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Model comparison

Claude Haiku 4.5 vs GPT-5.5

Data verified

Head-to-head evidence from 4 shared benchmark results across 3 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

56.58/100
Margin
16.9pts
winning →
OpenAI
73.51/100
1 category wins1 category wins

Public leaderboard positions: Claude Haiku 4.5 #77 (Estimated); GPT-5.5 #9 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Claude Haiku 4.5 and GPT-5.5 share 4 comparable benchmark results. 2 of 8 categories are comparable. 1 result is unique to Claude Haiku 4.5; 53 to GPT-5.5.

Updated July 22, 2026
Shared results
4
Claude Haiku 4.5 only
1
GPT-5.5 only
53
Comparable categories
2 / 8

Pick GPT-5.5 if you want the stronger benchmark profile. Claude Haiku 4.5 only becomes the better choice if coding is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 4 shared benchmark results across 3 evidence categories; 2 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

GPT-5.5 is clearly ahead on the BenchAlign aggregate, 73.51 to 56.58. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.5's sharpest advantage is in mathematics, where it averages 47.6 against 4.9. The single biggest benchmark swing on the page is FrontierMath v2 (Tiers 1-3), 5.903% to 51.700%. Claude Haiku 4.5 does hit back in coding, so the answer changes if that is the part of the workload you care about most.

GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $1.00 input / $5.00 output per 1M tokens for Claude Haiku 4.5. That is roughly 6.0x on output cost alone. GPT-5.5 is the reasoning model in the pair, while Claude Haiku 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.5 gives you the larger context window at 1M, compared with 200K for Claude Haiku 4.5.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Claude Haiku 4.5 and GPT-5.5
CategoryClaude Haiku 4.5ΔGPT-5.5
MathClaude Haiku 4.54.9Margin 42.7GPT-5.547.6
CodingClaude Haiku 4.573.3Margin 14.7GPT-5.558.6
AgenticClaude Haiku 4.5Not measuredMarginNo overlapGPT-5.581.6
ReasoningClaude Haiku 4.5Not measuredMarginNo overlapGPT-5.585.0
KnowledgeClaude Haiku 4.5Not measuredMarginNo overlapGPT-5.557.8
MultimodalClaude Haiku 4.5Not measuredMarginNo overlapGPT-5.570.4

