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GPT-5.1-Codex vs GPT-5.2

Updated October 21, 2026. 26 benchmarks have a result for both. Coding is ranked on the Vibe Coding Index; every other board is shown as published.

Replace GPT-5.1-Codex Replace GPT-5.2
GPT-5.1-CodexOpenAI
Coding
50.5
Overall
23.7
Output $/M
$10.00
5
GPT-5.2OpenAI
Coding
58.9
Overall
30.4
Output $/M
$14.00
21
vs boards won of 26 shared

Decision reading

Pick GPT-5.2 for coding: it scores 58.9 on the Vibe Coding Index against 50.5 for GPT-5.1-Codex.

Pick GPT-5.1-Codex when output tokens cost 1.4x less, or when a solved task costs $0.892 against $1.91.

Model AGPT-5.1-CodexOpenAI50.5/1002 independent benchmarks$0.892 per solved taskModel BGPT-5.2OpenAI58.9/1002 independent benchmarks$1.91 per solved task
Shared results
26
GPT-5.1-Codex only
0
GPT-5.2 only
85
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-5.1-Codex 50.5 from 2 benchmarks, GPT-5.2 58.9 from 2 benchmarks.
Widest category
Coding, 10.8 points apart on average over 9 shared benchmarks.
Widest single gap
Vibe Code Bench (Vals AI): GPT-5.1-Codex 13.1% against GPT-5.2 53.5%, 40.4 points apart on a 0 to 100 scale.
Output price
GPT-5.1-Codex $10.00 against GPT-5.2 $14.00 per million output tokens, 1.4x apart.
Context window
Both take 400K tokens.

