts

← winning

Grok 4.3

xAI

65.1/100

3 category wins0 category wins

Public leaderboard positions: GPT-5.6 Sol #3 (Supported); Grok 4.3 #31 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.6 Sol and Grok 4.3 share 18 comparable benchmark results. 3 of 8 categories are comparable. 28 results are unique to GPT-5.6 Sol; 7 to Grok 4.3.

Updated July 23, 2026

Shared results: 18
GPT-5.6 Sol only: 28
Grok 4.3 only: 7
Comparable categories: 3 / 8

Pick GPT-5.6 Sol if you want the stronger benchmark profile. Grok 4.3 only becomes the better choice if you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 18 shared benchmark results across 6 evidence categories; 3 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

GPT-5.6 Sol is clearly ahead on the BenchAlign aggregate, 81.96 to 65.1. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.6 Sol's sharpest advantage is in knowledge, where it averages 94.6 against 42.4. The single biggest benchmark swing on the page is MMMU-Pro, 83% to 78.1%.

GPT-5.6 Sol is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $1.25 input / $2.50 output per 1M tokens for Grok 4.3. That is roughly 12.0x on output cost alone.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for GPT-5.6 Sol and Grok 4.3
Category	GPT-5.6 Sol	Δ	Grok 4.3
Knowledge	GPT-5.6 Sol94.6	Margin← 52.2	Grok 4.342.4
Coding	GPT-5.6 Sol64.6	Margin← 17.3	Grok 4.347.3
Multimodal	GPT-5.6 Sol83.0	Margin← 4.9	Grok 4.378.1
Agentic	GPT-5.6 Sol92.0	MarginNo overlap	Grok 4.3Not measured
Math	GPT-5.6 Sol87.5	MarginNo overlap	Grok 4.3Not measured
Inst. Following	GPT-5.6 SolNot measured	MarginNo overlap	Grok 4.381.3

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

A · GPT-5.6 SolB · Grok 4.3

MMMU-Pro
Multimodal
Source ↗
A 83%B 78.1%
Winner: GPT-5.6 SolΔ 4.9
MMMU-Pro: GPT-5.6 Sol scored 83%; Grok 4.3 scored 78.1%. GPT-5.6 Sol wins this benchmark.
GPQA
Knowledge
Source ↗
A 94.6%B 90.1%
Winner: GPT-5.6 SolΔ 4.5
GPQA: GPT-5.6 Sol scored 94.6%; Grok 4.3 scored 90.1%. GPT-5.6 Sol wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

Metric	GPT-5.6 Sol	Grok 4.3	Comparison
Input / output priceUSD per 1M tokens	GPT-5.6 Sol$5 input / $30 output	Grok 4.3$1.25 input / $2.5 output	Grok 4.3 has the lower combined listed price.
Generation speedtokens per second	GPT-5.6 SolNot available	Grok 4.3209 tok/s	A complete speed comparison is not available.
First-answer latencyseconds to first token	GPT-5.6 SolNot available	Grok 4.312.36 s	A complete latency comparison is not available.
Context windowmaximum listed tokens	GPT-5.6 Sol1M	Grok 4.31M	Listed context windows are equal.

Benchmark Deep Dive

Agentic

20 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
Terminal-Bench 2.0Source	91.9%	—	Not comparable
BrowseCompSource	92.2%	—	Not comparable
OSWorld 2.0Source	62.6%	—	Not comparable
CyberGymSource	84.5%	—	Not comparable
ExploitGymSource	33.7%	—	Not comparable
ToolathlonSource	58%	—	Not comparable
AA Agentic IndexSource	54.0%	24.1%	GPT-5.6 Sol leads
τ²-bench resultsSource	85.1%	97.7%	Grok 4.3 leads
GDPval-AASource	61.8%	29.2%	GPT-5.6 Sol leads
GDPval-AASource	1736	1085	GPT-5.6 Sol leads
AA BriefcaseSource	1501	—	Not comparable
AA ITBenchSource	56.2%	—	Not comparable
AA Tau3 BankingSource	33.0%	—	Not comparable
AA AutomationBenchSource	51.2%	—	Not comparable
AA Harvey LABSource	87.2%	—	Not comparable
terminalBenchHardSource	65.9%	—	Not comparable
aaTerminalBench21Source	88%	—	Not comparable
APEX-Agents-AASource	—	17.0%	Not comparable
Gert LabsSource	—	43.86%	Not comparable
ResearchClawBenchSource	—	12.4%	Not comparable

