Model comparison

Claude Opus 5.5 vs GPT-5.4 mini

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 44.8 on the Noometry Index. GPT-5.4 mini costs 4.7× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Last verified . 28 shared benchmarks.

Claude Opus 5.5 Anthropic

68.5

Rank #3 Confirmed

GPT-5.4 mini OpenAI

44.8

Rank #69 Confirmed

Summary

  • They share 28 benchmarks with published results for both. Claude Opus 5.5 scores higher in 10 categories and GPT-5.4 mini in 0 categories; 10 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where Claude Opus 5.5 leads 79.5 to 30.3.
  • The biggest single-benchmark swing is FrontierMath Tier 4: 95% for Claude Opus 5.5 and 9.8% for GPT-5.4 mini.
  • GPT-5.4 mini is cheaper at $0.75 / $4.50 per million input/output tokens, against $4 / $20 for Claude Opus 5.5.
  • Claude Opus 5.5 accepts more context: 1M tokens versus 400K.

Side by side

Claude Opus 5.5 and GPT-5.4 mini specifications
Claude Opus 5.5GPT-5.4 mini
ProviderAnthropicOpenAI
Noometry Index68.544.8
Released2026-09-222026-03-17
WeightsProprietaryProprietary
Context window1M400K
Max output128K128K
Input $ / M tokens$4$0.75
Output $ / M tokens$20$4.50
Results tracked3546

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Category by category

Coding Claude Opus 5.5 leads

Claude Opus 5.5: 71.4 (#1), GPT-5.4 mini: 45.0 (#67)

Coding benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
FrontierCode54.4%27%
LMArena WebDev18201397
SciCode66.9%49.9%
LMArena Coding15451438
CursorBench57.8%—
FrontierSWE62.3%—
WeirdML—60.3%
MirrorCode77.4%—
ALE-Bench—1,189

Agentic & Tool Use Claude Opus 5.5 leads

Claude Opus 5.5: 45.3 (#13), GPT-5.4 mini: 29.6 (#74)

Agentic & Tool Use benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
APEX-Agents73.5%—
DeepResearch Bench—36.3%
GDP.pdf30.6%—

Reasoning Claude Opus 5.5 leads

Claude Opus 5.5: 79.5 (#2), GPT-5.4 mini: 30.3 (#77)

Reasoning benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
ARC-AGI-292.5%18.9%
NYT Connections (extended)88.5%61.8%
ARC-AGI-197.5%63.7%
CritPt31.7%10%
LMArena Hard Prompts15451424
Mystery Game Puzzles71%11%
DTBench98.9%80%
LMCA68.2%40.8%
Kagi LLM Benchmark—37.9%
Chess Puzzles—24%
Thematic Generalization—61.7%
EBR-Bench71.4%—
Epoch Capabilities Index—148.83
ForecastBench—57

Math Claude Opus 5.5 leads

Claude Opus 5.5: 92.4 (#2), GPT-5.4 mini: 45.4 (#63)

Math benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
FrontierMath (Tiers 1-3)91.2%51.2%
FrontierMath Tier 495%9.8%
OTIS Mock AIME 2024-2025100%88.9%
ProofBench100%21%
LMArena Math—1418
FrontierMath (Feb 2025 set)—28.3%
FrontierMath Tier 4 (v1)—2.1%

Knowledge Claude Opus 5.5 leads

Claude Opus 5.5: 66.6 (#9), GPT-5.4 mini: 51.4 (#62)

Knowledge benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
GPQA Diamond90.6%86.9%
SimpleQA Verified72.2%29.4%
LMArena Expert15641434
Vectara Hallucination Rate—5.5%

Multimodal Claude Opus 5.5 leads

Claude Opus 5.5: 56.5 (#2), GPT-5.4 mini: 39.0 (#51)

Multimodal benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
LMArena Vision—1245
Furniture Assembly83.3%—

Multilingual Claude Opus 5.5 leads

Claude Opus 5.5: 59.8 (#1), GPT-5.4 mini: 52.1 (#94)

Multilingual benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
LMArena Non-English15131405
LMArena Chinese15721446
LMArena Russian15321417
LMArena French—1440
LMArena German—1407
LMArena Japanese—1375
LMArena Korean—1369
LMArena Spanish—1403

Instruction Following Claude Opus 5.5 leads

Claude Opus 5.5: 80.1 (#2), GPT-5.4 mini: 74.3 (#99)

Instruction Following benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
LMArena Instruction Following15351405

Long Context Claude Opus 5.5 leads

Claude Opus 5.5: 47.3 (#18), GPT-5.4 mini: 42.9 (#107)

Long Context benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
LMArena Longer Query15401407

Writing & Preference Claude Opus 5.5 leads

Claude Opus 5.5: 78.7 (#3), GPT-5.4 mini: 64.2 (#56)

Writing & Preference benchmarks
BenchmarkClaude Opus 5.5GPT-5.4 mini
LMArena Text15181411
LMArena Creative Writing15381370
EQ-Bench Creative Writing20501665
LMArena Multi-Turn15201429

Frequently asked questions

Is Claude Opus 5.5 better than GPT-5.4 mini?

Claude Opus 5.5 is the stronger model overall, scoring 68.5 to 44.8 on the Noometry Index. GPT-5.4 mini costs 4.7× less per token, which makes it the better buy when Claude Opus 5.5's lead doesn't matter for your workload.

Which is cheaper, Claude Opus 5.5 or GPT-5.4 mini?

GPT-5.4 mini is cheaper. It lists at $0.75 per million input tokens and $4.50 per million output tokens; Claude Opus 5.5 lists at $4 and $20.

Is Claude Opus 5.5 or GPT-5.4 mini better for coding?

Claude Opus 5.5 scores higher on coding benchmarks: 71.4 versus 45.0 in the Noometry coding category.

Which has the bigger context window?

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

How many benchmarks do Claude Opus 5.5 and GPT-5.4 mini share?

28 benchmarks have published results for both models. Claude Opus 5.5 has 35 scored results on Noometry and GPT-5.4 mini has 46.

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