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Claude Haiku 4.5B · GPT-5.5
  1. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 5.903%B 51.700%
    Winner: GPT-5.5Δ 45.8
    FrontierMath v2 (Tiers 1-3): Claude Haiku 4.5 scored 5.903%; GPT-5.5 scored 51.700%. GPT-5.5 wins this benchmark.
  2. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 2.083%B 35.400%
    Winner: GPT-5.5Δ 33.3
    FrontierMath v2 (Tier 4): Claude Haiku 4.5 scored 2.083%; GPT-5.5 scored 35.400%. GPT-5.5 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricClaude Haiku 4.5GPT-5.5Comparison
Input / output priceUSD per 1M tokensClaude Haiku 4.5$1 input / $5 outputGPT-5.5$5 input / $30 outputClaude Haiku 4.5 has the lower combined listed price.
Generation speedtokens per secondClaude Haiku 4.5Not availableGPT-5.5Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenClaude Haiku 4.5Not availableGPT-5.5Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensClaude Haiku 4.5200KGPT-5.51MGPT-5.5 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkClaude Haiku 4.5GPT-5.5Result
JobBenchSource 16.0%42.7%GPT-5.5 leads
Terminal-Bench 2.0Source 82%Not comparable
CyberGymSource 81.8%Not comparable
BrowseCompSource 84.4%Not comparable
OSWorld-VerifiedSource 78.7%Not comparable
MCP AtlasSource 75.3%Not comparable
ToolathlonSource 55.6%Not comparable
τ²-bench resultsSource 93.9%Not comparable
AA Agentic IndexSource 44.9%Not comparable
APEX-Agents-AASource 37.7%Not comparable
GDPval-AASource 49.5%Not comparable
GDPval-AASource 1490Not comparable
Gert LabsSource 72.93%Not comparable
ResearchClawBenchSource 17.0%Not comparable
OSWorld 2.0Source 13.0%Not comparable
ExploitGymSource 13.4%Not comparable
AA BriefcaseSource 1154Not comparable
AA AutomationBenchSource 42.1%Not comparable
AA EnterpriseOps-GymSource 46.6%Not comparable
AA Harvey LABSource 86.3%Not comparable
AA ITBenchSource 45.8%Not comparable
AA Tau3 BankingSource 31.3%Not comparable
terminalBenchHardSource 60.6%Not comparable
aaTerminalBench21Source 84.3%Not comparable
CodingClaude Haiku 4.5 wins
BenchmarkClaude Haiku 4.5GPT-5.5Result
SWE-bench VerifiedSource 73.3%Not comparable
SWE-bench ProSource 58.6%Not comparable
Terminal-Bench 2.0Source 82.0%Not comparable
Vibe Code BenchSource 69.85%Not comparable
React Native EvalsSource 84.7%Not comparable
cursorBench31Source 59.2%Not comparable
cursorBench32Source 58.4%Not comparable
AA Coding IndexSource 74.9%Not comparable
AA-SciCodeSource 56.1%Not comparable
FrontierCode 1.1 MainSource 43.0%Not comparable
Reasoning
BenchmarkClaude Haiku 4.5GPT-5.5Result
MRCR v2 64K-128KSource 83.1%Not comparable
MRCR v2 128K-256KSource 87.5%Not comparable
ARC-AGI-2Source 85%Not comparable
AA-LCRSource 74.3%Not comparable
CritPtSource 27.1%Not comparable
Knowledge
BenchmarkClaude Haiku 4.5GPT-5.5Result
GPQASource 93.6%Not comparable
GPQA-DSource 93.6%Not comparable
HLESource 52.2%Not comparable
HLE w/o toolsSource 41.4%Not comparable
Artificial Analysis Intelligence IndexSource 54.8%Not comparable
AA-GPQA DiamondSource 93.5%Not comparable
AA-HLESource 44.3%Not comparable
AA-Omniscience IndexSource 20.1%Not comparable
AA-Omniscience AccuracySource 56.9%Not comparable
AA-Omniscience Hallucination RateSource 85.5%Not comparable
MathGPT-5.5 wins
BenchmarkClaude Haiku 4.5GPT-5.5Result
FrontierMath v2 (Tiers 1-3)Source 5.903%51.700%GPT-5.5 leads
FrontierMath v2 (Tier 4)Source 2.083%35.400%GPT-5.5 leads
FrontierMath (legacy)Source 51.7%Not comparable
Multimodal
BenchmarkClaude Haiku 4.5GPT-5.5Result
Design Arena WebsiteSource 11521282GPT-5.5 leads
MMMU-ProSource 81.2%Not comparable
MMMU-Pro w/ PythonSource 83.2%Not comparable
OfficeQA ProSource 54.1%Not comparable
AA-MMMU-ProSource 79.9%Not comparable
Inst. Following
BenchmarkClaude Haiku 4.5GPT-5.5Result
AA-IFBenchSource 75.9%Not comparable
Frequently Asked Questions (3)

Which is better, Claude Haiku 4.5 or GPT-5.5?

GPT-5.5 is ahead on BenchLM's BenchAlign leaderboard, 73.51 to 56.58. The biggest single separator in this matchup is FrontierMath v2 (Tiers 1-3), where the scores are 5.903% and 51.700%.

Which is better for coding, Claude Haiku 4.5 or GPT-5.5?

Claude Haiku 4.5 has the edge for coding in this comparison, averaging 73.3 versus 58.6. GPT-5.5 stays close enough that the answer can still flip depending on your workload.

Which is better for math, Claude Haiku 4.5 or GPT-5.5?

GPT-5.5 has the edge for math in this comparison, averaging 47.6 versus 4.9. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.

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Last updated: July 22, 2026

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