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-5.1-CodexBarsGPT-5.2Ties
Coding18
Intelligence01
Agentic work22
Reasoning02
Math02
Knowledge01
Web design23
General02
All shared boards521
CodingLike-for-likeFour of these boards feed the Vibe Coding Index18
Coding benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
SWE-bench Verified66.0%72.8%GPT-5.2
SWE-bench MultilingualNot measured66.7%Only GPT-5.2 measured
LMArena WebDev13371417GPT-5.2
LiveCodeBench (Vals AI)85.5%85.4%GPT-5.1-Codex
SWE-bench Verified (Vals AI)Not measured75.8%Only GPT-5.2 measured
Vibe Code Bench (Vals AI)13.1%53.5%GPT-5.2
LiveCodeBench (Artificial Analysis run)84.9%89.4%GPT-5.2
Terminal-Bench Hard (Artificial Analysis run)34.8%47.0%GPT-5.2
Terminal-Bench57.8%64.9%GPT-5.2
GSO-BenchNot measured27.5%Only GPT-5.2 measured
WeirdMLNot measured72.2%Only GPT-5.2 measured
ALE-Bench1244.91293.5GPT-5.2
LMArena Text: codingNot measured1442Only GPT-5.2 measured
LMArena Text: software and ITNot measured1434Only GPT-5.2 measured
LMArena WebDev: HTML13461427GPT-5.2
Neither model has a result on the other 23 boards here
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index01
Intelligence benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
AA Intelligence Index23.730.4GPT-5.2
Epoch Capabilities IndexNot measured153.7Only GPT-5.2 measured
Agentic workLike-for-likePublic boards, shown as published, kept out of the index22
Agentic work benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
Design Arena: agents building web apps10181086GPT-5.2
Design Arena: agents building full-stack apps10861043GPT-5.1-Codex
Design Arena: agents building mobile apps11911094GPT-5.1-Codex
Design Arena: agents building Android appsNot measured1064Only GPT-5.2 measured
Design Arena: agents building Godot gamesNot measured1142Only GPT-5.2 measured
τ²-Bench Telecom83.0%84.8%GPT-5.2
METR time horizonsNot measured75.3%Only GPT-5.2 measured
Remote Labor IndexNot measured2.5%Only GPT-5.2 measured
GDPvalNot measured49.7%Only GPT-5.2 measured
DeepResearch BenchNot measured41.1%Only GPT-5.2 measured
Vending-Bench 2Not measured$3,591Only GPT-5.2 measured
Neither model has a result on the other 28 boards here
ReasoningLike-for-likePublic boards, shown as published, kept out of the index02
Reasoning benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
GPQA DiamondNot measured91.7%Only GPT-5.2 measured
MMMU Pro (Vals AI)Not measured86.7%Only GPT-5.2 measured
GPQA Diamond (Artificial Analysis run)86.0%90.3%GPT-5.2
Humanity's Last Exam (Artificial Analysis run)25.7%37.7%GPT-5.2
GPQA Diamond (Epoch AI run)Not measured91.4%Only GPT-5.2 measured
ARC-AGINot measured86.2%Only GPT-5.2 measured
ARC-AGI-2Not measured52.9%Only GPT-5.2 measured
SimpleBenchNot measured45.8%Only GPT-5.2 measured
Chess puzzlesNot measured48.0%Only GPT-5.2 measured
Mystery game puzzlesNot measured23.0%Only GPT-5.2 measured
EBR-benchNot measured23.0%Only GPT-5.2 measured
VPCTNot measured84.0%Only GPT-5.2 measured
LMArena Text: hard promptsNot measured1428Only GPT-5.2 measured
LMArena Text: expertNot measured1445Only GPT-5.2 measured
LMArena Text: hard prompts in EnglishNot measured1431Only GPT-5.2 measured
LMArena Vision: diagramsNot measured1265Only GPT-5.2 measured
LMArena Vision: homeworkNot measured1276Only GPT-5.2 measured
Neither model has a result on the other 4 boards here
MathLike-for-likePublic boards, shown as published, kept out of the index02
Math benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
AIMENot measured96.9%Only GPT-5.2 measured
MGSM (Vals AI)Not measured94.0%Only GPT-5.2 measured
AA Math Index95.799.0GPT-5.2
AIME 2025 (Artificial Analysis run)95.7%99.0%GPT-5.2
OTIS Mock AIMENot measured96.1%Only GPT-5.2 measured
FrontierMath, tiers 1 to 3Not measured67.4%Only GPT-5.2 measured
FrontierMath, tier 4Not measured31.7%Only GPT-5.2 measured
ProofBenchNot measured15.0%Only GPT-5.2 measured
LMArena Text: mathNot measured1440Only GPT-5.2 measured
LMArena Text: mathematical workNot measured1442Only GPT-5.2 measured
Neither model has a result on the other 3 boards here
KnowledgeLike-for-likePublic boards, shown as published, kept out of the index01
Knowledge benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
MMLU ProNot measured86.2%Only GPT-5.2 measured
LegalBench (Vals AI)Not measured82.8%Only GPT-5.2 measured
CaseLaw (Vals AI)Not measured66.0%Only GPT-5.2 measured
CorpFin (Vals AI)Not measured65.9%Only GPT-5.2 measured
TaxEval (Vals AI)Not measured75.8%Only GPT-5.2 measured
MortgageTax (Vals AI)Not measured67.1%Only GPT-5.2 measured
MedQA (Vals AI)Not measured94.1%Only GPT-5.2 measured
MedCode (Vals AI)Not measured49.8%Only GPT-5.2 measured
MMLU Pro (Artificial Analysis run)86.0%87.4%GPT-5.2
SimpleQA VerifiedNot measured37.1%Only GPT-5.2 measured
LMArena Text: scienceNot measured1425Only GPT-5.2 measured
LMArena Text: medicine and healthcareNot measured1425Only GPT-5.2 measured
LMArena Text: legal and governmentNot measured1427Only GPT-5.2 measured
LMArena Text: business and financeNot measured1414Only GPT-5.2 measured
Neither model has a result on the other 3 boards here
Web designLike-for-likePublic boards, shown as published, kept out of the index23
Web design benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
Design Arena: websites11621196GPT-5.2
Design Arena: UI components12371190GPT-5.1-Codex
Design Arena: game dev11381196GPT-5.2
Design Arena: data viz12131202GPT-5.1-Codex
Design Arena: 3DNot measured1079Only GPT-5.2 measured
Design Arena: all code categories11531171GPT-5.2
Design Arena: SVGNot measured1137Only GPT-5.2 measured
Design Arena: ASCII artNot measured1153Only GPT-5.2 measured
Neither model has a result on the other 1 board here
GeneralLike-for-likePublic boards, shown as published, kept out of the index02
General benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
SAGE (Vals AI)Not measured49.3%Only GPT-5.2 measured
MedScribe (Vals AI)Not measured84.4%Only GPT-5.2 measured
IFBench70.0%75.4%GPT-5.2
Long context reasoning (AA-LCR)69.3%82.7%GPT-5.2
DTBenchNot measured90.9%Only GPT-5.2 measured
LMCANot measured43.9%Only GPT-5.2 measured
CL-benchNot measured18.2%Only GPT-5.2 measured
Furniture assemblyNot measured38.3%Only GPT-5.2 measured
LMArena TextNot measured1416Only GPT-5.2 measured
LMArena Text: instruction followingNot measured1409Only GPT-5.2 measured
LMArena Text: creative writingNot measured1376Only GPT-5.2 measured
LMArena VisionNot measured1246Only GPT-5.2 measured
LMArena Text: EnglishNot measured1422Only GPT-5.2 measured
LMArena Text: non-EnglishNot measured1405Only GPT-5.2 measured
LMArena Text: ChineseNot measured1447Only GPT-5.2 measured
LMArena Text: GermanNot measured1444Only GPT-5.2 measured
LMArena Text: JapaneseNot measured1420Only GPT-5.2 measured
LMArena Text: KoreanNot measured1374Only GPT-5.2 measured
LMArena Text: FrenchNot measured1454Only GPT-5.2 measured
LMArena Text: SpanishNot measured1413Only GPT-5.2 measured
LMArena Text: RussianNot measured1415Only GPT-5.2 measured
LMArena Text: PolishNot measured1426Only GPT-5.2 measured
LMArena Text: multi-turnNot measured1419Only GPT-5.2 measured
LMArena Text: longer queriesNot measured1413Only GPT-5.2 measured
LMArena Text: writing and languageNot measured1392Only GPT-5.2 measured
LMArena Text: entertainment and mediaNot measured1378Only GPT-5.2 measured
LMArena Vision: EnglishNot measured1243Only GPT-5.2 measured
LMArena Vision: ChineseNot measured1305Only GPT-5.2 measured
LMArena Vision: reading textNot measured1257Only GPT-5.2 measured
LMArena Vision: humorNot measured1227Only GPT-5.2 measured
LMArena Vision: captioningNot measured1267Only GPT-5.2 measured
LMArena Vision: recognizing thingsNot measured1232Only GPT-5.2 measured
LMArena Vision: creative writingNot measured1225Only GPT-5.2 measured
LMArena DocumentNot measured1405Only GPT-5.2 measured
Neither model has a result on the other 12 boards here
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
Image generation benchmarks for GPT-5.1-Codex and GPT-5.2
BenchmarkGPT-5.1-CodexGPT-5.2Leader
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-Codex$0.0063Fits in one request
GPT-5.2$0.0088Fits in one request

