GPT-5.3 Codex vs K-Exaone

Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.

GPT-5.3 Codex is clearly ahead on the aggregate, 80 to 49. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.3 Codex's sharpest advantage is in coding, where it averages 66.2 against 49.4. The single biggest benchmark swing on the page is SWE-bench Verified, 85% to 49.4%.

GPT-5.3 Codex gives you the larger context window at 400K, compared with 256K for K-Exaone.

Quick Verdict

Pick GPT-5.3 Codex if you want the stronger benchmark profile. K-Exaone only becomes the better choice if its workflow or ecosystem matters more than the raw scoreboard.

Agentic

Coming soon

Benchmark data for this category is coming soon.

Coding

GPT-5.3 Codex

GPT-5.3 Codex

66.2

K-Exaone

49.4

95%
HumanEval
Coming soon
85%
SWE-bench Verified
49.4%
58.2%
SWE-Rebench
Coming soon

Multimodal & Grounded

Coming soon

Benchmark data for this category is coming soon.

Reasoning

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

93%
MuSR
Coming soon

Knowledge

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

99%
MMLU
Coming soon
97%
GPQA
Coming soon
95%
SuperGPQA
Coming soon
90%
MMLU-Pro
Coming soon
95%
SimpleQA
Coming soon

Instruction Following

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

93%
IFEval
Coming soon

Multilingual

Coming soon

Benchmark data for this category is coming soon.

Mathematics

Coming soon

Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.

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

Frequently Asked Questions

Which is better, GPT-5.3 Codex or K-Exaone?

GPT-5.3 Codex is ahead overall, 80 to 49. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 85% and 49.4%.

Which is better for coding, GPT-5.3 Codex or K-Exaone?

GPT-5.3 Codex has the edge for coding in this comparison, averaging 66.2 versus 49.4. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

Last updated: March 18, 2026

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