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 53. 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 24.7. The single biggest benchmark swing on the page is LiveCodeBench, 85 to 21.
GPT-5.3 Codex is also the more expensive model on tokens at $2.50 input / $10.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for Seed-2.0-Mini. That is roughly 25.0x on output cost alone. GPT-5.3 Codex is the reasoning model in the pair, while Seed-2.0-Mini 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 256K for Seed-2.0-Mini.
Pick GPT-5.3 Codex if you want the stronger benchmark profile. Seed-2.0-Mini 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.
GPT-5.3 Codex
88.1
Seed-2.0-Mini
46.2
GPT-5.3 Codex
87.3
Seed-2.0-Mini
24.7
GPT-5.3 Codex
91.3
Seed-2.0-Mini
73.1
GPT-5.3 Codex
93.7
Seed-2.0-Mini
64.8
GPT-5.3 Codex
80.3
Seed-2.0-Mini
44.6
GPT-5.3 Codex
93
Seed-2.0-Mini
80
GPT-5.3 Codex
92.8
Seed-2.0-Mini
71.8
GPT-5.3 Codex
97.7
Seed-2.0-Mini
65.1
GPT-5.3 Codex is ahead overall, 89 to 53. The biggest single separator in this matchup is LiveCodeBench, where the scores are 85 and 21.
GPT-5.3 Codex has the edge for knowledge tasks in this comparison, averaging 80.3 versus 44.6. Inside this category, HLE is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for coding in this comparison, averaging 87.3 versus 24.7. Inside this category, LiveCodeBench is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for math in this comparison, averaging 97.7 versus 65.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for reasoning in this comparison, averaging 93.7 versus 64.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for agentic tasks in this comparison, averaging 88.1 versus 46.2. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for multimodal and grounded tasks in this comparison, averaging 91.3 versus 73.1. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for instruction following in this comparison, averaging 93 versus 80. Inside this category, IFEval is the benchmark that creates the most daylight between them.
GPT-5.3 Codex has the edge for multilingual tasks in this comparison, averaging 92.8 versus 71.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.
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