Model comparison

Claude Haiku 4.5 vs GPT-5.5 Pro

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 39.5 on the Noometry Index. Claude Haiku 4.5 costs 34× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

Last verified . 11 shared benchmarks.

Claude Haiku 4.5 Anthropic

39.5

Rank #165 Confirmed

GPT-5.5 Pro OpenAI

64.3

Rank #8 Confirmed

Summary

  • They share 11 benchmarks with published results for both. Claude Haiku 4.5 scores higher in 0 categories and GPT-5.5 Pro in 3 categories; 3 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 15.1.
  • The biggest single-benchmark swing is ARC-AGI-2: 4% for Claude Haiku 4.5 and 84.6% for GPT-5.5 Pro.
  • Claude Haiku 4.5 is cheaper at $1 / $5 per million input/output tokens, against $30 / $180 for GPT-5.5 Pro.
  • GPT-5.5 Pro accepts more context: 1.05M tokens versus 200K.

Side by side

Claude Haiku 4.5 and GPT-5.5 Pro specifications
Claude Haiku 4.5GPT-5.5 Pro
ProviderAnthropicOpenAI
Noometry Index39.564.3
Released2025-10-152026-04-23
WeightsProprietaryProprietary
Context window200K1.05M
Max output64K128K
Input $ / M tokens$1$30
Output $ / M tokens$5$180
Results tracked5314

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Category by category

Coding Not comparable

Claude Haiku 4.5: 44.0 (#78), GPT-5.5 Pro: —

Coding benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
SWE-bench Verified (bash only)66.6%—
LMArena WebDev1330—
SWE-bench Multilingual64.7%—
SciCode43.3%—
WeirdML45.4%—
LMArena Coding1453—
ALE-Bench653.48—

Agentic & Tool Use Not comparable

Claude Haiku 4.5: 33.6 (#52), GPT-5.5 Pro: —

Agentic & Tool Use benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
Terminal-Bench35.5%—
Berkeley Function Calling Leaderboard68.7%—
DeepResearch Bench45.5%—
BALROG31.2%—
ExploitBench13.7%—
Vending-Bench 2458.89—

Reasoning GPT-5.5 Pro leads

Claude Haiku 4.5: 15.1 (#320), GPT-5.5 Pro: 73.3 (#10)

Reasoning benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
ARC-AGI-24%84.6%
ARC-AGI-147.7%96.5%
CritPt0%30.6%
Chess Puzzles8%64%
DTBench73.6%96%
LMCA30.9%53.9%
Epoch Capabilities Index142.41162.07
SimpleBench—76.9%
NYT Connections (extended)14.3%—
LMArena Hard Prompts1420—
ForecastBench61.4—

Math GPT-5.5 Pro leads

Claude Haiku 4.5: 44.9 (#78), GPT-5.5 Pro: 84.0 (#10)

Math benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
OTIS Mock AIME 2024-202566.7%100%
FrontierMath (Feb 2025 set)5.9%52.4%
FrontierMath Tier 4 (v1)2.1%39.6%
FrontierMath (Tiers 1-3)—87.7%
FrontierMath Tier 4—78%
Omni-MATH56.1%—
LMArena Math1396—
MATH Level 596.4%—

Knowledge GPT-5.5 Pro leads

Claude Haiku 4.5: 37.7 (#153), GPT-5.5 Pro: 64.1 (#19)

Knowledge benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
GPQA Diamond71.2%93.9%
SimpleQA Verified13.2%—
MMLU-Pro77.7%—
Vectara Hallucination Rate9.8%—
GPQA (HELM)60.5%—
LMArena Expert1442—

Multimodal Not comparable

Claude Haiku 4.5: 26.8 (#118), GPT-5.5 Pro: —

Multimodal benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
Blueprint-Bench 20%—
LMArena Document1420—

Multilingual Not comparable

Claude Haiku 4.5: 49.9 (#129), GPT-5.5 Pro: —

Multilingual benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
LMArena Non-English1377—
LMArena Chinese1417—
LMArena French1408—
LMArena German1375—
LMArena Japanese1339—
LMArena Korean1347—
LMArena Russian1381—
LMArena Spanish1420—

Instruction Following Not comparable

Claude Haiku 4.5: 71.4 (#149), GPT-5.5 Pro: —

Instruction Following benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
IFEval80.1%—
LMArena Instruction Following1414—

Long Context Not comparable

Claude Haiku 4.5: 43.6 (#92), GPT-5.5 Pro: —

Long Context benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
LMArena Longer Query1427—

Writing & Preference Not comparable

Claude Haiku 4.5: 57.9 (#123), GPT-5.5 Pro: —

Writing & Preference benchmarks
BenchmarkClaude Haiku 4.5GPT-5.5 Pro
LMArena Text1396—
LMArena Creative Writing1372—
WildBench83.9%—
EQ-Bench 41064—
LMArena Multi-Turn1409—

Frequently asked questions

Is Claude Haiku 4.5 better than GPT-5.5 Pro?

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 39.5 on the Noometry Index. Claude Haiku 4.5 costs 34× less per token, which makes it the better buy when GPT-5.5 Pro's lead doesn't matter for your workload.

Which is cheaper, Claude Haiku 4.5 or GPT-5.5 Pro?

Claude Haiku 4.5 is cheaper. It lists at $1 per million input tokens and $5 per million output tokens; GPT-5.5 Pro lists at $30 and $180.

Which has the bigger context window?

GPT-5.5 Pro does, with 1.05M tokens against 200K.

How many benchmarks do Claude Haiku 4.5 and GPT-5.5 Pro share?

11 benchmarks have published results for both models. Claude Haiku 4.5 has 53 scored results on Noometry and GPT-5.5 Pro has 14.

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