Model comparison

Claude 3 Haiku vs GPT-5.3 Codex

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 25.9 on the Noometry Index.

Last verified . 2 shared benchmarks.

Claude 3 Haiku Anthropic

25.9

Rank #340 Confirmed

GPT-5.3 Codex OpenAI

45.8

Rank #69 Reported

Summary

  • They share 2 benchmarks with published results for both. Claude 3 Haiku scores higher in 0 categories and GPT-5.3 Codex in 1 category; one gap is clear of the uncertainty.
  • The widest gap is in coding, where GPT-5.3 Codex leads 48.6 to 26.4.
  • The biggest single-benchmark swing is WeirdML: 9.8% for Claude 3 Haiku and 79.3% for GPT-5.3 Codex.

Side by side

Claude 3 Haiku and GPT-5.3 Codex specifications
Claude 3 HaikuGPT-5.3 Codex
ProviderAnthropicOpenAI
Noometry Index25.945.8
Released2024-03-072026-02-05
WeightsProprietaryProprietary
Context window—400K
Max output—128K
Input $ / M tokens—$1.75
Output $ / M tokens—$14
Results tracked378

Sponsored placements are available on pages like this one. Advertise on Noometry

Category by category

Coding GPT-5.3 Codex leads

Claude 3 Haiku: 26.4 (#325), GPT-5.3 Codex: 48.6 (#56)

Coding benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
WeirdML9.8%79.3%
SWE-bench Verified—74.8%
LMArena WebDev—1409
BigCodeBench Instruct39.4%—
LMArena Coding1199—
BigCodeBench Complete50.1%—
CadEval12%—
ALE-Bench—1,655
HumanEval+68.9%—
MBPP+68.8%—

Agentic & Tool Use Not comparable

Claude 3 Haiku: —, GPT-5.3 Codex: 48.0 (#9)

Agentic & Tool Use benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
Terminal-Bench—78.4%
METR Time Horizons—74.5%
Vending-Bench 2—5,940

Reasoning Not comparable

Claude 3 Haiku: 16.3 (#307), GPT-5.3 Codex: —

Reasoning benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
Epoch Capabilities Index118.35156.77
Kagi LLM Benchmark34.2%—
LMArena Hard Prompts1174—
DTBench50.1%—
LMCA8.8%—
ForecastBench53.2—
WinoGrande74.2%—

Math Not comparable

Claude 3 Haiku: 9.8 (#319), GPT-5.3 Codex: —

Math benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
OTIS Mock AIME 2024-20251.8%—
LMArena Math1188—
MATH Level 514.9%—

Knowledge Not comparable

Claude 3 Haiku: 17.3 (#285), GPT-5.3 Codex: —

Knowledge benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
GPQA Diamond36.3%—
Confabulations34.2%—
LMArena Expert1148—
MMLU73.8%—

Multimodal Not comparable

Claude 3 Haiku: 23.6 (#128), GPT-5.3 Codex: —

Multimodal benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
LMArena Vision950—
ScienceQA72%—

Multilingual Not comparable

Claude 3 Haiku: 36.0 (#243), GPT-5.3 Codex: —

Multilingual benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
LMArena Non-English1178—
LMArena Chinese1155—
LMArena French1195—
LMArena German1174—
LMArena Japanese1102—
LMArena Korean1109—
LMArena Russian1204—
LMArena Spanish1166—

Instruction Following Not comparable

Claude 3 Haiku: 61.3 (#247), GPT-5.3 Codex: —

Instruction Following benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
LMArena Instruction Following1173—

Long Context Not comparable

Claude 3 Haiku: 36.1 (#237), GPT-5.3 Codex: —

Long Context benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
LMArena Longer Query1190—

Writing & Preference Not comparable

Claude 3 Haiku: 29.7 (#291), GPT-5.3 Codex: —

Writing & Preference benchmarks
BenchmarkClaude 3 HaikuGPT-5.3 Codex
LMArena Text1195—
LMArena Creative Writing1157—
EQ-Bench Creative Writing717—
LMArena Multi-Turn1190—

Frequently asked questions

Is Claude 3 Haiku better than GPT-5.3 Codex?

GPT-5.3 Codex is the stronger model overall, scoring 45.8 to 25.9 on the Noometry Index.

Is Claude 3 Haiku or GPT-5.3 Codex better for coding?

GPT-5.3 Codex scores higher on coding benchmarks: 48.6 versus 26.4 in the Noometry coding category.

How many benchmarks do Claude 3 Haiku and GPT-5.3 Codex share?

2 benchmarks have published results for both models. Claude 3 Haiku has 37 scored results on Noometry and GPT-5.3 Codex has 8.

Related comparisons

Go deeper