Model comparison

GPT-5-Codex vs GPT-6 Sol

GPT-6 Sol is the stronger model overall, scoring 61.8 to 37.9 on the Noometry Index.

Last verified . 0 shared benchmarks.

GPT-5-Codex OpenAI

37.9

Rank #192 Reported

GPT-6 Sol OpenAI

61.8

Rank #12 Confirmed

Summary

  • The widest gap is in reasoning, where GPT-6 Sol leads 74.0 to 30.9.
  • GPT-5-Codex is cheaper at $1.25 / $10 per million input/output tokens, against $2 / $10 for GPT-6 Sol.
  • GPT-6 Sol accepts more context: 1.05M tokens versus 400K.

Side by side

GPT-5-Codex and GPT-6 Sol specifications
GPT-5-CodexGPT-6 Sol
ProviderOpenAIOpenAI
Noometry Index37.961.8
Released2025-09-152026-09-22
WeightsProprietaryProprietary
Context window400K1.05M
Max output128K128K
Input $ / M tokens$1.25$2
Output $ / M tokens$10$10
Results tracked345

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Category by category

Coding GPT-6 Sol leads

GPT-5-Codex: 42.4 (#103), GPT-6 Sol: 60.1 (#11)

Coding benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
DeepSWE—68.8%
FrontierCode—49.3%
LMArena WebDev—1688
SciCode—57.6%
WeirdML54.5%—
LMArena Coding—1447
ALE-Bench—2,462

Agentic & Tool Use GPT-6 Sol leads

GPT-5-Codex: 31.0 (#72), GPT-6 Sol: 37.2 (#36)

Agentic & Tool Use benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
Terminal-Bench44.3%—
APEX-Agents—54.3%
GDP.pdf—26.4%
Vending-Bench 2—14,428

Reasoning GPT-6 Sol leads

GPT-5-Codex: 30.9 (#83), GPT-6 Sol: 74.0 (#9)

Reasoning benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
ARC-AGI-2—89.6%
Kagi LLM Benchmark70.3%—
NYT Connections (extended)—90.1%
ARC-AGI-1—95.5%
CritPt—30.9%
EBR-Bench—53.3%
LMArena Hard Prompts—1418
Mystery Game Puzzles—56%
DTBench—97.3%
LMCA—59.1%
Epoch Capabilities Index—162.72

Math Not comparable

GPT-5-Codex: —, GPT-6 Sol: 87.2 (#7)

Math benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
FrontierMath (Tiers 1-3)—89.8%
FrontierMath Tier 4—90%
OTIS Mock AIME 2024-2025—100%
ProofBench—83%
LMArena Math—1402

Knowledge Not comparable

GPT-5-Codex: —, GPT-6 Sol: 64.8 (#15)

Knowledge benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
GPQA Diamond—94.3%
SimpleQA Verified—60.7%
Vectara Hallucination Rate—6.5%
LMArena Expert—1439

Multimodal Not comparable

GPT-5-Codex: —, GPT-6 Sol: 47.6 (#10)

Multimodal benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
LMArena Vision—1245
Blueprint-Bench 2—36.9%
Furniture Assembly—58.3%

Multilingual Not comparable

GPT-5-Codex: —, GPT-6 Sol: 50.5 (#118)

Multilingual benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
LMArena Non-English—1385
LMArena Chinese—1405
LMArena French—1410
LMArena German—1390
LMArena Japanese—1385
LMArena Korean—1341
LMArena Russian—1401
LMArena Spanish—1384

Instruction Following Not comparable

GPT-5-Codex: —, GPT-6 Sol: 74.5 (#94)

Instruction Following benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
LMArena Instruction Following—1412

Long Context Not comparable

GPT-5-Codex: —, GPT-6 Sol: 43.1 (#108)

Long Context benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
LMArena Longer Query—1411

Writing & Preference Not comparable

GPT-5-Codex: —, GPT-6 Sol: 71.9 (#18)

Writing & Preference benchmarks
BenchmarkGPT-5-CodexGPT-6 Sol
LMArena Text—1395
LMArena Creative Writing—1378
EQ-Bench Creative Writing—2125
LMArena Multi-Turn—1412

Frequently asked questions

Is GPT-5-Codex better than GPT-6 Sol?

GPT-6 Sol is the stronger model overall, scoring 61.8 to 37.9 on the Noometry Index.

Which is cheaper, GPT-5-Codex or GPT-6 Sol?

GPT-5-Codex is cheaper. It lists at $1.25 per million input tokens and $10 per million output tokens; GPT-6 Sol lists at $2 and $10.

Is GPT-5-Codex or GPT-6 Sol better for coding?

GPT-6 Sol scores higher on coding benchmarks: 60.1 versus 42.4 in the Noometry coding category.

Which has the bigger context window?

GPT-6 Sol does, with 1.05M tokens against 400K.

How many benchmarks do GPT-5-Codex and GPT-6 Sol share?

0 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and GPT-6 Sol has 45.

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