Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.3 Codex
85
Sakana Fugu Ultra
100
Pick Sakana Fugu Ultra if you want the stronger benchmark profile. GPT-5.3 Codex only becomes the better choice if you want the cheaper token bill.
Agentic
+10.6 difference
Coding
+20.4 difference
GPT-5.3 Codex
Sakana Fugu Ultra
$1.75 / $14
$5 / $30
79 t/s
N/A
88.26s
N/A
400K
1M
Pick Sakana Fugu Ultra if you want the stronger benchmark profile. GPT-5.3 Codex only becomes the better choice if you want the cheaper token bill.
Sakana Fugu Ultra is clearly ahead on the provisional aggregate, 100 to 85. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Sakana Fugu Ultra's sharpest advantage is in coding, where it averages 83.5 against 63.1. The single biggest benchmark swing on the page is SWE-bench Pro, 56.8% to 73.7%.
Sakana Fugu Ultra is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $1.75 input / $14.00 output per 1M tokens for GPT-5.3 Codex. That is roughly 2.1x on output cost alone. Sakana Fugu Ultra gives you the larger context window at 1M, compared with 400K for GPT-5.3 Codex.
Sakana Fugu Ultra is ahead on BenchLM's provisional leaderboard, 100 to 85. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 56.8% and 73.7%.
Sakana Fugu Ultra has the edge for coding in this comparison, averaging 83.5 versus 63.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
Sakana Fugu Ultra has the edge for agentic tasks in this comparison, averaging 82.1 versus 71.5. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
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