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 45. 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 22. The single biggest benchmark swing on the page is SWE-bench Pro, 85 to 22.
GPT-5.3-Codex-Spark is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.05 input / $0.40 output per 1M tokens for GPT-5 nano. That is roughly 20.0x on output cost alone. GPT-5 nano gives you the larger context window at 400K, compared with 256K for GPT-5.3-Codex-Spark.
Pick GPT-5.3-Codex-Spark if you want the stronger benchmark profile. GPT-5 nano only becomes the better choice if you want the cheaper token bill or you need the larger 400K context window.
GPT-5.3-Codex-Spark
85.6
GPT-5 nano
37.7
GPT-5.3-Codex-Spark
82.3
GPT-5 nano
22
GPT-5.3-Codex-Spark
88.3
GPT-5 nano
56.7
GPT-5.3-Codex-Spark
92.7
GPT-5 nano
58.8
GPT-5.3-Codex-Spark
78.3
GPT-5 nano
63.7
Comparable scores for this category are coming soon. One or both models do not have sourced results here yet.
GPT-5.3-Codex-Spark
90.8
GPT-5 nano
48
GPT-5.3-Codex-Spark
96.7
GPT-5 nano
85.2
GPT-5.3-Codex-Spark is ahead overall, 87 to 45. The biggest single separator in this matchup is SWE-bench Pro, where the scores are 85 and 22.
GPT-5.3-Codex-Spark has the edge for knowledge tasks in this comparison, averaging 78.3 versus 63.7. Inside this category, FrontierScience 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 22. Inside this category, SWE-bench Pro 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 85.2. Inside this category, AIME 2025 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 58.8. Inside this category, LongBench v2 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 37.7. Inside this category, OSWorld-Verified 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 56.7. Inside this category, OfficeQA Pro 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 48. Inside this category, MMLU-ProX 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.