Model comparison

GPT-5.4 vs GPT-5.5

GPT-5.5 is the stronger model overall, scoring 63.4 to 59.4 on the Noometry Index. GPT-5.4 costs 2.0× less per token, which makes it the better buy when GPT-5.5's lead doesn't matter for your workload.

Last verified . 62 shared benchmarks.

GPT-5.4 OpenAI

59.4

Rank #16 Confirmed

GPT-5.5 OpenAI

63.4

Rank #9 Confirmed

Summary

  • They share 62 benchmarks with published results for both. GPT-5.4 scores higher in 2 categories and GPT-5.5 in 8 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in reasoning, where GPT-5.5 leads 72.8 to 61.8.
  • The biggest single-benchmark swing is Kagi LLM Benchmark: 63.8% for GPT-5.4 and 88.8% for GPT-5.5.
  • GPT-5.4 is cheaper at $2.50 / $15 per million input/output tokens, against $5 / $30 for GPT-5.5.

Side by side

GPT-5.4 and GPT-5.5 specifications
GPT-5.4GPT-5.5
ProviderOpenAIOpenAI
Noometry Index59.463.4
Released2026-03-052026-04-23
WeightsProprietaryProprietary
Context window1.05M1.05M
Max output128K128K
Input $ / M tokens$2.50$5
Output $ / M tokens$15$30
Results tracked6871

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Category by category

Coding GPT-5.5 leads

GPT-5.4: 52.6 (#33), GPT-5.5: 58.2 (#17)

Coding benchmarks
BenchmarkGPT-5.4GPT-5.5
SWE-bench Verified76.9%80.6%
DeepSWE51.8%67%
LMArena WebDev14651513
SciCode56.6%56.1%
GSO31.4%40.2%
WeirdML77.7%84.9%
LMArena Coding14971494
MirrorCode15.6%10%
ALE-Bench1,6071,943
FrontierCode—43%
AlgoTune1.85—

Agentic & Tool Use GPT-5.5 leads

GPT-5.4: 46.5 (#13), GPT-5.5: 50.7 (#6)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.4GPT-5.5
Terminal-Bench81.8%84.7%
APEX-Agents52.4%55.1%
τ²-bench Banking39.4%44.6%
DeepResearch Bench35.1%54%
PostTrainBench19%27.2%
GBAEval45.1%53.2%
LMArena Search11971242
Vending-Bench 26,1447,524
OSWorld 2.0—13%
Remote Labor Index—6.3%
ExploitBench—47.4%
GDP.pdf—26%
METR Time Horizons74.3%—

Reasoning GPT-5.5 leads

GPT-5.4: 61.8 (#19), GPT-5.5: 72.8 (#11)

Reasoning benchmarks
BenchmarkGPT-5.4GPT-5.5
ARC-AGI-274%85%
Kagi LLM Benchmark63.8%88.8%
NYT Connections (extended)91.3%96.2%
ARC-AGI-193.7%95%
CritPt23.4%27.1%
Chess Puzzles44%54%
EBR-Bench25.4%34.3%
LMArena Hard Prompts14851489
Mystery Game Puzzles37%56%
DTBench94.4%96%
LMCA52%54.3%
Epoch Capabilities Index156.81159.1
ForecastBench59.560.6
SimpleBench—69%
EnigmaEval16%—
Thematic Generalization80%—
Surface Evolver Bench—88.1%
Bench to the Future 3—0.14

Math GPT-5.5 leads

GPT-5.4: 73.5 (#19), GPT-5.5: 81.7 (#11)

Knowledge Too close to call

GPT-5.4: 65.3 (#14), GPT-5.5: 64.4 (#17)

Knowledge benchmarks
BenchmarkGPT-5.4GPT-5.5
GPQA Diamond93.3%94%
SimpleQA Verified45.1%63%
Vectara Hallucination Rate7%9.3%
LMArena Expert15071508
Humanity's Last Exam36.2%—

Multimodal GPT-5.5 leads

GPT-5.4: 43.7 (#20), GPT-5.5: 46.9 (#12)

Multimodal benchmarks
BenchmarkGPT-5.4GPT-5.5
LMArena Vision13031297
Blueprint-Bench 227.1%36.2%
Furniture Assembly37.5%44.2%
LMArena Document14711486

Multilingual Too close to call

GPT-5.4: 56.2 (#23), GPT-5.5: 56.4 (#20)

Multilingual benchmarks
BenchmarkGPT-5.4GPT-5.5
LMArena Non-English14651467
LMArena Chinese15191533
LMArena French14931486
LMArena German14721480
LMArena Japanese14851498
LMArena Korean14481460
LMArena Russian14801473
LMArena Spanish14541468

Instruction Following Too close to call

GPT-5.4: 77.1 (#27), GPT-5.5: 77.5 (#18)

Instruction Following benchmarks
BenchmarkGPT-5.4GPT-5.5
LMArena Instruction Following14691479

Long Context GPT-5.4 leads

GPT-5.4: 50.3 (#8), GPT-5.5: 48.3 (#12)

Long Context benchmarks
BenchmarkGPT-5.4GPT-5.5
CL-bench Life21.7%22.2%
LMArena Longer Query14731484
CL-bench27.9%—

Writing & Preference Too close to call

GPT-5.4: 71.9 (#17), GPT-5.5: 72.7 (#13)

Writing & Preference benchmarks
BenchmarkGPT-5.4GPT-5.5
LMArena Text14691472
LMArena Creative Writing14391455
EQ-Bench Creative Writing18401844
EQ-Bench 412721315
LMArena Multi-Turn14821476

Frequently asked questions

Is GPT-5.4 better than GPT-5.5?

GPT-5.5 is the stronger model overall, scoring 63.4 to 59.4 on the Noometry Index. GPT-5.4 costs 2.0× less per token, which makes it the better buy when GPT-5.5's lead doesn't matter for your workload.

Which is cheaper, GPT-5.4 or GPT-5.5?

GPT-5.4 is cheaper. It lists at $2.50 per million input tokens and $15 per million output tokens; GPT-5.5 lists at $5 and $30.

Is GPT-5.4 or GPT-5.5 better for coding?

GPT-5.5 scores higher on coding benchmarks: 58.2 versus 52.6 in the Noometry coding category.

Which has the bigger context window?

Both accept 1.05M tokens.

How many benchmarks do GPT-5.4 and GPT-5.5 share?

62 benchmarks have published results for both models. GPT-5.4 has 68 scored results on Noometry and GPT-5.5 has 71.

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