Model comparison

Claude Instant vs GPT-5.5 Pro

GPT-5.5 Pro has enough public results to be ranked (#8); Claude Instant does not yet, so treat this comparison as directional.

Last verified . 2 shared benchmarks.

Claude Instant Anthropic

29.5

Unranked Sparse

GPT-5.5 Pro OpenAI

64.3

Rank #8 Confirmed

Summary

  • They share 2 benchmarks with published results for both. Claude Instant scores higher in 0 categories and GPT-5.5 Pro in 1 category; one gap is clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 19.6.
  • The biggest single-benchmark swing is DTBench: 45.8% for Claude Instant and 96% for GPT-5.5 Pro.

Side by side

Claude Instant and GPT-5.5 Pro specifications
Claude InstantGPT-5.5 Pro
ProviderAnthropicOpenAI
Noometry Index29.564.3
Released2023-08-092026-04-23
WeightsProprietaryProprietary
Context window—1.05M
Max output—128K
Input $ / M tokens—$30
Output $ / M tokens—$180
Results tracked714

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Category by category

Coding Not comparable

Claude Instant: —, GPT-5.5 Pro: —

Coding benchmarks
BenchmarkClaude InstantGPT-5.5 Pro
HumanEval+50.6%—

Reasoning GPT-5.5 Pro leads

Claude Instant: 19.6, GPT-5.5 Pro: 73.3 (#10)

Reasoning benchmarks
BenchmarkClaude InstantGPT-5.5 Pro
DTBench45.8%96%
Epoch Capabilities Index120.28162.07
ARC-AGI-2—84.6%
SimpleBench—76.9%
ARC-AGI-1—96.5%
CritPt—30.6%
Chess Puzzles—64%
LMCA—53.9%

Math Not comparable

Claude Instant: —, GPT-5.5 Pro: 84.0 (#10)

Math benchmarks
BenchmarkClaude InstantGPT-5.5 Pro
FrontierMath (Tiers 1-3)—87.7%
FrontierMath Tier 4—78%
OTIS Mock AIME 2024-2025—100%
FrontierMath (Feb 2025 set)—52.4%
FrontierMath Tier 4 (v1)—39.6%
GSM8K86.7%—

Knowledge Not comparable

Claude Instant: —, GPT-5.5 Pro: 64.1 (#19)

Knowledge benchmarks
BenchmarkClaude InstantGPT-5.5 Pro
GPQA Diamond—93.9%
ARC (AI2) Challenge86.3%—
MMLU73.4%—
TriviaQA78.9%—

Frequently asked questions

Is Claude Instant better than GPT-5.5 Pro?

GPT-5.5 Pro has enough public results to be ranked (#8); Claude Instant does not yet, so treat this comparison as directional.

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

2 benchmarks have published results for both models. Claude Instant has 7 scored results on Noometry and GPT-5.5 Pro has 14.

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