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GPT-5.3-Codex vs GPT-6.1 Sol

Updated October 21, 2026. 18 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

GPT-5.3-CodexOpenAI
Coding
29.5
Overall
32.5
Output $/M
$14.00
0
GPT-6.1 SolOpenAI
Coding
88.7
Overall
51.8
Output $/M
$10.00
18
vs boards won of 18 shared

Decision reading

Pick GPT-6.1 Sol for coding: it scores 88.7 on the Vibe Coding Index against 29.5 for GPT-5.3-Codex.

GPT-5.3-Codex is neither cheaper nor larger in context, and leads no benchmark both models were measured on.

Shared results
18
GPT-5.3-Codex only
16
GPT-6.1 Sol only
77
Like-for-like categories
6 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-5.3-Codex 29.5 from 1 benchmark, GPT-6.1 Sol 88.7 from 2 benchmarks.
Widest category
Coding, 35.2 points apart on average over 7 shared benchmarks.
Widest single gap
Design Arena: 3D: GPT-5.3-Codex 1008 against GPT-6.1 Sol 1461, 56.6 points apart on a 0 to 100 scale.
Output price
GPT-5.3-Codex $14.00 against GPT-6.1 Sol $10.00 per million output tokens, 1.4x apart.
Context window
GPT-5.3-Codex takes 400K tokens, GPT-6.1 Sol 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
CategoryGPT-5.3-CodexBarsGPT-6.1 SolTies
Coding07
Intelligence02
Agentic work01
Reasoning01
Web design06
General01
All shared boards018
CodingLike-for-likeFour of these boards feed the Vibe Coding Index07
Coding benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
LiveBench codingNot measured96.0%Only GPT-6.1 Sol measured
LMArena WebDev14071753GPT-6.1 Sol
LiveCodeBench (Vals AI)87.3%Not measuredOnly GPT-5.3-Codex measured
SWE-bench Verified (Vals AI)78.0%Not measuredOnly GPT-5.3-Codex measured
Terminal-Bench 4 (Vals AI)Not measured55.0%Only GPT-6.1 Sol measured
Vibe Code Bench (Vals AI)61.8%88.9%GPT-6.1 Sol
Code migration (Vals AI)Not measured65.1%Only GPT-6.1 Sol measured
ProgramBench (Vals AI)Not measured3.0%Only GPT-6.1 Sol measured
IOI (Vals AI)53.8%96.9%GPT-6.1 Sol
SWE-bench Multimodal (Vals AI)Not measured43.5%Only GPT-6.1 Sol measured
CyberBench (Vals AI)Not measured39.3%Only GPT-6.1 Sol measured
SciCodeNot measured55.8%Only GPT-6.1 Sol measured
Terminal-Bench Hard (Artificial Analysis run)53.0%Not measuredOnly GPT-5.3-Codex measured
Terminal-Bench78.4%Not measuredOnly GPT-5.3-Codex measured
FrontierCodeNot measured50.2%Only GPT-6.1 Sol measured
WeirdML79.3%Not measuredOnly GPT-5.3-Codex measured
ALE-Bench1655.22743.8GPT-6.1 Sol
LMArena Text: codingNot measured1478Only GPT-6.1 Sol measured
LMArena Text: software and ITNot measured1476Only GPT-6.1 Sol measured
LMArena WebDev: React13951754GPT-6.1 Sol
LMArena WebDev: HTML14221800GPT-6.1 Sol
LMArena WebDev: from an image14431702GPT-6.1 Sol
Neither model has a result on the other 16 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index02
Intelligence benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
AA Intelligence Index32.551.8GPT-6.1 Sol
Epoch Capabilities Index157.1168.4GPT-6.1 Sol
Agentic workLike-for-likePublic boards, shown as published, kept out of the index01
Agentic work benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
Design Arena: agents building web apps1033Not measuredOnly GPT-5.3-Codex measured
Design Arena: agents building full-stack apps983Not measuredOnly GPT-5.3-Codex measured
Design Arena: agents building mobile apps10541190GPT-6.1 Sol
Design Arena: agents building Android apps1084Not measuredOnly GPT-5.3-Codex measured
Design Arena: agents building Godot games1124Not measuredOnly GPT-5.3-Codex measured
Design Arena: spreadsheetsNot measured1250Only GPT-6.1 Sol measured
LiveBench researchNot measured83.5%Only GPT-6.1 Sol measured
LiveBench browserNot measured88.0%Only GPT-6.1 Sol measured
LiveBench long agenticNot measured73.0%Only GPT-6.1 Sol measured
SREBench (Vals AI)Not measured50.8%Only GPT-6.1 Sol measured
Finance Agent (Vals AI)Not measured52.0%Only GPT-6.1 Sol measured
Tax Agent Bench (Vals AI)Not measured21.8%Only GPT-6.1 Sol measured
Legal Research Bench (Vals AI)Not measured38.5%Only GPT-6.1 Sol measured
Harvey's Legal Agent Benchmark (Vals AI)Not measured6.3%Only GPT-6.1 Sol measured
Excel Modeling Benchmark (Vals AI)Not measured70.8%Only GPT-6.1 Sol measured
BioMysteryBench (Vals AI)Not measured79.6%Only GPT-6.1 Sol measured
Terminal-Bench-Science (Vals AI)Not measured52.9%Only GPT-6.1 Sol measured
Vals Science IndexNot measured59.6%Only GPT-6.1 Sol measured
Robo-bench (Vals AI)Not measured28.3%Only GPT-6.1 Sol measured
τ²-Bench Telecom86.0%Not measuredOnly GPT-5.3-Codex measured
APEX-AgentsNot measured60.0%Only GPT-6.1 Sol measured
METR time horizons74.5%Not measuredOnly GPT-5.3-Codex measured
SpireClimbNot measured24.7%Only GPT-6.1 Sol measured
Vending-Bench 2$5,940Not measuredOnly GPT-5.3-Codex measured
Neither model has a result on the other 15 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index01
Reasoning benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
