Model comparison

Claude Haiku 5.5 vs GPT-5-Codex

Claude Haiku 5.5 is the stronger model overall, scoring 49.5 to 37.9 on the Noometry Index.

Last verified . 0 shared benchmarks.

Claude Haiku 5.5 Anthropic

49.5

Rank #52 Confirmed

GPT-5-Codex OpenAI

37.9

Rank #192 Reported

Summary

  • The widest gap is in coding, where Claude Haiku 5.5 leads 49.2 to 42.4.
  • Claude Haiku 5.5 is cheaper at $0.10 / $0.50 per million input/output tokens, against $1.25 / $10 for GPT-5-Codex.
  • Claude Haiku 5.5 accepts more context: 1M tokens versus 400K.

Side by side

Claude Haiku 5.5 and GPT-5-Codex specifications
Claude Haiku 5.5GPT-5-Codex
ProviderAnthropicOpenAI
Noometry Index49.537.9
Released2026-10-072025-09-15
WeightsProprietaryProprietary
Context window1M400K
Max output128K128K
Input $ / M tokens$0.10$1.25
Output $ / M tokens$0.50$10
Results tracked93

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Category by category

Coding Claude Haiku 5.5 leads

Claude Haiku 5.5: 49.2 (#50), GPT-5-Codex: 42.4 (#103)

Coding benchmarks
BenchmarkClaude Haiku 5.5GPT-5-Codex
LMArena WebDev1587—
WeirdML—54.5%

Agentic & Tool Use Not comparable

Claude Haiku 5.5: —, GPT-5-Codex: 31.0 (#72)

Agentic & Tool Use benchmarks
BenchmarkClaude Haiku 5.5GPT-5-Codex
Terminal-Bench—44.3%

Reasoning Claude Haiku 5.5 leads

Claude Haiku 5.5: 35.2 (#69), GPT-5-Codex: 30.9 (#83)

Reasoning benchmarks
BenchmarkClaude Haiku 5.5GPT-5-Codex
Kagi LLM Benchmark—70.3%
NYT Connections (extended)65.7%—
Mystery Game Puzzles30%—

Math Not comparable

Claude Haiku 5.5: 73.6 (#18), GPT-5-Codex: —

Math benchmarks
BenchmarkClaude Haiku 5.5GPT-5-Codex
FrontierMath (Tiers 1-3)75.1%—
FrontierMath Tier 446.3%—
OTIS Mock AIME 2024-202598.9%—

Knowledge Not comparable

Claude Haiku 5.5: 50.8 (#70), GPT-5-Codex: —

Knowledge benchmarks
BenchmarkClaude Haiku 5.5GPT-5-Codex
GPQA Diamond89.6%—
SimpleQA Verified23.8%—

Multimodal Not comparable

Claude Haiku 5.5: 43.7 (#21), GPT-5-Codex: —

Multimodal benchmarks
BenchmarkClaude Haiku 5.5GPT-5-Codex
Furniture Assembly47.5%—

Frequently asked questions

Is Claude Haiku 5.5 better than GPT-5-Codex?

Claude Haiku 5.5 is the stronger model overall, scoring 49.5 to 37.9 on the Noometry Index.

Which is cheaper, Claude Haiku 5.5 or GPT-5-Codex?

Claude Haiku 5.5 is cheaper. It lists at $0.10 per million input tokens and $0.50 per million output tokens; GPT-5-Codex lists at $1.25 and $10.

Is Claude Haiku 5.5 or GPT-5-Codex better for coding?

Claude Haiku 5.5 scores higher on coding benchmarks: 49.2 versus 42.4 in the Noometry coding category.

Which has the bigger context window?

Claude Haiku 5.5 does, with 1M tokens against 400K.

How many benchmarks do Claude Haiku 5.5 and GPT-5-Codex share?

0 benchmarks have published results for both models. Claude Haiku 5.5 has 9 scored results on Noometry and GPT-5-Codex has 3.

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