GPT-5.1-Codex costs less

Repository review

50K input + 3K output tokens

GPT-5.1-Codex$0.092Fits in one request
GPT-5.2$0.130Fits in one request

GPT-5.1-Codex costs less

Agent loop

200K input + 10K output tokens

GPT-5.1-Codex$0.350Fits in one request
GPT-5.2$0.490Fits in one request

GPT-5.1-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-5.1-Codex and GPT-5.2
SpecificationOpenAI GPT-5.1-CodexOpenAI GPT-5.2
MakerOpenAIOpenAI
WeightsNo public weights listedNo public weights listed
ReleasedNovember 13, 2025December 10, 2025
Context window400K400K
Input $/Mtok$1.25$1.75
Output $/Mtok$10.00$14.00
Coding index50.558.9
Independent measurements behind it22
Cost per solved task$0.892$1.91
SourceOpenRouter listingOpenRouter listing

Questions

Is GPT-5.1-Codex better than GPT-5.2 for coding?

Pick GPT-5.2 for coding: it scores 58.9 on the Vibe Coding Index against 50.5 for GPT-5.1-Codex. Pick GPT-5.1-Codex when output tokens cost 1.4x less, or when a solved task costs $0.892 against $1.91.

Which is cheaper, GPT-5.1-Codex or GPT-5.2?

GPT-5.1-Codex costs $1.25 per million input tokens and $10.00 per million output tokens; GPT-5.2 costs $1.75 and $14.00. Per solved SWE-bench Verified task, GPT-5.1-Codex costs $0.892 and GPT-5.2 $1.91.

Which has the bigger context window, GPT-5.1-Codex or GPT-5.2?

Neither: both take 400K tokens.

How many benchmarks is the GPT-5.1-Codex vs GPT-5.2 comparison based on?

26 benchmarks have a result for both models as of October 21, 2026. GPT-5.1-Codex's coding index rests on 2 independent benchmarks and GPT-5.2's on 2. Where only one model has a result, the page says so instead of naming a winner.

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<p style="font:13px/1.4 sans-serif;margin:6px 0 0">Source: <a href="https://llmbenchmark.ai/compare/gpt-5-1-codex-vs-gpt-5-2">LLMBenchmark.ai, GPT-5.1-Codex vs GPT-5.2</a></p>