LiveBench reasoningNot measured92.6%Only GPT-6.1 Sol measured
MysteryMechanism (Vals AI)Not measured46.4%Only GPT-6.1 Sol measured
GPQA Diamond (Artificial Analysis run)91.5%Not measuredOnly GPT-5.3-Codex measured
Humanity's Last Exam (Artificial Analysis run)42.5%52.9%GPT-6.1 Sol
GPQA Diamond (Epoch AI run)Not measured95.4%Only GPT-6.1 Sol measured
ARC-AGINot measured98.5%Only GPT-6.1 Sol measured
ARC-AGI-2Not measured94.2%Only GPT-6.1 Sol measured
Chess puzzlesNot measured68.0%Only GPT-6.1 Sol measured
Mystery game puzzlesNot measured80.0%Only GPT-6.1 Sol measured
EBR-benchNot measured54.3%Only GPT-6.1 Sol measured
LMArena Text: hard promptsNot measured1463Only GPT-6.1 Sol measured
LMArena Text: expertNot measured1489Only GPT-6.1 Sol measured
LMArena Text: hard prompts in EnglishNot measured1465Only GPT-6.1 Sol measured
LMArena Vision: diagramsNot measured1306Only GPT-6.1 Sol measured
LMArena Vision: homeworkNot measured1356Only GPT-6.1 Sol measured
Neither model has a result on the other 6 boards here
MathDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
Math benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
OTIS Mock AIMENot measured100.0%Only GPT-6.1 Sol measured
FrontierMath, tiers 1 to 3Not measured93.7%Only GPT-6.1 Sol measured
FrontierMath, tier 4Not measured100.0%Only GPT-6.1 Sol measured
ProofBenchNot measured99.0%Only GPT-6.1 Sol measured
LMArena Text: mathNot measured1489Only GPT-6.1 Sol measured
LMArena Text: mathematical workNot measured1513Only GPT-6.1 Sol measured
Neither model has a result on the other 7 boards here
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index6 boards, none shared
Knowledge benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
MedCode (Vals AI)Not measured48.8%Only GPT-6.1 Sol measured
SimpleQA VerifiedNot measured73.9%Only GPT-6.1 Sol measured
LMArena Text: scienceNot measured1444Only GPT-6.1 Sol measured
LMArena Text: medicine and healthcareNot measured1433Only GPT-6.1 Sol measured
LMArena Text: legal and governmentNot measured1471Only GPT-6.1 Sol measured
LMArena Text: business and financeNot measured1445Only GPT-6.1 Sol measured
Neither model has a result on the other 11 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index06
Web design benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
Design Arena: websites11631321GPT-6.1 Sol
Design Arena: UI components11371321GPT-6.1 Sol
Design Arena: game dev11621389GPT-6.1 Sol
Design Arena: data viz11641278GPT-6.1 Sol
Design Arena: 3D10081461GPT-6.1 Sol
Design Arena: all code categories11451345GPT-6.1 Sol
Design Arena: SVG1129Not measuredOnly GPT-5.3-Codex measured
Design Arena: ASCII art1151Not measuredOnly GPT-5.3-Codex measured
LiveBench designNot measured82.1%Only GPT-6.1 Sol measured
GeneralLike-for-likePublic boards, shown as published, kept out of the index01
General benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
Vals IndexNot measured63.9%Only GPT-6.1 Sol measured
LiveBench data analysisNot measured82.7%Only GPT-6.1 Sol measured
Public Benefits Bench (Vals AI)Not measured59.3%Only GPT-6.1 Sol measured
SAGE (Vals AI)Not measured46.5%Only GPT-6.1 Sol measured
MedScribe (Vals AI)Not measured86.5%Only GPT-6.1 Sol measured
IFBench75.4%Not measuredOnly GPT-5.3-Codex measured
Long context reasoning (AA-LCR)83.3%84.0%GPT-6.1 Sol
DTBenchNot measured96.5%Only GPT-6.1 Sol measured
LMCANot measured62.8%Only GPT-6.1 Sol measured
Furniture assemblyNot measured80.0%Only GPT-6.1 Sol measured
LMArena TextNot measured1443Only GPT-6.1 Sol measured
LMArena Text: instruction followingNot measured1466Only GPT-6.1 Sol measured
LMArena Text: creative writingNot measured1425Only GPT-6.1 Sol measured
LMArena VisionNot measured1288Only GPT-6.1 Sol measured
LMArena Text: EnglishNot measured1450Only GPT-6.1 Sol measured
LMArena Text: non-EnglishNot measured1433Only GPT-6.1 Sol measured
LMArena Text: ChineseNot measured1487Only GPT-6.1 Sol measured
LMArena Text: FrenchNot measured1460Only GPT-6.1 Sol measured
LMArena Text: SpanishNot measured1439Only GPT-6.1 Sol measured
LMArena Text: RussianNot measured1457Only GPT-6.1 Sol measured
LMArena Text: multi-turnNot measured1442Only GPT-6.1 Sol measured
LMArena Text: longer queriesNot measured1458Only GPT-6.1 Sol measured
LMArena Text: writing and languageNot measured1444Only GPT-6.1 Sol measured
LMArena Text: entertainment and mediaNot measured1426Only GPT-6.1 Sol measured
LMArena Vision: EnglishNot measured1274Only GPT-6.1 Sol measured
LMArena Vision: reading textNot measured1289Only GPT-6.1 Sol measured
LMArena Vision: creative writingNot measured1301Only GPT-6.1 Sol measured
Neither model has a result on the other 19 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for GPT-5.3-Codex and GPT-6.1 Sol
BenchmarkGPT-5.3-CodexGPT-6.1 SolLeader
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-5.3-Codex$0.0088Fits in one request
GPT-6.1 Sol$0.0070Fits in one request

