GPT-5.3 Codex vs Ministral 3 8B

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

GPT-5.3 Codex is clearly ahead on the aggregate, 89 to 32. 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 87.3 against 14.2. The single biggest benchmark swing on the page is SWE-bench Pro, 90 to 13.

GPT-5.3 Codex is also the more expensive model on tokens at $2.50 input / $10.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Ministral 3 8B. That is roughly Infinityx on output cost alone. GPT-5.3 Codex is the reasoning model in the pair, while Ministral 3 8B is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.3 Codex gives you the larger context window at 400K, compared with 128K for Ministral 3 8B.

Quick Verdict

Pick GPT-5.3 Codex if you want the stronger benchmark profile. Ministral 3 8B only becomes the better choice if you want the cheaper token bill or you would rather avoid the extra latency and token burn of a reasoning model.

Agentic

GPT-5.3 Codex

GPT-5.3 Codex

88.1

Ministral 3 8B

28.9

90
Terminal-Bench 2.0
26
88
BrowseComp
36
86
OSWorld-Verified
27

Coding

GPT-5.3 Codex

GPT-5.3 Codex

87.3

Ministral 3 8B

14.2

95
HumanEval
23
85
SWE-bench Verified
16
85
LiveCodeBench
15
90
SWE-bench Pro
13

Multimodal & Grounded

GPT-5.3 Codex

GPT-5.3 Codex

91.3

Ministral 3 8B

32.4

89
MMMU-Pro
27
94
OfficeQA Pro
39

Reasoning

GPT-5.3 Codex

GPT-5.3 Codex

93.7

Ministral 3 8B

36.1

95
SimpleQA
28
93
MuSR
26
98
BBH
63
92
LongBench v2
38
93
MRCRv2
41

Knowledge

GPT-5.3 Codex

GPT-5.3 Codex

80.3

Ministral 3 8B

28

99
MMLU
28
97
GPQA
27
95
SuperGPQA
25
93
OpenBookQA
23
90
MMLU-Pro
52
44
HLE
3
90
FrontierScience
32

Instruction Following

GPT-5.3 Codex

GPT-5.3 Codex

93

Ministral 3 8B

69

93
IFEval
69

Multilingual

GPT-5.3 Codex

GPT-5.3 Codex

92.8

Ministral 3 8B

61.7

96
MGSM
63
91
MMLU-ProX
61

Mathematics

GPT-5.3 Codex

GPT-5.3 Codex

97.7

Ministral 3 8B

43.3

99
AIME 2023
30
99
AIME 2024
32
98
AIME 2025
33
95
HMMT Feb 2023
26
97
HMMT Feb 2024
28
96
HMMT Feb 2025
27
96
BRUMO 2025
29
99
MATH-500
60

Frequently Asked Questions

Which is better, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex is ahead overall, 89 to 32. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 90 and 13.

Which is better for knowledge tasks, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for knowledge tasks in this comparison, averaging 80.3 versus 28. Inside this category, MMLU is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for coding in this comparison, averaging 87.3 versus 14.2. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for math in this comparison, averaging 97.7 versus 43.3. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.

Which is better for reasoning, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for reasoning in this comparison, averaging 93.7 versus 36.1. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for agentic tasks in this comparison, averaging 88.1 versus 28.9. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for multimodal and grounded tasks in this comparison, averaging 91.3 versus 32.4. Inside this category, MMMU-Pro is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for instruction following in this comparison, averaging 93 versus 69. Inside this category, IFEval is the benchmark that creates the most daylight between them.

Which is better for multilingual tasks, GPT-5.3 Codex or Ministral 3 8B?

GPT-5.3 Codex has the edge for multilingual tasks in this comparison, averaging 92.8 versus 61.7. Inside this category, MGSM is the benchmark that creates the most daylight between them.

Last updated: March 12, 2026

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