GPT-5.3 Instant Benchmark Scores & Performance

Benchmark analysis of GPT-5.3 Instant by OpenAI across 32 sourced tests on BenchLM.

According to BenchLM.ai, GPT-5.3 Instant ranks #6 out of 123 models with an overall score of 87/100. This places it in the upper tier of AI models, with competitive scores across most benchmark categories.

GPT-5.3 Instant is a proprietary model with a 128K token context window. It uses explicit chain-of-thought reasoning, which typically improves performance on math and complex reasoning tasks at the cost of higher latency and token usage.

Its strongest category is Instruction Following (#3), while its weakest is Agentic (#9). This performance profile makes it a well-rounded choice across a range of tasks.

Creator

OpenAI

Source Type

Proprietary

Reasoning

Reasoning

Context Window

128K

Overall Score

87#6 of 123

Arena Elo

1438

Knowledge Benchmarks

MMLU
99
GPQA
98
SuperGPQA
96
OpenBookQA
94
MMLU-Pro
89
HLE
44
FrontierScience
92

Coding Benchmarks

HumanEval
88
SWE-bench Verified
76
LiveCodeBench
75
SWE-bench Pro
83

Mathematics Benchmarks

AIME 2023
99
AIME 2024
99
AIME 2025
98
HMMT Feb 2023
95
HMMT Feb 2024
97
HMMT Feb 2025
96
BRUMO 2025
96
MATH-500
98

Reasoning Benchmarks

SimpleQA
96
MuSR
94
BBH
97
LongBench v2
92
MRCRv2
94

Agentic Benchmarks

Terminal-Bench 2.0
86
BrowseComp
82
OSWorld-Verified
80

Multimodal & Grounded Benchmarks

MMMU-Pro
95
OfficeQA Pro
95

Instruction Following Benchmarks

IFEval
96

Multilingual Benchmarks

MGSM
96
MMLU-ProX
92

Frequently Asked Questions

How does GPT-5.3 Instant perform overall in AI benchmarks?

GPT-5.3 Instant ranks #6 out of 123 models with an overall score of 87. It is created by OpenAI and features a 128K context window.

Is GPT-5.3 Instant good for knowledge and understanding?

GPT-5.3 Instant ranks #4 out of 123 models in knowledge and understanding benchmarks with an average score of 80.8. It is among the top performers in this category.

Is GPT-5.3 Instant good for coding and programming?

GPT-5.3 Instant ranks #7 out of 123 models in coding and programming benchmarks with an average score of 78.7. It is among the top performers in this category.

Is GPT-5.3 Instant good for mathematics?

GPT-5.3 Instant ranks #6 out of 123 models in mathematics benchmarks with an average score of 97.2. It is among the top performers in this category.

Is GPT-5.3 Instant good for reasoning and logic?

GPT-5.3 Instant ranks #5 out of 123 models in reasoning and logic benchmarks with an average score of 94.2. It is among the top performers in this category.

Is GPT-5.3 Instant good for agentic tool use and computer tasks?

GPT-5.3 Instant ranks #9 out of 123 models in agentic tool use and computer tasks benchmarks with an average score of 82.9. It is among the top performers in this category.

Is GPT-5.3 Instant good for multimodal and grounded tasks?

GPT-5.3 Instant ranks #4 out of 123 models in multimodal and grounded tasks benchmarks with an average score of 95. It is among the top performers in this category.

Is GPT-5.3 Instant good for instruction following?

GPT-5.3 Instant ranks #3 out of 123 models in instruction following benchmarks with an average score of 96. It is among the top performers in this category.

Is GPT-5.3 Instant good for multilingual tasks?

GPT-5.3 Instant ranks #7 out of 123 models in multilingual tasks benchmarks with an average score of 93.4. It is among the top performers in this category.

What is the context window size of GPT-5.3 Instant?

GPT-5.3 Instant has a context window of 128K, which determines how much text it can process in a single interaction.

Last updated: March 12, 2026

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