GPT-6.1 Sol costs less

Repository review

50K input + 3K output tokens

GPT-5.3-Codex$0.130Fits in one request
GPT-6.1 Sol$0.130Fits in one request

GPT-5.3-Codex costs less

Agent loop

200K input + 10K output tokens

GPT-5.3-Codex$0.490Fits in one request
GPT-6.1 Sol$0.500Fits in one request

GPT-5.3-Codex 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-5.3-Codex and GPT-6.1 Sol
SpecificationOpenAI GPT-5.3-CodexOpenAI GPT-6.1 Sol
MakerOpenAIOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedFebruary 24, 2026September 29, 2026
Context window400K1.05M
Input $/Mtok$1.75$2.00
Output $/Mtok$14.00$10.00
Coding index29.588.7
Independent measurements behind it12
Cost per solved task$0.59Not computable
SourceOpenRouter listingOpenRouter listing

Questions

Is GPT-5.3-Codex better than GPT-6.1 Sol for coding?

Pick GPT-6.1 Sol for coding: it scores 88.7 on the Vibe Coding Index against 29.5 for GPT-5.3-Codex. GPT-5.3-Codex is neither cheaper nor larger in context, and leads no benchmark both models were measured on.

Which is cheaper, GPT-5.3-Codex or GPT-6.1 Sol?

GPT-5.3-Codex costs $1.75 per million input tokens and $14.00 per million output tokens; GPT-6.1 Sol costs $2.00 and $10.00. Cost per solved task is known for GPT-5.3-Codex only.

Which has the bigger context window, GPT-5.3-Codex or GPT-6.1 Sol?

GPT-6.1 Sol, with 1.05M tokens against 400K.

How many benchmarks is the GPT-5.3-Codex vs GPT-6.1 Sol comparison based on?

18 benchmarks have a result for both models as of October 21, 2026. GPT-5.3-Codex's coding index rests on 1 independent benchmark and GPT-6.1 Sol's on 2. Where only one model has a result, the page says so instead of naming a winner.

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