CodingGPT-5.6 Sol wins

9 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
SWE-bench ProSource	64.6%	—	Not comparable
Terminal-Bench 2.0Source	91.9%	—	Not comparable
deepSweSource	72.7%	—	Not comparable
FrontierCode 1.1 ExtendedSource	60.6%	—	Not comparable
cursorBench32Source	67.2%	—	Not comparable
VulcanBench v3Source	87.0%	—	Not comparable
AA Coding IndexSource	77.4%	42.3%	GPT-5.6 Sol leads
AA-SciCodeSource	56.1%	47.3%	GPT-5.6 Sol leads
SciCodeSource	—	47.3%	Not comparable

Reasoning

4 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
ARC-AGI-3Source	7.8%	—	Not comparable
GeneBench-ProSource	28.7%	—	Not comparable
AA-LCRSource	73.7%	64.3%	GPT-5.6 Sol leads
CritPtSource	32.3%	8.0%	GPT-5.6 Sol leads

KnowledgeGPT-5.6 Sol wins

11 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
GPQASource	94.6%	90.1%	GPT-5.6 Sol leads
GPQA-DSource	94.6%	—	Not comparable
HealthBench ProfessionalSource	60.5%	—	Not comparable
HealthBench HardSource	33.1%	—	Not comparable
Artificial Analysis Intelligence IndexSource	58.9%	37.6%	GPT-5.6 Sol leads
AA-GPQA DiamondSource	94.1%	90.1%	GPT-5.6 Sol leads
AA-HLESource	47.2%	35.0%	GPT-5.6 Sol leads
AA-Omniscience IndexSource	21.7%	18.3%	GPT-5.6 Sol leads
AA-Omniscience AccuracySource	58.5%	34.6%	GPT-5.6 Sol leads
AA-Omniscience Hallucination RateSource	88.8%	25.0%	Grok 4.3 leads
HLESource	—	35%	Not comparable

Math

3 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
FrontierMath (legacy)Source	89%	—	Not comparable
FrontierMath v2 (Tiers 1-3)Source	89.000%	—	Not comparable
FrontierMath v2 (Tier 4)Source	83.000%	—	Not comparable

MultimodalGPT-5.6 Sol wins

4 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
MMMU-ProSource	83%	78.1%	GPT-5.6 Sol leads
MMMU-Pro w/ PythonSource	84.6%	—	Not comparable
AA-MMMU-ProSource	83.4%	78.1%	GPT-5.6 Sol leads
Design Arena WebsiteSource	—	1225	Not comparable

Inst. Following

2 benchmarks

Benchmark	GPT-5.6 Sol	Grok 4.3	Result
AA-IFBenchSource	72.7%	81.3%	Grok 4.3 leads
IFBenchSource	—	81.3%	Not comparable

Frequently Asked Questions (4)

Which is better, GPT-5.6 Sol or Grok 4.3?

GPT-5.6 Sol is ahead on BenchLM's BenchAlign leaderboard, 81.96 to 65.1. The biggest single separator in this matchup is MMMU-Pro, where the scores are 83% and 78.1%.

Which is better for knowledge tasks, GPT-5.6 Sol or Grok 4.3?

GPT-5.6 Sol has the edge for knowledge tasks in this comparison, averaging 94.6 versus 42.4. Inside this category, AA-Omniscience Hallucination Rate is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.6 Sol or Grok 4.3?

GPT-5.6 Sol has the edge for coding in this comparison, averaging 64.6 versus 47.3. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.6 Sol or Grok 4.3?

GPT-5.6 Sol has the edge for multimodal and grounded tasks in this comparison, averaging 83 versus 78.1. Inside this category, AA-MMMU-Pro is the benchmark that creates the most daylight between them.

Related Comparisons

Explore More

OpenAI Compare Pricing Methodology Find Your Best LLM Overall Rankings

Last updated: July 23, 2026

Choose a model with this week’s evidence

Join 2,000+ readers for ranking moves, pricing changes, and the claims that still need proof.

One email each week. Unsubscribe anytime.