Model comparison

GPT-5.2 Codex vs GPT-5.5 Instant

GPT-5.2 Codex and GPT-5.5 Instant score almost the same on the Noometry Index (42.2 vs 42.5), so choose on price, context window or the category you care about most.

Last verified . 0 shared benchmarks.

GPT-5.2 Codex OpenAI

42.2

Rank #107 Reported

GPT-5.5 Instant OpenAI

42.5

Rank #99 Confirmed

Side by side

GPT-5.2 Codex and GPT-5.5 Instant specifications
GPT-5.2 CodexGPT-5.5 Instant
ProviderOpenAIOpenAI
Noometry Index42.242.5
Released2025-12-182026-05-05
WeightsProprietaryProprietary
Context window400K—
Max output128K—
Input $ / M tokens$1.75—
Output $ / M tokens$14—
Results tracked527

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Category by category

Coding GPT-5.2 Codex leads

GPT-5.2 Codex: 45.4 (#66), GPT-5.5 Instant: 43.7 (#73)

Coding benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
SWE-bench Verified (bash only)72.8%—
LMArena WebDev1339—
SWE-bench Multilingual66.3%—
SciCode—48.6%
LMArena Coding—1433
ALE-Bench1,300—

Agentic & Tool Use Not comparable

GPT-5.2 Codex: 40.7 (#20), GPT-5.5 Instant: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
Terminal-Bench66.5%—

Reasoning Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 24.2 (#149)

Reasoning benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
CritPt—0%
Chess Puzzles—12%
LMArena Hard Prompts—1426
Epoch Capabilities Index—142.48

Math Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 26.1 (#241)

Math benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
FrontierMath (Tiers 1-3)—26.3%
FrontierMath Tier 4—2.4%
OTIS Mock AIME 2024-2025—68.1%
LMArena Math—1420

Knowledge Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 48.9 (#68)

Knowledge benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
GPQA Diamond—82.5%
LMArena Expert—1409

Multimodal Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 39.3 (#48)

Multimodal benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
LMArena Vision—1250
LMArena Document—1403

Multilingual Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 53.0 (#76)

Multilingual benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
LMArena Non-English—1417
LMArena Chinese—1457
LMArena French—1428
LMArena German—1410
LMArena Japanese—1408
LMArena Korean—1393
LMArena Russian—1430
LMArena Spanish—1430

Instruction Following Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 74.4 (#94)

Instruction Following benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
LMArena Instruction Following—1407

Long Context Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 43.4 (#92)

Long Context benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
LMArena Longer Query—1422

Writing & Preference Not comparable

GPT-5.2 Codex: —, GPT-5.5 Instant: 62.0 (#81)

Writing & Preference benchmarks
BenchmarkGPT-5.2 CodexGPT-5.5 Instant
LMArena Text—1419
LMArena Creative Writing—1420
LMArena Multi-Turn—1434

Frequently asked questions

Is GPT-5.2 Codex better than GPT-5.5 Instant?

GPT-5.2 Codex and GPT-5.5 Instant score almost the same on the Noometry Index (42.2 vs 42.5), so choose on price, context window or the category you care about most.

Is GPT-5.2 Codex or GPT-5.5 Instant better for coding?

GPT-5.2 Codex scores higher on coding benchmarks: 45.4 versus 43.7 in the Noometry coding category.

How many benchmarks do GPT-5.2 Codex and GPT-5.5 Instant share?

0 benchmarks have published results for both models. GPT-5.2 Codex has 5 scored results on Noometry and GPT-5.5 Instant has 27.

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