Side-by-side benchmark comparison across agentic, coding, multimodal, knowledge, reasoning, and math workflows.
GPT-5.3-Codex-Spark is clearly ahead on the aggregate, 87 to 56. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.3-Codex-Spark's sharpest advantage is in coding, where it averages 82.3 against 27.6. The single biggest benchmark swing on the page is SWE-bench Verified, 80 to 24.
GPT-5.3-Codex-Spark is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.08 input / $0.30 output per 1M tokens for Seed 1.6 Flash. That is roughly 26.7x on output cost alone.
Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. Seed 1.6 Flash only becomes the better choice if you want the cheaper token bill.
GPT-5.3-Codex-Spark
85.6
Seed 1.6 Flash
54.5
GPT-5.3-Codex-Spark
82.3
Seed 1.6 Flash
27.6
GPT-5.3-Codex-Spark
88.3
Seed 1.6 Flash
73.1
GPT-5.3-Codex-Spark
92.7
Seed 1.6 Flash
66.8
GPT-5.3-Codex-Spark
78.3
Seed 1.6 Flash
47.3
GPT-5.3-Codex-Spark
92
Seed 1.6 Flash
81
GPT-5.3-Codex-Spark
90.8
Seed 1.6 Flash
72.8
GPT-5.3-Codex-Spark
96.7
Seed 1.6 Flash
67.1
GPT-5.3-Codex-Spark is ahead overall, 87 to 56. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 80 and 24.
GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 47.3. Inside this category, HLE is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for coding in this comparison, averaging 82.3 versus 27.6. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for math in this comparison, averaging 96.7 versus 67.1. Inside this category, AIME 2023 is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for reasoning in this comparison, averaging 92.7 versus 66.8. Inside this category, SimpleQA is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for agentic tasks in this comparison, averaging 85.6 versus 54.5. Inside this category, Terminal-Bench 2.0 is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for multimodal and grounded tasks in this comparison, averaging 88.3 versus 73.1. Inside this category, OfficeQA Pro is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for instruction following in this comparison, averaging 92 versus 81. Inside this category, IFEval is the benchmark that creates the most daylight between them.
GPT-5.3-Codex-Spark has the edge for multilingual tasks in this comparison, averaging 90.8 versus 72.8. Inside this category, MGSM is the benchmark that creates the most daylight between them.
Get notified when new models drop, benchmark scores change, or the leaderboard shifts. One email per week.
Free. No spam. Unsubscribe anytime. We only store derived location metadata for consent routing.